settings: Use a derive macro for refine (#38451)

When we refactored settings to not pass JSON blobs around, we ended up
needing
to write *a lot* of code that just merged things (like json merge used
to do).

Use a derive macro to prevent typos in this logic.

Release Notes:

- N/A

crates/settings/src/base_keymap_setting.rs

@@ -2,21 +2,17 @@ use std::fmt::{Display, Formatter};
 
 use crate::{
     self as settings,
-    settings_content::{self, BaseKeymapContent, SettingsContent},
+    settings_content::{BaseKeymapContent, SettingsContent},
 };
 use gpui::App;
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
-use serde_with::skip_serializing_none;
 use settings::{Settings, VsCodeSettings};
-use settings_ui_macros::{SettingsKey, SettingsUi};
 
 /// Base key bindings scheme. Base keymaps can be overridden with user keymaps.
 ///
 /// Default: VSCode
-#[derive(
-    Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq, Default, SettingsUi,
-)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq, Default)]
 pub enum BaseKeymap {
     #[default]
     VSCode,
@@ -134,37 +130,11 @@ impl BaseKeymap {
     }
 }
 
-#[derive(
-    Copy,
-    Clone,
-    Debug,
-    Serialize,
-    Deserialize,
-    JsonSchema,
-    PartialEq,
-    Eq,
-    Default,
-    SettingsUi,
-    SettingsKey,
-)]
-// extracted so that it can be an option, and still work with derive(SettingsUi)
-#[settings_key(None)]
-#[skip_serializing_none]
-pub struct BaseKeymapSetting {
-    pub base_keymap: Option<BaseKeymap>,
-}
-
 impl Settings for BaseKeymap {
-    fn from_defaults(s: &crate::settings_content::SettingsContent, _cx: &mut App) -> Self {
+    fn from_settings(s: &crate::settings_content::SettingsContent, _cx: &mut App) -> Self {
         s.base_keymap.unwrap().into()
     }
 
-    fn refine(&mut self, s: &settings_content::SettingsContent, _cx: &mut App) {
-        if let Some(base_keymap) = s.base_keymap {
-            *self = base_keymap.into();
-        };
-    }
-
     fn import_from_vscode(_vscode: &VsCodeSettings, current: &mut SettingsContent) {
         current.base_keymap = Some(BaseKeymapContent::VSCode);
     }

crates/settings/src/merge_from.rs

@@ -0,0 +1,164 @@
+use std::rc::Rc;
+
+/// Trait for recursively merging settings structures.
+///
+/// This trait allows settings objects to be merged from optional sources,
+/// where `None` values are ignored and `Some` values override existing values.
+///
+/// HashMaps, structs and similar types are merged by combining their contents key-wise,
+/// but all other types (including Vecs) are last-write-wins.
+/// (Though see also ExtendingVec and SaturatingBool)
+#[allow(unused)]
+pub trait MergeFrom {
+    /// Merge from an optional source of the same type.
+    /// If `other` is `None`, no changes are made.
+    /// If `other` is `Some(value)`, fields from `value` are merged into `self`.
+    fn merge_from(&mut self, other: Option<&Self>);
+}
+
+macro_rules! merge_from_overwrites {
+    ($($type:ty),+) => {
+        $(
+            impl MergeFrom for $type {
+                fn merge_from(&mut self, other: Option<&Self>) {
+                    if let Some(value) = other {
+                        *self = value.clone();
+                    }
+                }
+            }
+        )+
+    }
+}
+
+merge_from_overwrites!(
+    u16,
+    u32,
+    u64,
+    usize,
+    i16,
+    i32,
+    i64,
+    bool,
+    f64,
+    f32,
+    std::num::NonZeroUsize,
+    std::num::NonZeroU32,
+    String,
+    std::sync::Arc<str>,
+    gpui::SharedString,
+    std::path::PathBuf,
+    gpui::Modifiers,
+    gpui::FontFeatures
+);
+
+impl<T: Clone> MergeFrom for Vec<T> {
+    fn merge_from(&mut self, other: Option<&Self>) {
+        if let Some(other) = other {
+            *self = other.clone()
+        }
+    }
+}
+
+// Implementations for collections that extend/merge their contents
+impl<K, V> MergeFrom for collections::HashMap<K, V>
+where
+    K: Clone + std::hash::Hash + Eq,
+    V: Clone + MergeFrom,
+{
+    fn merge_from(&mut self, other: Option<&Self>) {
+        let Some(other) = other else { return };
+        for (k, v) in other {
+            if let Some(existing) = self.get_mut(k) {
+                existing.merge_from(Some(v));
+            } else {
+                self.insert(k.clone(), v.clone());
+            }
+        }
+    }
+}
+
+impl<K, V> MergeFrom for collections::BTreeMap<K, V>
+where
+    K: Clone + std::hash::Hash + Eq + Ord,
+    V: Clone + MergeFrom,
+{
+    fn merge_from(&mut self, other: Option<&Self>) {
+        let Some(other) = other else { return };
+        for (k, v) in other {
+            if let Some(existing) = self.get_mut(k) {
+                existing.merge_from(Some(v));
+            } else {
+                self.insert(k.clone(), v.clone());
+            }
+        }
+    }
+}
+
+impl<K, V> MergeFrom for collections::IndexMap<K, V>
+where
+    K: std::hash::Hash + Eq + Clone,
+    // Q: ?Sized + std::hash::Hash + collections::Equivalent<K> + Eq,
+    V: Clone + MergeFrom,
+{
+    fn merge_from(&mut self, other: Option<&Self>) {
+        let Some(other) = other else { return };
+        for (k, v) in other {
+            if let Some(existing) = self.get_mut(k) {
+                existing.merge_from(Some(v));
+            } else {
+                self.insert(k.clone(), v.clone());
+            }
+        }
+    }
+}
+
+impl<T> MergeFrom for collections::BTreeSet<T>
+where
+    T: Clone + Ord,
+{
+    fn merge_from(&mut self, other: Option<&Self>) {
+        let Some(other) = other else { return };
+        for item in other {
+            self.insert(item.clone());
+        }
+    }
+}
+
+impl<T> MergeFrom for collections::HashSet<T>
+where
+    T: Clone + std::hash::Hash + Eq,
+{
+    fn merge_from(&mut self, other: Option<&Self>) {
+        let Some(other) = other else { return };
+        for item in other {
+            self.insert(item.clone());
+        }
+    }
+}
+
+impl MergeFrom for serde_json::Value {
+    fn merge_from(&mut self, other: Option<&Self>) {
+        let Some(other) = other else { return };
+        match (self, other) {
+            (serde_json::Value::Object(this), serde_json::Value::Object(other)) => {
+                for (k, v) in other {
+                    if let Some(existing) = this.get_mut(k) {
+                        existing.merge_from(other.get(k));
+                    } else {
+                        this.insert(k.clone(), v.clone());
+                    }
+                }
+            }
+            (this, other) => *this = other.clone(),
+        }
+    }
+}
+
+impl<T: MergeFrom + Clone> MergeFrom for Rc<T> {
+    fn merge_from(&mut self, other: Option<&Self>) {
+        let Some(other) = other else { return };
+        let mut this: T = self.as_ref().clone();
+        this.merge_from(Some(other.as_ref()));
+        *self = Rc::new(this)
+    }
+}

crates/settings/src/settings.rs

@@ -1,6 +1,7 @@
 mod base_keymap_setting;
 mod editable_setting_control;
 mod keymap_file;
+pub mod merge_from;
 mod settings_content;
 mod settings_file;
 mod settings_json;
@@ -27,8 +28,7 @@ pub use settings_store::{
     InvalidSettingsError, LocalSettingsKind, Settings, SettingsKey, SettingsLocation, SettingsStore,
 };
 pub use settings_ui_core::*;
-// Re-export the derive macro
-pub use settings_ui_macros::{SettingsKey, SettingsUi};
+
 pub use vscode_import::{VsCodeSettings, VsCodeSettingsSource};
 
 #[derive(Clone, Debug, PartialEq)]

crates/settings/src/settings_content.rs

@@ -22,15 +22,16 @@ use release_channel::ReleaseChannel;
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 use serde_with::skip_serializing_none;
+use settings_macros::MergeFrom;
 use std::collections::BTreeSet;
 use std::env;
 use std::sync::Arc;
 pub use util::serde::default_true;
 
-use crate::ActiveSettingsProfileName;
+use crate::{ActiveSettingsProfileName, merge_from};
 
 #[skip_serializing_none]
-#[derive(Debug, PartialEq, Default, Clone, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, PartialEq, Default, Clone, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct SettingsContent {
     #[serde(flatten)]
     pub project: ProjectSettingsContent,
@@ -153,7 +154,7 @@ pub struct SettingsContent {
     /// Whether to disable all AI features in Zed.
     ///
     /// Default: false
-    pub disable_ai: Option<bool>,
+    pub disable_ai: Option<SaturatingBool>,
 
     /// Settings related to Vim mode in Zed.
     pub vim: Option<VimSettingsContent>,
@@ -166,14 +167,14 @@ impl SettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Debug, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct ServerSettingsContent {
     #[serde(flatten)]
     pub project: ProjectSettingsContent,
 }
 
 #[skip_serializing_none]
-#[derive(Debug, Default, PartialEq, Clone, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, Default, PartialEq, Clone, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct UserSettingsContent {
     #[serde(flatten)]
     pub content: Box<SettingsContent>,
@@ -225,7 +226,9 @@ impl UserSettingsContent {
 /// Base key bindings scheme. Base keymaps can be overridden with user keymaps.
 ///
 /// Default: VSCode
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq, Default)]
+#[derive(
+    Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq, Default,
+)]
 pub enum BaseKeymapContent {
     #[default]
     VSCode,
@@ -239,7 +242,7 @@ pub enum BaseKeymapContent {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, PartialEq, Default, Serialize, Deserialize, JsonSchema, Debug)]
+#[derive(Clone, PartialEq, Default, Serialize, Deserialize, JsonSchema, MergeFrom, Debug)]
 pub struct TitleBarSettingsContent {
     /// Controls when the title bar is visible: "always" | "never" | "hide_in_full_screen".
     ///
@@ -275,7 +278,7 @@ pub struct TitleBarSettingsContent {
     pub show_menus: Option<bool>,
 }
 
-#[derive(Copy, Clone, PartialEq, Serialize, Deserialize, JsonSchema, Debug)]
+#[derive(Copy, Clone, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom, Debug)]
 #[serde(rename_all = "snake_case")]
 pub enum TitleBarVisibility {
     Always,
@@ -285,7 +288,7 @@ pub enum TitleBarVisibility {
 
 /// Configuration of audio in Zed.
 #[skip_serializing_none]
-#[derive(Clone, PartialEq, Default, Serialize, Deserialize, JsonSchema, Debug)]
+#[derive(Clone, PartialEq, Default, Serialize, Deserialize, JsonSchema, MergeFrom, Debug)]
 pub struct AudioSettingsContent {
     /// Opt into the new audio system.
     #[serde(rename = "experimental.rodio_audio", default)]
@@ -307,7 +310,7 @@ pub struct AudioSettingsContent {
 
 /// Control what info is collected by Zed.
 #[skip_serializing_none]
-#[derive(Default, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema, Debug)]
+#[derive(Default, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema, Debug, MergeFrom)]
 pub struct TelemetrySettingsContent {
     /// Send debug info like crash reports.
     ///
@@ -320,7 +323,7 @@ pub struct TelemetrySettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Default, Debug, PartialEq, Eq, Serialize, Deserialize, JsonSchema, Clone)]
+#[derive(Default, Debug, PartialEq, Eq, Serialize, Deserialize, JsonSchema, Clone, MergeFrom)]
 pub struct DebuggerSettingsContent {
     /// Determines the stepping granularity.
     ///
@@ -353,7 +356,9 @@ pub struct DebuggerSettingsContent {
 }
 
 /// The granularity of one 'step' in the stepping requests `next`, `stepIn`, `stepOut`, and `stepBack`.
-#[derive(PartialEq, Eq, Debug, Hash, Clone, Copy, Deserialize, Serialize, JsonSchema)]
+#[derive(
+    PartialEq, Eq, Debug, Hash, Clone, Copy, Deserialize, Serialize, JsonSchema, MergeFrom,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum SteppingGranularity {
     /// The step should allow the program to run until the current statement has finished executing.
@@ -366,7 +371,7 @@ pub enum SteppingGranularity {
     Instruction,
 }
 
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 #[serde(rename_all = "snake_case")]
 pub enum DockPosition {
     Left,
@@ -376,7 +381,7 @@ pub enum DockPosition {
 
 /// Settings for slash commands.
 #[skip_serializing_none]
-#[derive(Deserialize, Serialize, Debug, Default, Clone, JsonSchema, PartialEq, Eq)]
+#[derive(Deserialize, Serialize, Debug, Default, Clone, JsonSchema, MergeFrom, PartialEq, Eq)]
 pub struct SlashCommandSettings {
     /// Settings for the `/cargo-workspace` slash command.
     pub cargo_workspace: Option<CargoWorkspaceCommandSettings>,
@@ -384,7 +389,7 @@ pub struct SlashCommandSettings {
 
 /// Settings for the `/cargo-workspace` slash command.
 #[skip_serializing_none]
-#[derive(Deserialize, Serialize, Debug, Default, Clone, JsonSchema, PartialEq, Eq)]
+#[derive(Deserialize, Serialize, Debug, Default, Clone, JsonSchema, MergeFrom, PartialEq, Eq)]
 pub struct CargoWorkspaceCommandSettings {
     /// Whether `/cargo-workspace` is enabled.
     pub enabled: Option<bool>,
@@ -392,7 +397,7 @@ pub struct CargoWorkspaceCommandSettings {
 
 /// Configuration of voice calls in Zed.
 #[skip_serializing_none]
-#[derive(Clone, PartialEq, Default, Serialize, Deserialize, JsonSchema, Debug)]
+#[derive(Clone, PartialEq, Default, Serialize, Deserialize, JsonSchema, MergeFrom, Debug)]
 pub struct CallSettingsContent {
     /// Whether the microphone should be muted when joining a channel or a call.
     ///
@@ -406,7 +411,7 @@ pub struct CallSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Deserialize, Serialize, PartialEq, Debug, Default, Clone, JsonSchema)]
+#[derive(Deserialize, Serialize, PartialEq, Debug, Default, Clone, JsonSchema, MergeFrom)]
 pub struct ExtensionSettingsContent {
     /// The extensions that should be automatically installed by Zed.
     ///
@@ -421,7 +426,7 @@ pub struct ExtensionSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, PartialEq, Default, Serialize, Deserialize, JsonSchema, Debug)]
+#[derive(Clone, PartialEq, Default, Serialize, Deserialize, JsonSchema, MergeFrom, Debug)]
 pub struct GitPanelSettingsContent {
     /// Whether to show the panel button in the status bar.
     ///
@@ -462,7 +467,9 @@ pub struct GitPanelSettingsContent {
     pub collapse_untracked_diff: Option<bool>,
 }
 
-#[derive(Default, Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(
+    Default, Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum StatusStyle {
     #[default]
@@ -471,13 +478,13 @@ pub enum StatusStyle {
 }
 
 #[skip_serializing_none]
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 pub struct ScrollbarSettings {
     pub show: Option<ShowScrollbar>,
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Default, Serialize, Deserialize, JsonSchema, Debug, PartialEq)]
+#[derive(Clone, Default, Serialize, Deserialize, JsonSchema, MergeFrom, Debug, PartialEq)]
 pub struct NotificationPanelSettingsContent {
     /// Whether to show the panel button in the status bar.
     ///
@@ -494,7 +501,7 @@ pub struct NotificationPanelSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Default, Serialize, Deserialize, JsonSchema, Debug, PartialEq)]
+#[derive(Clone, Default, Serialize, Deserialize, JsonSchema, MergeFrom, Debug, PartialEq)]
 pub struct PanelSettingsContent {
     /// Whether to show the panel button in the status bar.
     ///
@@ -511,7 +518,7 @@ pub struct PanelSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Default, Serialize, Deserialize, JsonSchema, Debug, PartialEq)]
+#[derive(Clone, Default, Serialize, Deserialize, JsonSchema, MergeFrom, Debug, PartialEq)]
 pub struct MessageEditorSettings {
     /// Whether to automatically replace emoji shortcodes with emoji characters.
     /// For example: typing `:wave:` gets replaced with `👋`.
@@ -521,7 +528,7 @@ pub struct MessageEditorSettings {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Default, Serialize, Deserialize, JsonSchema, Debug, PartialEq)]
+#[derive(Clone, Default, Serialize, Deserialize, JsonSchema, MergeFrom, Debug, PartialEq)]
 pub struct FileFinderSettingsContent {
     /// Whether to show file icons in the file finder.
     ///
@@ -549,10 +556,12 @@ pub struct FileFinderSettingsContent {
     ///
     /// Default: None
     /// todo() -> Change this type to an enum
-    pub include_ignored: Option<Option<bool>>,
+    pub include_ignored: Option<bool>,
 }
 
-#[derive(Debug, PartialEq, Eq, Clone, Copy, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(
+    Debug, PartialEq, Eq, Clone, Copy, Default, Serialize, Deserialize, JsonSchema, MergeFrom,
+)]
 #[serde(rename_all = "lowercase")]
 pub enum FileFinderWidthContent {
     #[default]
@@ -564,7 +573,7 @@ pub enum FileFinderWidthContent {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Default, Serialize, Deserialize, PartialEq, Debug, JsonSchema)]
+#[derive(Clone, Default, Serialize, Deserialize, PartialEq, Debug, JsonSchema, MergeFrom)]
 pub struct VimSettingsContent {
     pub default_mode: Option<ModeContent>,
     pub toggle_relative_line_numbers: Option<bool>,
@@ -575,7 +584,7 @@ pub struct VimSettingsContent {
     pub cursor_shape: Option<CursorShapeSettings>,
 }
 
-#[derive(Copy, Clone, Default, Serialize, Deserialize, JsonSchema, PartialEq, Debug)]
+#[derive(Copy, Clone, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Debug)]
 #[serde(rename_all = "snake_case")]
 pub enum ModeContent {
     #[default]
@@ -585,7 +594,7 @@ pub enum ModeContent {
 }
 
 /// Controls when to use system clipboard.
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum UseSystemClipboard {
     /// Don't use system clipboard.
@@ -598,7 +607,7 @@ pub enum UseSystemClipboard {
 
 /// The settings for cursor shape.
 #[skip_serializing_none]
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 pub struct CursorShapeSettings {
     /// Cursor shape for the normal mode.
     ///
@@ -620,7 +629,7 @@ pub struct CursorShapeSettings {
 
 /// Settings specific to journaling
 #[skip_serializing_none]
-#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 pub struct JournalSettingsContent {
     /// The path of the directory where journal entries are stored.
     ///
@@ -632,7 +641,7 @@ pub struct JournalSettingsContent {
     pub hour_format: Option<HourFormat>,
 }
 
-#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 #[serde(rename_all = "snake_case")]
 pub enum HourFormat {
     #[default]
@@ -641,7 +650,7 @@ pub enum HourFormat {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Default, Serialize, Deserialize, JsonSchema, Debug, PartialEq)]
+#[derive(Clone, Default, Serialize, Deserialize, JsonSchema, MergeFrom, Debug, PartialEq)]
 pub struct OutlinePanelSettingsContent {
     /// Whether to show the outline panel button in the status bar.
     ///
@@ -695,14 +704,14 @@ pub struct OutlinePanelSettingsContent {
     pub expand_outlines_with_depth: Option<usize>,
 }
 
-#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, Copy, PartialEq)]
+#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, Copy, PartialEq)]
 #[serde(rename_all = "snake_case")]
 pub enum DockSide {
     Left,
     Right,
 }
 
-#[derive(Copy, Clone, Debug, PartialEq, Eq, Deserialize, Serialize, JsonSchema)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Deserialize, Serialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum ShowIndentGuides {
     Always,
@@ -710,13 +719,13 @@ pub enum ShowIndentGuides {
 }
 
 #[skip_serializing_none]
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 pub struct IndentGuidesSettingsContent {
     /// When to show the scrollbar in the outline panel.
     pub show: Option<ShowIndentGuides>,
 }
 
-#[derive(Clone, Copy, Default, PartialEq, Debug, JsonSchema, Deserialize, Serialize)]
+#[derive(Clone, Copy, Default, PartialEq, Debug, JsonSchema, MergeFrom, Deserialize, Serialize)]
 #[serde(rename_all = "snake_case")]
 pub enum LineIndicatorFormat {
     Short,
@@ -726,7 +735,7 @@ pub enum LineIndicatorFormat {
 
 /// The settings for the image viewer.
 #[skip_serializing_none]
-#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, Default, PartialEq)]
+#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, Default, PartialEq)]
 pub struct ImageViewerSettingsContent {
     /// The unit to use for displaying image file sizes.
     ///
@@ -735,7 +744,7 @@ pub struct ImageViewerSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Copy, Debug, Serialize, Deserialize, JsonSchema, Default, PartialEq)]
+#[derive(Clone, Copy, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, Default, PartialEq)]
 #[serde(rename_all = "snake_case")]
 pub enum ImageFileSizeUnit {
     /// Displays file size in binary units (e.g., KiB, MiB).
@@ -746,7 +755,7 @@ pub enum ImageFileSizeUnit {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 pub struct RemoteSettingsContent {
     pub ssh_connections: Option<Vec<SshConnection>>,
     pub wsl_connections: Option<Vec<WslConnection>>,
@@ -754,7 +763,7 @@ pub struct RemoteSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, Default, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[derive(Clone, Debug, Default, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom)]
 pub struct SshConnection {
     pub host: SharedString,
     pub username: Option<String>,
@@ -774,7 +783,7 @@ pub struct SshConnection {
     pub port_forwards: Option<Vec<SshPortForwardOption>>,
 }
 
-#[derive(Clone, Default, Serialize, Deserialize, PartialEq, JsonSchema, Debug)]
+#[derive(Clone, Default, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom, Debug)]
 pub struct WslConnection {
     pub distro_name: SharedString,
     pub user: Option<String>,
@@ -791,7 +800,7 @@ pub struct SshProject {
 }
 
 #[skip_serializing_none]
-#[derive(Debug, Clone, PartialEq, Eq, Hash, Deserialize, Serialize, JsonSchema)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Deserialize, Serialize, JsonSchema, MergeFrom)]
 pub struct SshPortForwardOption {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub local_host: Option<String>,
@@ -803,7 +812,7 @@ pub struct SshPortForwardOption {
 
 /// Settings for configuring REPL display and behavior.
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct ReplSettingsContent {
     /// Maximum number of lines to keep in REPL's scrollback buffer.
     /// Clamped with [4, 256] range.
@@ -816,3 +825,42 @@ pub struct ReplSettingsContent {
     /// Default: 128
     pub max_columns: Option<usize>,
 }
+
+#[derive(Default, Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct ExtendingVec<T>(pub Vec<T>);
+
+impl<T> Into<Vec<T>> for ExtendingVec<T> {
+    fn into(self) -> Vec<T> {
+        self.0
+    }
+}
+impl<T> From<Vec<T>> for ExtendingVec<T> {
+    fn from(vec: Vec<T>) -> Self {
+        ExtendingVec(vec)
+    }
+}
+
+impl<T: Clone> merge_from::MergeFrom for ExtendingVec<T> {
+    fn merge_from(&mut self, other: Option<&Self>) {
+        if let Some(other) = other {
+            self.0.extend_from_slice(other.0.as_slice());
+        }
+    }
+}
+
+#[derive(Debug, Default, Copy, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct SaturatingBool(pub bool);
+
+impl From<bool> for SaturatingBool {
+    fn from(value: bool) -> Self {
+        SaturatingBool(value)
+    }
+}
+
+impl merge_from::MergeFrom for SaturatingBool {
+    fn merge_from(&mut self, other: Option<&Self>) {
+        if let Some(other) = other {
+            self.0 |= other.0
+        }
+    }
+}

crates/settings/src/settings_content/agent.rs

@@ -3,12 +3,13 @@ use gpui::SharedString;
 use schemars::{JsonSchema, json_schema};
 use serde::{Deserialize, Serialize};
 use serde_with::skip_serializing_none;
+use settings_macros::MergeFrom;
 use std::{borrow::Cow, path::PathBuf, sync::Arc};
 
 use crate::DockPosition;
 
 #[skip_serializing_none]
-#[derive(Clone, PartialEq, Serialize, Deserialize, JsonSchema, Debug, Default)]
+#[derive(Clone, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom, Debug, Default)]
 pub struct AgentSettingsContent {
     /// Whether the Agent is enabled.
     ///
@@ -168,7 +169,7 @@ impl AgentSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Debug, PartialEq, Clone, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, PartialEq, Clone, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct AgentProfileContent {
     pub name: Arc<str>,
     #[serde(default)]
@@ -180,12 +181,12 @@ pub struct AgentProfileContent {
 }
 
 #[skip_serializing_none]
-#[derive(Debug, PartialEq, Clone, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, PartialEq, Clone, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct ContextServerPresetContent {
     pub tools: IndexMap<Arc<str>, bool>,
 }
 
-#[derive(Copy, Clone, Default, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Copy, Clone, Default, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum DefaultAgentView {
     #[default]
@@ -193,7 +194,7 @@ pub enum DefaultAgentView {
     TextThread,
 }
 
-#[derive(Copy, Clone, Default, Debug, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Copy, Clone, Default, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 #[serde(rename_all = "snake_case")]
 pub enum NotifyWhenAgentWaiting {
     #[default]
@@ -203,13 +204,13 @@ pub enum NotifyWhenAgentWaiting {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 pub struct LanguageModelSelection {
     pub provider: LanguageModelProviderSetting,
     pub model: String,
 }
 
-#[derive(Clone, Copy, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Default)]
+#[derive(Clone, Copy, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Default)]
 #[serde(rename_all = "snake_case")]
 pub enum CompletionMode {
     #[default]
@@ -219,14 +220,14 @@ pub enum CompletionMode {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 pub struct LanguageModelParameters {
     pub provider: Option<LanguageModelProviderSetting>,
     pub model: Option<SharedString>,
     pub temperature: Option<f32>,
 }
 
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, MergeFrom)]
 pub struct LanguageModelProviderSetting(pub String);
 
 impl JsonSchema for LanguageModelProviderSetting {
@@ -277,7 +278,7 @@ impl From<&str> for LanguageModelProviderSetting {
 }
 
 #[skip_serializing_none]
-#[derive(Default, PartialEq, Deserialize, Serialize, Clone, JsonSchema, Debug)]
+#[derive(Default, PartialEq, Deserialize, Serialize, Clone, JsonSchema, MergeFrom, Debug)]
 pub struct AllAgentServersSettings {
     pub gemini: Option<BuiltinAgentServerSettings>,
     pub claude: Option<BuiltinAgentServerSettings>,
@@ -288,7 +289,7 @@ pub struct AllAgentServersSettings {
 }
 
 #[skip_serializing_none]
-#[derive(Default, Deserialize, Serialize, Clone, JsonSchema, Debug, PartialEq)]
+#[derive(Default, Deserialize, Serialize, Clone, JsonSchema, MergeFrom, Debug, PartialEq)]
 pub struct BuiltinAgentServerSettings {
     /// Absolute path to a binary to be used when launching this agent.
     ///
@@ -320,7 +321,7 @@ pub struct BuiltinAgentServerSettings {
 }
 
 #[skip_serializing_none]
-#[derive(Deserialize, Serialize, Clone, JsonSchema, Debug, PartialEq)]
+#[derive(Deserialize, Serialize, Clone, JsonSchema, MergeFrom, Debug, PartialEq)]
 pub struct CustomAgentServerSettings {
     #[serde(rename = "command")]
     pub path: PathBuf,

crates/settings/src/settings_content/editor.rs

@@ -4,11 +4,12 @@ use collections::HashMap;
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 use serde_with::skip_serializing_none;
+use settings_macros::MergeFrom;
 
 use crate::{DiagnosticSeverityContent, ShowScrollbar};
 
 #[skip_serializing_none]
-#[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct EditorSettingsContent {
     /// Whether the cursor blinks in the editor.
     ///
@@ -194,7 +195,7 @@ pub struct EditorSettingsContent {
 
 // Status bar related settings
 #[skip_serializing_none]
-#[derive(Debug, Clone, Default, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Debug, Clone, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 pub struct StatusBarContent {
     /// Whether to display the active language button in the status bar.
     ///
@@ -208,7 +209,7 @@ pub struct StatusBarContent {
 
 // Toolbar related settings
 #[skip_serializing_none]
-#[derive(Debug, Clone, Default, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Debug, Clone, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 pub struct ToolbarContent {
     /// Whether to display breadcrumbs in the editor toolbar.
     ///
@@ -235,7 +236,7 @@ pub struct ToolbarContent {
 
 /// Scrollbar related settings
 #[skip_serializing_none]
-#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Default)]
+#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Default)]
 pub struct ScrollbarContent {
     /// When to show the scrollbar in the editor.
     ///
@@ -271,7 +272,7 @@ pub struct ScrollbarContent {
 
 /// Minimap related settings
 #[skip_serializing_none]
-#[derive(Clone, Default, Debug, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Clone, Default, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 pub struct MinimapContent {
     /// When to show the minimap in the editor.
     ///
@@ -296,7 +297,7 @@ pub struct MinimapContent {
     /// How to highlight the current line in the minimap.
     ///
     /// Default: inherits editor line highlights setting
-    pub current_line_highlight: Option<Option<CurrentLineHighlight>>,
+    pub current_line_highlight: Option<CurrentLineHighlight>,
 
     /// Maximum number of columns to display in the minimap.
     ///
@@ -306,7 +307,7 @@ pub struct MinimapContent {
 
 /// Forcefully enable or disable the scrollbar for each axis
 #[skip_serializing_none]
-#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Default)]
+#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Default)]
 pub struct ScrollbarAxesContent {
     /// When false, forcefully disables the horizontal scrollbar. Otherwise, obey other settings.
     ///
@@ -321,7 +322,7 @@ pub struct ScrollbarAxesContent {
 
 /// Gutter related settings
 #[skip_serializing_none]
-#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 pub struct GutterContent {
     /// Whether to show line numbers in the gutter.
     ///
@@ -346,7 +347,9 @@ pub struct GutterContent {
 }
 
 /// How to render LSP `textDocument/documentColor` colors in the editor.
-#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(
+    Copy, Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum DocumentColorsRenderMode {
     /// Do not query and render document colors.
@@ -360,7 +363,7 @@ pub enum DocumentColorsRenderMode {
     Background,
 }
 
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum CurrentLineHighlight {
     // Don't highlight the current line.
@@ -374,7 +377,7 @@ pub enum CurrentLineHighlight {
 }
 
 /// When to populate a new search's query based on the text under the cursor.
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum SeedQuerySetting {
     /// Always populate the search query with the word under the cursor.
@@ -386,7 +389,9 @@ pub enum SeedQuerySetting {
 }
 
 /// What to do when multibuffer is double clicked in some of its excerpts (parts of singleton buffers).
-#[derive(Default, Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(
+    Default, Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum DoubleClickInMultibuffer {
     /// Behave as a regular buffer and select the whole word.
@@ -400,7 +405,9 @@ pub enum DoubleClickInMultibuffer {
 /// When to show the minimap thumb.
 ///
 /// Default: always
-#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(
+    Copy, Clone, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum MinimapThumb {
     /// Show the minimap thumb only when the mouse is hovering over the minimap.
@@ -413,7 +420,9 @@ pub enum MinimapThumb {
 /// Defines the border style for the minimap's scrollbar thumb.
 ///
 /// Default: left_open
-#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(
+    Copy, Clone, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum MinimapThumbBorder {
     /// Displays a border on all sides of the thumb.
@@ -432,7 +441,7 @@ pub enum MinimapThumbBorder {
 /// Which diagnostic indicators to show in the scrollbar.
 ///
 /// Default: all
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 #[serde(rename_all = "lowercase")]
 pub enum ScrollbarDiagnostics {
     /// Show all diagnostic levels: hint, information, warnings, error.
@@ -450,7 +459,7 @@ pub enum ScrollbarDiagnostics {
 /// The key to use for adding multiple cursors
 ///
 /// Default: alt
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 #[serde(rename_all = "snake_case")]
 pub enum MultiCursorModifier {
     Alt,
@@ -461,7 +470,7 @@ pub enum MultiCursorModifier {
 /// Whether the editor will scroll beyond the last line.
 ///
 /// Default: one_page
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 #[serde(rename_all = "snake_case")]
 pub enum ScrollBeyondLastLine {
     /// The editor will not scroll beyond the last line.
@@ -475,7 +484,9 @@ pub enum ScrollBeyondLastLine {
 }
 
 /// The shape of a selection cursor.
-#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(
+    Copy, Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum CursorShape {
     /// A vertical bar
@@ -490,7 +501,9 @@ pub enum CursorShape {
 }
 
 /// What to do when go to definition yields no results.
-#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(
+    Copy, Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum GoToDefinitionFallback {
     /// Disables the fallback.
@@ -503,7 +516,9 @@ pub enum GoToDefinitionFallback {
 /// Determines when the mouse cursor should be hidden in an editor or input box.
 ///
 /// Default: on_typing_and_movement
-#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(
+    Copy, Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum HideMouseMode {
     /// Never hide the mouse cursor
@@ -518,7 +533,9 @@ pub enum HideMouseMode {
 /// Determines how snippets are sorted relative to other completion items.
 ///
 /// Default: inline
-#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(
+    Copy, Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum SnippetSortOrder {
     /// Place snippets at the top of the completion list
@@ -534,7 +551,7 @@ pub enum SnippetSortOrder {
 
 /// Default options for buffer and project search items.
 #[skip_serializing_none]
-#[derive(Clone, Default, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Clone, Default, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 pub struct SearchSettingsContent {
     /// Whether to show the project search button in the status bar.
     pub button: Option<bool>,
@@ -545,7 +562,7 @@ pub struct SearchSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub struct JupyterContent {
     /// Whether the Jupyter feature is enabled.
@@ -561,7 +578,7 @@ pub struct JupyterContent {
 
 /// Whether to allow drag and drop text selection in buffer.
 #[skip_serializing_none]
-#[derive(Clone, Default, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Clone, Default, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 pub struct DragAndDropSelectionContent {
     /// When true, enables drag and drop text selection in buffer.
     ///
@@ -577,7 +594,9 @@ pub struct DragAndDropSelectionContent {
 /// When to show the minimap in the editor.
 ///
 /// Default: never
-#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(
+    Copy, Clone, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum ShowMinimap {
     /// Follow the visibility of the scrollbar.
@@ -592,7 +611,9 @@ pub enum ShowMinimap {
 /// Where to show the minimap in the editor.
 ///
 /// Default: all_editors
-#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(
+    Copy, Clone, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum DisplayIn {
     /// Show on all open editors.

crates/settings/src/settings_content/language.rs

@@ -8,10 +8,10 @@ use serde::{
     de::{self, IntoDeserializer, MapAccess, SeqAccess, Visitor},
 };
 use serde_with::skip_serializing_none;
+use settings_macros::MergeFrom;
 use std::sync::Arc;
-use util::schemars::replace_subschema;
 
-use crate::ParameterizedJsonSchema;
+use crate::{ExtendingVec, merge_from};
 
 #[skip_serializing_none]
 #[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize, JsonSchema)]
@@ -31,12 +31,50 @@ pub struct AllLanguageSettingsContent {
     /// Settings for associating file extensions and filenames
     /// with languages.
     #[serde(default)]
-    pub file_types: HashMap<Arc<str>, Vec<String>>,
+    pub file_types: HashMap<Arc<str>, ExtendingVec<String>>,
+}
+
+fn merge_option<T: merge_from::MergeFrom + Clone>(this: &mut Option<T>, other: Option<&T>) {
+    let Some(other) = other else { return };
+    if let Some(this) = this {
+        this.merge_from(Some(other));
+    } else {
+        this.replace(other.clone());
+    }
+}
+
+impl merge_from::MergeFrom for AllLanguageSettingsContent {
+    fn merge_from(&mut self, other: Option<&Self>) {
+        let Some(other) = other else { return };
+        self.file_types.merge_from(Some(&other.file_types));
+        merge_option(&mut self.features, other.features.as_ref());
+        merge_option(&mut self.edit_predictions, other.edit_predictions.as_ref());
+
+        // A user's global settings override the default global settings and
+        // all default language-specific settings.
+        //
+        self.defaults.merge_from(Some(&other.defaults));
+        for language_settings in self.languages.0.values_mut() {
+            language_settings.merge_from(Some(&other.defaults));
+        }
+
+        // A user's language-specific settings override default language-specific settings.
+        for (language_name, user_language_settings) in &other.languages.0 {
+            if let Some(existing) = self.languages.0.get_mut(language_name) {
+                existing.merge_from(Some(&user_language_settings));
+            } else {
+                let mut new_settings = self.defaults.clone();
+                new_settings.merge_from(Some(&user_language_settings));
+
+                self.languages.0.insert(language_name.clone(), new_settings);
+            }
+        }
+    }
 }
 
 /// The settings for enabling/disabling features.
 #[skip_serializing_none]
-#[derive(Debug, Clone, PartialEq, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, Clone, PartialEq, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub struct FeaturesContent {
     /// Determines which edit prediction provider to use.
@@ -44,7 +82,9 @@ pub struct FeaturesContent {
 }
 
 /// The provider that supplies edit predictions.
-#[derive(Copy, Clone, Debug, Default, Eq, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(
+    Copy, Clone, Debug, Default, Eq, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum EditPredictionProvider {
     None,
@@ -56,7 +96,7 @@ pub enum EditPredictionProvider {
 
 /// The contents of the edit prediction settings.
 #[skip_serializing_none]
-#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 pub struct EditPredictionSettingsContent {
     /// A list of globs representing files that edit predictions should be disabled for.
     /// This list adds to a pre-existing, sensible default set of globs.
@@ -73,7 +113,7 @@ pub struct EditPredictionSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 pub struct CopilotSettingsContent {
     /// HTTP/HTTPS proxy to use for Copilot.
     ///
@@ -90,7 +130,9 @@ pub struct CopilotSettingsContent {
 }
 
 /// The mode in which edit predictions should be displayed.
-#[derive(Copy, Clone, Debug, Default, Eq, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(
+    Copy, Clone, Debug, Default, Eq, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum EditPredictionsMode {
     /// If provider supports it, display inline when holding modifier key (e.g., alt).
@@ -104,7 +146,7 @@ pub enum EditPredictionsMode {
 }
 
 /// Controls the soft-wrapping behavior in the editor.
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum SoftWrap {
     /// Prefer a single line generally, unless an overly long line is encountered.
@@ -122,7 +164,7 @@ pub enum SoftWrap {
 
 /// The settings for a particular language.
 #[skip_serializing_none]
-#[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct LanguageSettingsContent {
     /// How many columns a tab should occupy.
     ///
@@ -289,7 +331,7 @@ pub struct LanguageSettingsContent {
 }
 
 /// Controls how whitespace should be displayedin the editor.
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum ShowWhitespaceSetting {
     /// Draw whitespace only for the selected text.
@@ -310,7 +352,7 @@ pub enum ShowWhitespaceSetting {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 pub struct WhitespaceMap {
     pub space: Option<String>,
     pub tab: Option<String>,
@@ -331,7 +373,7 @@ impl WhitespaceMap {
 }
 
 /// The behavior of `editor::Rewrap`.
-#[derive(Debug, PartialEq, Clone, Copy, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, PartialEq, Clone, Copy, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum RewrapBehavior {
     /// Only rewrap within comments.
@@ -344,7 +386,7 @@ pub enum RewrapBehavior {
 }
 
 #[skip_serializing_none]
-#[derive(Default, Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
+#[derive(Default, Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct JsxTagAutoCloseSettingsContent {
     /// Enables or disables auto-closing of JSX tags.
     pub enabled: Option<bool>,
@@ -352,7 +394,7 @@ pub struct JsxTagAutoCloseSettingsContent {
 
 /// The settings for inlay hints.
 #[skip_serializing_none]
-#[derive(Clone, Default, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Clone, Default, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 pub struct InlayHintSettingsContent {
     /// Global switch to toggle hints on and off.
     ///
@@ -434,7 +476,7 @@ impl InlayHintKind {
 
 /// Controls how completions are processed for this language.
 #[skip_serializing_none]
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, Default)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom, Default)]
 #[serde(rename_all = "snake_case")]
 pub struct CompletionSettingsContent {
     /// Controls how words are completed.
@@ -462,7 +504,7 @@ pub struct CompletionSettingsContent {
     pub lsp_insert_mode: Option<LspInsertMode>,
 }
 
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum LspInsertMode {
     /// Replaces text before the cursor, using the `insert` range described in the LSP specification.
@@ -478,7 +520,7 @@ pub enum LspInsertMode {
 }
 
 /// Controls how document's words are completed.
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum WordsCompletionMode {
     /// Always fetch document's words for completions along with LSP completions.
@@ -495,7 +537,7 @@ pub enum WordsCompletionMode {
 /// and configure default Prettier, used when no project-level Prettier installation is found.
 /// Prettier formatting is disabled by default.
 #[skip_serializing_none]
-#[derive(Default, Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
+#[derive(Default, Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct PrettierSettingsContent {
     /// Enables or disables formatting with Prettier for a given language.
     pub allowed: Option<bool>,
@@ -515,7 +557,7 @@ pub struct PrettierSettingsContent {
 }
 
 /// Controls the behavior of formatting files when they are saved.
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, MergeFrom)]
 pub enum FormatOnSave {
     /// Files should be formatted on save.
     On,
@@ -614,7 +656,7 @@ impl<'de> Deserialize<'de> for FormatOnSave {
 }
 
 /// Controls which formatter should be used when formatting code.
-#[derive(Clone, Debug, Default, PartialEq, Eq)]
+#[derive(Clone, Debug, Default, PartialEq, Eq, MergeFrom)]
 pub enum SelectedFormatter {
     /// Format files using Zed's Prettier integration (if applicable),
     /// or falling back to formatting via language server.
@@ -710,7 +752,7 @@ impl<'de> Deserialize<'de> for SelectedFormatter {
 }
 
 /// Controls which formatters should be used when formatting code.
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(untagged)]
 pub enum FormatterList {
     Single(Formatter),
@@ -733,7 +775,7 @@ impl AsRef<[Formatter]> for FormatterList {
 }
 
 /// Controls which formatter should be used when formatting code. If there are multiple formatters, they are executed in the order of declaration.
-#[derive(Clone, Default, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Clone, Default, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum Formatter {
     /// Format code using the current language server.
@@ -754,7 +796,7 @@ pub enum Formatter {
 
 /// The settings for indent guides.
 #[skip_serializing_none]
-#[derive(Default, Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
+#[derive(Default, Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct IndentGuideSettingsContent {
     /// Whether to display indent guides in the editor.
     ///
@@ -780,7 +822,7 @@ pub struct IndentGuideSettingsContent {
 
 /// The task settings for a particular language.
 #[skip_serializing_none]
-#[derive(Debug, Clone, Deserialize, PartialEq, Serialize, JsonSchema)]
+#[derive(Debug, Clone, Deserialize, PartialEq, Serialize, JsonSchema, MergeFrom)]
 pub struct LanguageTaskSettingsContent {
     /// Extra task variables to set for a particular language.
     #[serde(default)]
@@ -796,37 +838,15 @@ pub struct LanguageTaskSettingsContent {
     pub prefer_lsp: Option<bool>,
 }
 
-/// Map from language name to settings. Its `ParameterizedJsonSchema` allows only known language
-/// names in the keys.
+/// Map from language name to settings.
 #[skip_serializing_none]
-#[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct LanguageToSettingsMap(pub HashMap<SharedString, LanguageSettingsContent>);
 
-inventory::submit! {
-    ParameterizedJsonSchema {
-        add_and_get_ref: |generator, params, _cx| {
-            let language_settings_content_ref = generator
-                .subschema_for::<LanguageSettingsContent>()
-                .to_value();
-            replace_subschema::<LanguageToSettingsMap>(generator, || json_schema!({
-                "type": "object",
-                "properties": params
-                    .language_names
-                    .iter()
-                    .map(|name| {
-                        (
-                            name.clone(),
-                            language_settings_content_ref.clone(),
-                        )
-                    })
-                    .collect::<serde_json::Map<_, _>>()
-            }))
-        }
-    }
-}
-
 /// Determines how indent guides are colored.
-#[derive(Default, Debug, Copy, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
+#[derive(
+    Default, Debug, Copy, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema, MergeFrom,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum IndentGuideColoring {
     /// Do not render any lines for indent guides.
@@ -839,7 +859,9 @@ pub enum IndentGuideColoring {
 }
 
 /// Determines how indent guide backgrounds are colored.
-#[derive(Default, Debug, Copy, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
+#[derive(
+    Default, Debug, Copy, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema, MergeFrom,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum IndentGuideBackgroundColoring {
     /// Do not render any background for indent guides.

crates/settings/src/settings_content/language_model.rs

@@ -2,11 +2,12 @@ use collections::HashMap;
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 use serde_with::skip_serializing_none;
+use settings_macros::MergeFrom;
 
 use std::sync::Arc;
 
 #[skip_serializing_none]
-#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom)]
 pub struct AllLanguageModelSettingsContent {
     pub anthropic: Option<AnthropicSettingsContent>,
     pub bedrock: Option<AmazonBedrockSettingsContent>,
@@ -25,14 +26,14 @@ pub struct AllLanguageModelSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom)]
 pub struct AnthropicSettingsContent {
     pub api_url: Option<String>,
     pub available_models: Option<Vec<AnthropicAvailableModel>>,
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct AnthropicAvailableModel {
     /// The model's name in the Anthropic API. e.g. claude-3-5-sonnet-latest, claude-3-opus-20240229, etc
     pub name: String,
@@ -53,7 +54,7 @@ pub struct AnthropicAvailableModel {
 }
 
 #[skip_serializing_none]
-#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom)]
 pub struct AmazonBedrockSettingsContent {
     pub available_models: Option<Vec<BedrockAvailableModel>>,
     pub endpoint_url: Option<String>,
@@ -63,7 +64,7 @@ pub struct AmazonBedrockSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct BedrockAvailableModel {
     pub name: String,
     pub display_name: Option<String>,
@@ -74,7 +75,7 @@ pub struct BedrockAvailableModel {
     pub mode: Option<ModelMode>,
 }
 
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub enum BedrockAuthMethodContent {
     #[serde(rename = "named_profile")]
     NamedProfile,
@@ -86,14 +87,14 @@ pub enum BedrockAuthMethodContent {
 }
 
 #[skip_serializing_none]
-#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom)]
 pub struct OllamaSettingsContent {
     pub api_url: Option<String>,
     pub available_models: Option<Vec<OllamaAvailableModel>>,
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct OllamaAvailableModel {
     /// The model name in the Ollama API (e.g. "llama3.2:latest")
     pub name: String,
@@ -111,7 +112,7 @@ pub struct OllamaAvailableModel {
     pub supports_thinking: Option<bool>,
 }
 
-#[derive(Clone, Serialize, Deserialize, Debug, Eq, PartialEq, JsonSchema)]
+#[derive(Clone, Serialize, Deserialize, Debug, Eq, PartialEq, JsonSchema, MergeFrom)]
 #[serde(untagged)]
 pub enum KeepAlive {
     /// Keep model alive for N seconds
@@ -134,14 +135,14 @@ impl Default for KeepAlive {
 }
 
 #[skip_serializing_none]
-#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom)]
 pub struct LmStudioSettingsContent {
     pub api_url: Option<String>,
     pub available_models: Option<Vec<LmStudioAvailableModel>>,
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct LmStudioAvailableModel {
     pub name: String,
     pub display_name: Option<String>,
@@ -151,14 +152,14 @@ pub struct LmStudioAvailableModel {
 }
 
 #[skip_serializing_none]
-#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom)]
 pub struct DeepseekSettingsContent {
     pub api_url: Option<String>,
     pub available_models: Option<Vec<DeepseekAvailableModel>>,
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct DeepseekAvailableModel {
     pub name: String,
     pub display_name: Option<String>,
@@ -167,14 +168,14 @@ pub struct DeepseekAvailableModel {
 }
 
 #[skip_serializing_none]
-#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom)]
 pub struct MistralSettingsContent {
     pub api_url: Option<String>,
     pub available_models: Option<Vec<MistralAvailableModel>>,
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct MistralAvailableModel {
     pub name: String,
     pub display_name: Option<String>,
@@ -187,14 +188,14 @@ pub struct MistralAvailableModel {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom)]
 pub struct OpenAiSettingsContent {
     pub api_url: Option<String>,
     pub available_models: Option<Vec<OpenAiAvailableModel>>,
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct OpenAiAvailableModel {
     pub name: String,
     pub display_name: Option<String>,
@@ -204,7 +205,7 @@ pub struct OpenAiAvailableModel {
     pub reasoning_effort: Option<OpenAiReasoningEffort>,
 }
 
-#[derive(Debug, Serialize, Deserialize, PartialEq, Clone, JsonSchema)]
+#[derive(Debug, Serialize, Deserialize, PartialEq, Clone, JsonSchema, MergeFrom)]
 #[serde(rename_all = "lowercase")]
 pub enum OpenAiReasoningEffort {
     Minimal,
@@ -214,14 +215,14 @@ pub enum OpenAiReasoningEffort {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom)]
 pub struct OpenAiCompatibleSettingsContent {
     pub api_url: String,
     pub available_models: Vec<OpenAiCompatibleAvailableModel>,
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct OpenAiCompatibleAvailableModel {
     pub name: String,
     pub display_name: Option<String>,
@@ -233,7 +234,7 @@ pub struct OpenAiCompatibleAvailableModel {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct OpenAiCompatibleModelCapabilities {
     pub tools: bool,
     pub images: bool,
@@ -253,14 +254,14 @@ impl Default for OpenAiCompatibleModelCapabilities {
 }
 
 #[skip_serializing_none]
-#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom)]
 pub struct VercelSettingsContent {
     pub api_url: Option<String>,
     pub available_models: Option<Vec<VercelAvailableModel>>,
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct VercelAvailableModel {
     pub name: String,
     pub display_name: Option<String>,
@@ -270,14 +271,14 @@ pub struct VercelAvailableModel {
 }
 
 #[skip_serializing_none]
-#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom)]
 pub struct GoogleSettingsContent {
     pub api_url: Option<String>,
     pub available_models: Option<Vec<GoogleAvailableModel>>,
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct GoogleAvailableModel {
     pub name: String,
     pub display_name: Option<String>,
@@ -286,14 +287,14 @@ pub struct GoogleAvailableModel {
 }
 
 #[skip_serializing_none]
-#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom)]
 pub struct XAiSettingsContent {
     pub api_url: Option<String>,
     pub available_models: Option<Vec<XaiAvailableModel>>,
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct XaiAvailableModel {
     pub name: String,
     pub display_name: Option<String>,
@@ -303,13 +304,13 @@ pub struct XaiAvailableModel {
 }
 
 #[skip_serializing_none]
-#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom)]
 pub struct ZedDotDevSettingsContent {
     pub available_models: Option<Vec<ZedDotDevAvailableModel>>,
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct ZedDotDevAvailableModel {
     /// The provider of the language model.
     pub provider: ZedDotDevAvailableProvider,
@@ -336,7 +337,7 @@ pub struct ZedDotDevAvailableModel {
     pub mode: Option<ModelMode>,
 }
 
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "lowercase")]
 pub enum ZedDotDevAvailableProvider {
     Anthropic,
@@ -345,14 +346,14 @@ pub enum ZedDotDevAvailableProvider {
 }
 
 #[skip_serializing_none]
-#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom)]
 pub struct OpenRouterSettingsContent {
     pub api_url: Option<String>,
     pub available_models: Option<Vec<OpenRouterAvailableModel>>,
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct OpenRouterAvailableModel {
     pub name: String,
     pub display_name: Option<String>,
@@ -366,7 +367,7 @@ pub struct OpenRouterAvailableModel {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct OpenRouterProvider {
     order: Option<Vec<String>>,
     #[serde(default = "default_true")]
@@ -381,7 +382,7 @@ pub struct OpenRouterProvider {
     sort: Option<String>,
 }
 
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "lowercase")]
 pub enum DataCollection {
     Allow,
@@ -400,14 +401,16 @@ fn default_true() -> bool {
 
 /// Configuration for caching language model messages.
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct LanguageModelCacheConfiguration {
     pub max_cache_anchors: usize,
     pub should_speculate: bool,
     pub min_total_token: u64,
 }
 
-#[derive(Copy, Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
+#[derive(
+    Copy, Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema, MergeFrom,
+)]
 #[serde(tag = "type", rename_all = "lowercase")]
 pub enum ModelMode {
     #[default]

crates/settings/src/settings_content/project.rs

@@ -4,12 +4,13 @@ use collections::{BTreeMap, HashMap};
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 use serde_with::skip_serializing_none;
+use settings_macros::MergeFrom;
 use util::serde::default_true;
 
-use crate::{AllLanguageSettingsContent, SlashCommandSettings};
+use crate::{AllLanguageSettingsContent, ExtendingVec, SlashCommandSettings};
 
 #[skip_serializing_none]
-#[derive(Debug, PartialEq, Clone, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, PartialEq, Clone, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct ProjectSettingsContent {
     #[serde(flatten)]
     pub all_languages: AllLanguageSettingsContent,
@@ -43,11 +44,11 @@ pub struct ProjectSettingsContent {
     pub slash_commands: Option<SlashCommandSettings>,
 
     /// The list of custom Git hosting providers.
-    pub git_hosting_providers: Option<Vec<GitHostingProviderConfig>>,
+    pub git_hosting_providers: Option<ExtendingVec<GitHostingProviderConfig>>,
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct WorktreeSettingsContent {
     /// The displayed name of this project. If not set, the root directory name
     /// will be displayed.
@@ -81,11 +82,11 @@ pub struct WorktreeSettingsContent {
 
     /// Treat the files matching these globs as `.env` files.
     /// Default: ["**/.env*", "**/*.pem", "**/*.key", "**/*.cert", "**/*.crt", "**/secrets.yml"]
-    pub private_files: Option<Vec<String>>,
+    pub private_files: Option<ExtendingVec<String>>,
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, Hash)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom, Hash)]
 #[serde(rename_all = "snake_case")]
 pub struct LspSettings {
     pub binary: Option<BinarySettings>,
@@ -112,7 +113,9 @@ impl Default for LspSettings {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema, Hash)]
+#[derive(
+    Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom, Hash,
+)]
 pub struct BinarySettings {
     pub path: Option<String>,
     pub arguments: Option<Vec<String>>,
@@ -121,7 +124,9 @@ pub struct BinarySettings {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema, Hash)]
+#[derive(
+    Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom, Hash,
+)]
 pub struct FetchSettings {
     // Whether to consider pre-releases for fetching
     pub pre_release: Option<bool>,
@@ -129,7 +134,7 @@ pub struct FetchSettings {
 
 /// Common language server settings.
 #[skip_serializing_none]
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct GlobalLspSettingsContent {
     /// Whether to show the LSP servers button in the status bar.
     ///
@@ -138,7 +143,7 @@ pub struct GlobalLspSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub struct DapSettingsContent {
     pub binary: Option<String>,
@@ -147,7 +152,9 @@ pub struct DapSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Default, Copy, Clone, PartialEq, Eq, Debug, Serialize, Deserialize, JsonSchema)]
+#[derive(
+    Default, Copy, Clone, PartialEq, Eq, Debug, Serialize, Deserialize, JsonSchema, MergeFrom,
+)]
 pub struct SessionSettingsContent {
     /// Whether or not to restore unsaved buffers on restart.
     ///
@@ -158,7 +165,7 @@ pub struct SessionSettingsContent {
     pub restore_unsaved_buffers: Option<bool>,
 }
 
-#[derive(Deserialize, Serialize, Clone, PartialEq, Eq, JsonSchema, Debug)]
+#[derive(Deserialize, Serialize, Clone, PartialEq, Eq, JsonSchema, MergeFrom, Debug)]
 #[serde(tag = "source", rename_all = "snake_case")]
 pub enum ContextServerSettingsContent {
     Custom {
@@ -198,7 +205,7 @@ impl ContextServerSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Deserialize, Serialize, Clone, PartialEq, Eq, JsonSchema)]
+#[derive(Deserialize, Serialize, Clone, PartialEq, Eq, JsonSchema, MergeFrom)]
 pub struct ContextServerCommand {
     #[serde(rename = "command")]
     pub path: PathBuf,
@@ -234,7 +241,7 @@ impl std::fmt::Debug for ContextServerCommand {
 }
 
 #[skip_serializing_none]
-#[derive(Copy, Clone, Debug, PartialEq, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Copy, Clone, Debug, PartialEq, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct GitSettings {
     /// Whether or not to show the git gutter.
     ///
@@ -259,7 +266,7 @@ pub struct GitSettings {
     pub hunk_style: Option<GitHunkStyleSetting>,
 }
 
-#[derive(Clone, Copy, Debug, PartialEq, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Copy, Debug, PartialEq, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum GitGutterSetting {
     /// Show git gutter in tracked files.
@@ -270,7 +277,7 @@ pub enum GitGutterSetting {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Copy, Debug, PartialEq, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Copy, Debug, PartialEq, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub struct InlineBlameSettings {
     /// Whether or not to show git blame data inline in
@@ -299,7 +306,7 @@ pub struct InlineBlameSettings {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Copy, PartialEq, Debug, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Copy, PartialEq, Debug, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub struct BranchPickerSettingsContent {
     /// Whether to show author name as part of the commit information.
@@ -308,7 +315,7 @@ pub struct BranchPickerSettingsContent {
     pub show_author_name: Option<bool>,
 }
 
-#[derive(Clone, Copy, PartialEq, Debug, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Copy, PartialEq, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum GitHunkStyleSetting {
     /// Show unstaged hunks with a filled background and staged hunks hollow.
@@ -319,7 +326,7 @@ pub enum GitHunkStyleSetting {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct DiagnosticsSettingsContent {
     /// Whether to show the project diagnostics button in the status bar.
     pub button: Option<bool>,
@@ -335,7 +342,7 @@ pub struct DiagnosticsSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Copy, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Clone, Copy, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 pub struct LspPullDiagnosticsSettingsContent {
     /// Whether to pull for diagnostics or not.
     ///
@@ -349,7 +356,7 @@ pub struct LspPullDiagnosticsSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Copy, Debug, PartialEq, Serialize, Deserialize, JsonSchema, Eq)]
+#[derive(Clone, Copy, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom, Eq)]
 pub struct InlineDiagnosticsSettingsContent {
     /// Whether or not to show inline diagnostics
     ///
@@ -376,7 +383,7 @@ pub struct InlineDiagnosticsSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct NodeBinarySettings {
     /// The path to the Node binary.
     pub path: Option<String>,
@@ -386,7 +393,7 @@ pub struct NodeBinarySettings {
     pub ignore_system_version: Option<bool>,
 }
 
-#[derive(Clone, PartialEq, Debug, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, PartialEq, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum DirenvSettings {
     /// Load direnv configuration through a shell hook
@@ -397,7 +404,17 @@ pub enum DirenvSettings {
 }
 
 #[derive(
-    Clone, Copy, Debug, Eq, PartialEq, Ord, PartialOrd, Serialize, Deserialize, JsonSchema,
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    PartialEq,
+    Ord,
+    PartialOrd,
+    Serialize,
+    Deserialize,
+    JsonSchema,
+    MergeFrom,
 )]
 #[serde(rename_all = "snake_case")]
 pub enum DiagnosticSeverityContent {
@@ -412,7 +429,7 @@ pub enum DiagnosticSeverityContent {
 
 /// A custom Git hosting provider.
 #[skip_serializing_none]
-#[derive(Debug, PartialEq, Clone, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, PartialEq, Clone, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct GitHostingProviderConfig {
     /// The type of the provider.
     ///
@@ -426,7 +443,7 @@ pub struct GitHostingProviderConfig {
     pub name: String,
 }
 
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum GitHostingProviderKind {
     Github,

crates/settings/src/settings_content/terminal.rs

@@ -5,11 +5,12 @@ use gpui::{AbsoluteLength, FontFeatures, SharedString, px};
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 use serde_with::skip_serializing_none;
+use settings_macros::MergeFrom;
 
 use crate::FontFamilyName;
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct TerminalSettingsContent {
     /// What shell to use when opening a terminal.
     ///
@@ -127,7 +128,7 @@ pub struct TerminalSettingsContent {
 }
 
 /// Shell configuration to open the terminal with.
-#[derive(Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum Shell {
     /// Use the system's default terminal configuration in /etc/passwd
@@ -146,7 +147,7 @@ pub enum Shell {
     },
 }
 
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum WorkingDirectory {
     /// Use the current file's project directory.  Will Fallback to the
@@ -163,15 +164,15 @@ pub enum WorkingDirectory {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Copy, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Clone, Copy, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 pub struct ScrollbarSettingsContent {
     /// When to show the scrollbar in the terminal.
     ///
     /// Default: inherits editor scrollbar settings
-    pub show: Option<Option<ShowScrollbar>>,
+    pub show: Option<ShowScrollbar>,
 }
 
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, Default)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom, Default)]
 #[serde(rename_all = "snake_case")]
 pub enum TerminalLineHeight {
     /// Use a line height that's comfortable for reading, 1.618
@@ -198,7 +199,7 @@ impl TerminalLineHeight {
 /// When to show the scrollbar.
 ///
 /// Default: auto
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 #[serde(rename_all = "snake_case")]
 pub enum ShowScrollbar {
     /// Show the scrollbar if there's important information or
@@ -212,7 +213,9 @@ pub enum ShowScrollbar {
     Never,
 }
 
-#[derive(Clone, Copy, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(
+    Clone, Copy, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum CursorShapeContent {
     /// Cursor is a block like `█`.
@@ -226,7 +229,7 @@ pub enum CursorShapeContent {
     Hollow,
 }
 
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum TerminalBlink {
     /// Never blink the cursor, ignoring the terminal mode.
@@ -238,7 +241,7 @@ pub enum TerminalBlink {
     On,
 }
 
-#[derive(Clone, Copy, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Clone, Copy, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum AlternateScroll {
     On,
@@ -247,7 +250,7 @@ pub enum AlternateScroll {
 
 // Toolbar related settings
 #[skip_serializing_none]
-#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 pub struct TerminalToolbarContent {
     /// Whether to display the terminal title in breadcrumbs inside the terminal pane.
     /// Only shown if the terminal title is not empty.
@@ -259,7 +262,7 @@ pub struct TerminalToolbarContent {
     pub breadcrumbs: Option<bool>,
 }
 
-#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum VenvSettings {
     #[default]
@@ -297,7 +300,7 @@ impl VenvSettings {
     }
 }
 
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 #[serde(rename_all = "snake_case")]
 pub enum TerminalDockPosition {
     Left,
@@ -305,7 +308,7 @@ pub enum TerminalDockPosition {
     Right,
 }
 
-#[derive(Clone, Copy, Debug, Default, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Copy, Debug, Default, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum ActivateScript {
     #[default]

crates/settings/src/settings_content/theme.rs

@@ -4,6 +4,7 @@ use schemars::{JsonSchema, JsonSchema_repr};
 use serde::{Deserialize, Deserializer, Serialize};
 use serde_json::Value;
 use serde_repr::{Deserialize_repr, Serialize_repr};
+use settings_macros::MergeFrom;
 use std::sync::Arc;
 
 use serde_with::skip_serializing_none;
@@ -11,7 +12,7 @@ use serde_with::skip_serializing_none;
 /// Settings for rendering text in UI and text buffers.
 
 #[skip_serializing_none]
-#[derive(Clone, PartialEq, Debug, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, PartialEq, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct ThemeSettingsContent {
     /// The default font size for text in the UI.
     #[serde(default)]
@@ -53,7 +54,7 @@ pub struct ThemeSettingsContent {
     pub buffer_font_features: Option<FontFeatures>,
     /// The font size for the agent panel. Falls back to the UI font size if unset.
     #[serde(default)]
-    pub agent_font_size: Option<Option<f32>>,
+    pub agent_font_size: Option<f32>,
     /// The name of the Zed theme to use.
     #[serde(default)]
     pub theme: Option<ThemeSelection>,
@@ -93,7 +94,7 @@ fn default_font_fallbacks() -> Option<FontFallbacks> {
 }
 
 /// Represents the selection of a theme, which can be either static or dynamic.
-#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 #[serde(untagged)]
 pub enum ThemeSelection {
     /// A static theme selection, represented by a single theme name.
@@ -111,7 +112,7 @@ pub enum ThemeSelection {
 }
 
 /// Represents the selection of an icon theme, which can be either static or dynamic.
-#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 #[serde(untagged)]
 pub enum IconThemeSelection {
     /// A static icon theme selection, represented by a single icon theme name.
@@ -134,7 +135,9 @@ pub enum IconThemeSelection {
 /// `Light` and `Dark` will select their respective themes.
 ///
 /// `System` will select the theme based on the system's appearance.
-#[derive(Debug, PartialEq, Eq, Clone, Copy, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(
+    Debug, PartialEq, Eq, Clone, Copy, Default, Serialize, Deserialize, JsonSchema, MergeFrom,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum ThemeMode {
     /// Use the specified `light` theme.
@@ -163,6 +166,7 @@ pub enum ThemeMode {
     Serialize,
     Deserialize,
     JsonSchema,
+    MergeFrom,
 )]
 #[serde(rename_all = "snake_case")]
 pub enum UiDensity {
@@ -190,15 +194,14 @@ impl UiDensity {
     }
 }
 
-/// Newtype for font family name. Its `ParameterizedJsonSchema` lists the font families known at
-/// runtime.
+/// Font family name.
 #[skip_serializing_none]
-#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 #[serde(transparent)]
 pub struct FontFamilyName(pub Arc<str>);
 
 /// The buffer's line height.
-#[derive(Clone, Copy, Debug, Serialize, Deserialize, PartialEq, JsonSchema, Default)]
+#[derive(Clone, Copy, Debug, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom, Default)]
 #[serde(rename_all = "snake_case")]
 pub enum BufferLineHeight {
     /// A less dense line height.
@@ -226,7 +229,7 @@ where
 
 /// The content of a serialized theme.
 #[skip_serializing_none]
-#[derive(Debug, Clone, Default, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Debug, Clone, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 #[serde(default)]
 pub struct ThemeStyleContent {
     #[serde(default, rename = "background.appearance")]
@@ -249,31 +252,30 @@ pub struct ThemeStyleContent {
     pub syntax: IndexMap<String, HighlightStyleContent>,
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 pub struct AccentContent(pub Option<String>);
 
-#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 pub struct PlayerColorContent {
     pub cursor: Option<String>,
     pub background: Option<String>,
     pub selection: Option<String>,
 }
 
-/// Newtype for a theme name. Its `ParameterizedJsonSchema` lists the theme names known at runtime.
+/// Theme name.
 #[skip_serializing_none]
-#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 #[serde(transparent)]
 pub struct ThemeName(pub Arc<str>);
 
-/// Newtype for a icon theme name. Its `ParameterizedJsonSchema` lists the icon theme names known at
-/// runtime.
+/// Icon Theme Name
 #[skip_serializing_none]
-#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 #[serde(transparent)]
 pub struct IconThemeName(pub Arc<str>);
 
 #[skip_serializing_none]
-#[derive(Debug, Clone, Default, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Debug, Clone, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 #[serde(default)]
 pub struct ThemeColorsContent {
     /// Border color. Used for most borders, is usually a high contrast color.
@@ -778,7 +780,7 @@ pub struct ThemeColorsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Debug, Clone, Default, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Debug, Clone, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 #[serde(default)]
 pub struct HighlightStyleContent {
     pub color: Option<String>,
@@ -812,7 +814,7 @@ where
 }
 
 #[skip_serializing_none]
-#[derive(Debug, Clone, Default, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Debug, Clone, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 #[serde(default)]
 pub struct StatusColorsContent {
     /// Indicates some kind of conflict, like a file changed on disk while it was open, or
@@ -958,7 +960,7 @@ pub struct StatusColorsContent {
 }
 
 /// The background appearance of the window.
-#[derive(Debug, PartialEq, Clone, Copy, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, PartialEq, Clone, Copy, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum WindowBackgroundContent {
     Opaque,
@@ -976,7 +978,7 @@ impl Into<gpui::WindowBackgroundAppearance> for WindowBackgroundContent {
     }
 }
 
-#[derive(Debug, Clone, Copy, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Debug, Clone, Copy, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 #[serde(rename_all = "snake_case")]
 pub enum FontStyleContent {
     Normal,
@@ -994,7 +996,9 @@ impl From<FontStyleContent> for FontStyle {
     }
 }
 
-#[derive(Debug, Clone, Copy, Serialize_repr, Deserialize_repr, JsonSchema_repr, PartialEq)]
+#[derive(
+    Debug, Clone, Copy, Serialize_repr, Deserialize_repr, JsonSchema_repr, PartialEq, MergeFrom,
+)]
 #[repr(u16)]
 pub enum FontWeightContent {
     Thin = 100,

crates/settings/src/settings_content/workspace.rs

@@ -4,11 +4,12 @@ use collections::HashMap;
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 use serde_with::skip_serializing_none;
+use settings_macros::MergeFrom;
 
 use crate::{DockPosition, DockSide, ScrollbarSettingsContent, ShowIndentGuides};
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, PartialEq, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, PartialEq, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct WorkspaceSettingsContent {
     /// Active pane styling settings.
     pub active_pane_modifiers: Option<ActivePanelModifiers>,
@@ -108,7 +109,7 @@ pub struct WorkspaceSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Default, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Default, Debug, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct ItemSettingsContent {
     /// Whether to show the Git file status on a tab item.
     ///
@@ -138,7 +139,7 @@ pub struct ItemSettingsContent {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, JsonSchema, MergeFrom)]
 pub struct PreviewTabsSettingsContent {
     /// Whether to show opened editors as preview tabs.
     /// Preview tabs do not stay open, are reused until explicitly set to be kept open opened (via double-click or editing) and show file names in italic.
@@ -155,7 +156,7 @@ pub struct PreviewTabsSettingsContent {
     pub enable_preview_from_code_navigation: Option<bool>,
 }
 
-#[derive(Copy, Clone, Debug, PartialEq, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Copy, Clone, Debug, PartialEq, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "lowercase")]
 pub enum ClosePosition {
     Left,
@@ -163,7 +164,7 @@ pub enum ClosePosition {
     Right,
 }
 
-#[derive(Copy, Clone, Debug, PartialEq, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Copy, Clone, Debug, PartialEq, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "lowercase")]
 pub enum ShowCloseButton {
     Always,
@@ -172,7 +173,9 @@ pub enum ShowCloseButton {
     Hidden,
 }
 
-#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(
+    Copy, Clone, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum ShowDiagnostics {
     #[default]
@@ -181,7 +184,7 @@ pub enum ShowDiagnostics {
     All,
 }
 
-#[derive(Copy, Clone, Debug, PartialEq, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Copy, Clone, Debug, PartialEq, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum ActivateOnClose {
     #[default]
@@ -191,7 +194,7 @@ pub enum ActivateOnClose {
 }
 
 #[skip_serializing_none]
-#[derive(Copy, Clone, PartialEq, Debug, Default, Serialize, Deserialize, JsonSchema)]
+#[derive(Copy, Clone, PartialEq, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub struct ActivePanelModifiers {
     /// Size of the border surrounding the active pane.
@@ -209,7 +212,7 @@ pub struct ActivePanelModifiers {
     pub inactive_opacity: Option<f32>,
 }
 
-#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, PartialEq, JsonSchema)]
+#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, PartialEq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum BottomDockLayout {
     /// Contained between the left and right docks
@@ -223,7 +226,7 @@ pub enum BottomDockLayout {
     RightAligned,
 }
 
-#[derive(Copy, Clone, PartialEq, Default, Serialize, Deserialize, JsonSchema, Debug)]
+#[derive(Copy, Clone, PartialEq, Default, Serialize, Deserialize, JsonSchema, MergeFrom, Debug)]
 #[serde(rename_all = "snake_case")]
 pub enum CloseWindowWhenNoItems {
     /// Match platform conventions by default, so "on" on macOS and "off" everywhere else
@@ -245,7 +248,9 @@ impl CloseWindowWhenNoItems {
     }
 }
 
-#[derive(Copy, Clone, PartialEq, Eq, Default, Serialize, Deserialize, JsonSchema, Debug)]
+#[derive(
+    Copy, Clone, PartialEq, Eq, Default, Serialize, Deserialize, JsonSchema, MergeFrom, Debug,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum RestoreOnStartupBehavior {
     /// Always start with an empty editor
@@ -258,7 +263,7 @@ pub enum RestoreOnStartupBehavior {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, Default, Serialize, Deserialize, JsonSchema, Debug, PartialEq)]
+#[derive(Clone, Default, Serialize, Deserialize, JsonSchema, MergeFrom, Debug, PartialEq)]
 pub struct TabBarSettingsContent {
     /// Whether or not to show the tab bar in the editor.
     ///
@@ -274,7 +279,7 @@ pub struct TabBarSettingsContent {
     pub show_tab_bar_buttons: Option<bool>,
 }
 
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum AutosaveSetting {
     /// Disable autosave.
@@ -298,14 +303,14 @@ impl AutosaveSetting {
     }
 }
 
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum PaneSplitDirectionHorizontal {
     Up,
     Down,
 }
 
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema, MergeFrom)]
 #[serde(rename_all = "snake_case")]
 pub enum PaneSplitDirectionVertical {
     Left,
@@ -313,7 +318,7 @@ pub enum PaneSplitDirectionVertical {
 }
 
 #[skip_serializing_none]
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq)]
 #[serde(rename_all = "snake_case")]
 pub struct CenteredLayoutSettings {
     /// The relative width of the left padding of the central pane from the
@@ -328,7 +333,7 @@ pub struct CenteredLayoutSettings {
     pub right_padding: Option<f32>,
 }
 
-#[derive(Copy, Clone, Default, Serialize, Deserialize, JsonSchema, PartialEq, Debug)]
+#[derive(Copy, Clone, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Debug)]
 #[serde(rename_all = "snake_case")]
 pub enum OnLastWindowClosed {
     /// Match platform conventions by default, so don't quit on macOS, and quit on other platforms
@@ -348,7 +353,7 @@ impl OnLastWindowClosed {
 }
 
 #[skip_serializing_none]
-#[derive(Clone, PartialEq, Default, Serialize, Deserialize, JsonSchema, Debug)]
+#[derive(Clone, PartialEq, Default, Serialize, Deserialize, JsonSchema, MergeFrom, Debug)]
 pub struct ProjectPanelSettingsContent {
     /// Whether to show the project panel button in the status bar.
     ///
@@ -423,7 +428,9 @@ pub struct ProjectPanelSettingsContent {
     pub drag_and_drop: Option<bool>,
 }
 
-#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(
+    Copy, Clone, Debug, Default, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq,
+)]
 #[serde(rename_all = "snake_case")]
 pub enum ProjectPanelEntrySpacing {
     /// Comfortable spacing of entries.
@@ -434,7 +441,7 @@ pub enum ProjectPanelEntrySpacing {
 }
 
 #[skip_serializing_none]
-#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, MergeFrom, PartialEq, Eq)]
 pub struct ProjectPanelIndentGuidesSettings {
     pub show: Option<ShowIndentGuides>,
 }

crates/settings/src/settings_json.rs

@@ -1,5 +1,5 @@
 use anyhow::Result;
-use gpui::App;
+use gpui::SharedString;
 use serde::{Serialize, de::DeserializeOwned};
 use serde_json::Value;
 use std::{ops::Range, sync::LazyLock};
@@ -10,16 +10,10 @@ use util::RangeExt;
 pub struct SettingsJsonSchemaParams<'a> {
     pub language_names: &'a [String],
     pub font_names: &'a [String],
+    pub theme_names: &'a [SharedString],
+    pub icon_theme_names: &'a [SharedString],
 }
 
-/// Value registered which specifies JSON schemas that are generated at runtime.
-pub struct ParameterizedJsonSchema {
-    pub add_and_get_ref:
-        fn(&mut schemars::SchemaGenerator, &SettingsJsonSchemaParams, &App) -> schemars::Schema,
-}
-
-inventory::collect!(ParameterizedJsonSchema);
-
 pub fn update_value_in_json_text<'a>(
     text: &mut String,
     key_path: &mut Vec<&'a str>,

crates/settings/src/settings_store.rs

@@ -10,7 +10,7 @@ use futures::{
 use gpui::{App, AsyncApp, BorrowAppContext, Global, SharedString, Task, UpdateGlobal};
 
 use paths::{EDITORCONFIG_NAME, local_settings_file_relative_path, task_file_name};
-use schemars::JsonSchema;
+use schemars::{JsonSchema, json_schema};
 use serde_json::Value;
 use smallvec::SmallVec;
 use std::{
@@ -18,16 +18,23 @@ use std::{
     fmt::Debug,
     ops::Range,
     path::{Path, PathBuf},
+    rc::Rc,
     str::{self, FromStr},
     sync::Arc,
 };
-use util::{ResultExt as _, schemars::DefaultDenyUnknownFields};
+use util::{
+    ResultExt as _,
+    schemars::{DefaultDenyUnknownFields, replace_subschema},
+};
 
 pub type EditorconfigProperties = ec4rs::Properties;
 
 use crate::{
-    ActiveSettingsProfileName, ParameterizedJsonSchema, SettingsJsonSchemaParams, SettingsUiEntry,
-    VsCodeSettings, WorktreeId, parse_json_with_comments, replace_value_in_json_text,
+    ActiveSettingsProfileName, FontFamilyName, IconThemeName, LanguageSettingsContent,
+    LanguageToSettingsMap, SettingsJsonSchemaParams, SettingsUiEntry, ThemeName, VsCodeSettings,
+    WorktreeId,
+    merge_from::MergeFrom,
+    parse_json_with_comments, replace_value_in_json_text,
     settings_content::{
         ExtensionsSettingsContent, ProjectSettingsContent, ServerSettingsContent, SettingsContent,
         UserSettingsContent,
@@ -58,15 +65,10 @@ pub trait Settings: 'static + Send + Sync + Sized {
     const PRESERVED_KEYS: Option<&'static [&'static str]> = None;
 
     /// Read the value from default.json.
+    ///
     /// This function *should* panic if default values are missing,
     /// and you should add a default to default.json for documentation.
-    fn from_defaults(content: &SettingsContent, cx: &mut App) -> Self;
-
-    /// Update the value based on the content from the current file.
-    ///
-    /// This function *should not* panic if there are problems, as the
-    /// content of user-provided settings files may be incomplete or invalid.
-    fn refine(&mut self, content: &SettingsContent, cx: &mut App);
+    fn from_settings(content: &SettingsContent, cx: &mut App) -> Self;
 
     fn missing_default() -> anyhow::Error {
         anyhow::anyhow!("missing default for: {}", std::any::type_name::<Self>())
@@ -140,12 +142,15 @@ pub struct SettingsLocation<'a> {
 /// A set of strongly-typed setting values defined via multiple config files.
 pub struct SettingsStore {
     setting_values: HashMap<TypeId, Box<dyn AnySettingValue>>,
-    default_settings: Box<SettingsContent>,
+    default_settings: Rc<SettingsContent>,
     user_settings: Option<UserSettingsContent>,
     global_settings: Option<Box<SettingsContent>>,
 
     extension_settings: Option<Box<SettingsContent>>,
     server_settings: Option<Box<SettingsContent>>,
+
+    merged_settings: Rc<SettingsContent>,
+
     local_settings: BTreeMap<(WorktreeId, Arc<Path>), SettingsContent>,
     raw_editorconfig_settings: BTreeMap<(WorktreeId, Arc<Path>), (String, Option<Editorconfig>)>,
 
@@ -193,8 +198,7 @@ struct SettingValue<T> {
 trait AnySettingValue: 'static + Send + Sync {
     fn setting_type_name(&self) -> &'static str;
 
-    fn from_default(&self, s: &SettingsContent, cx: &mut App) -> Box<dyn Any>;
-    fn refine(&self, value: &mut dyn Any, s: &[&SettingsContent], cx: &mut App);
+    fn from_settings(&self, s: &SettingsContent, cx: &mut App) -> Box<dyn Any>;
 
     fn value_for_path(&self, path: Option<SettingsLocation>) -> &dyn Any;
     fn all_local_values(&self) -> Vec<(WorktreeId, Arc<Path>, &dyn Any)>;
@@ -210,14 +214,17 @@ trait AnySettingValue: 'static + Send + Sync {
 impl SettingsStore {
     pub fn new(cx: &App, default_settings: &str) -> Self {
         let (setting_file_updates_tx, mut setting_file_updates_rx) = mpsc::unbounded();
-        let default_settings = parse_json_with_comments(default_settings).unwrap();
+        let default_settings: Rc<SettingsContent> =
+            parse_json_with_comments(default_settings).unwrap();
         Self {
             setting_values: Default::default(),
-            default_settings,
+            default_settings: default_settings.clone(),
             global_settings: None,
             server_settings: None,
             user_settings: None,
             extension_settings: None,
+
+            merged_settings: default_settings,
             local_settings: BTreeMap::default(),
             raw_editorconfig_settings: BTreeMap::default(),
             setting_file_updates_tx,
@@ -257,38 +264,7 @@ impl SettingsStore {
             global_value: None,
             local_values: Vec::new(),
         }));
-
-        let mut refinements = Vec::default();
-
-        if let Some(extension_settings) = self.extension_settings.as_deref() {
-            refinements.push(extension_settings)
-        }
-
-        if let Some(global_settings) = self.global_settings.as_deref() {
-            refinements.push(global_settings)
-        }
-
-        if let Some(user_settings) = self.user_settings.as_ref() {
-            refinements.push(&user_settings.content);
-            if let Some(release_channel) = user_settings.for_release_channel() {
-                refinements.push(release_channel)
-            }
-            if let Some(os) = user_settings.for_os() {
-                refinements.push(os)
-            }
-            if let Some(profile) = user_settings.for_profile(cx) {
-                refinements.push(profile)
-            }
-        }
-
-        if let Some(server_settings) = self.server_settings.as_ref() {
-            refinements.push(server_settings)
-        }
-        let mut value = T::from_defaults(&self.default_settings, cx);
-        for refinement in refinements {
-            value.refine(refinement, cx)
-        }
-
+        let value = T::from_settings(&self.merged_settings, cx);
         setting_value.set_global_value(Box::new(value));
     }
 
@@ -831,19 +807,56 @@ impl SettingsStore {
             })
     }
 
-    pub fn json_schema(&self, schema_params: &SettingsJsonSchemaParams, cx: &App) -> Value {
+    pub fn json_schema(&self, params: &SettingsJsonSchemaParams) -> Value {
         let mut generator = schemars::generate::SchemaSettings::draft2019_09()
             .with_transform(DefaultDenyUnknownFields)
             .into_generator();
 
-        let schema = UserSettingsContent::json_schema(&mut generator);
+        UserSettingsContent::json_schema(&mut generator);
 
-        // add schemas which are determined at runtime
-        for parameterized_json_schema in inventory::iter::<ParameterizedJsonSchema>() {
-            (parameterized_json_schema.add_and_get_ref)(&mut generator, schema_params, cx);
-        }
+        let language_settings_content_ref = generator
+            .subschema_for::<LanguageSettingsContent>()
+            .to_value();
+        replace_subschema::<LanguageToSettingsMap>(&mut generator, || {
+            json_schema!({
+                "type": "object",
+                "properties": params
+                    .language_names
+                    .iter()
+                    .map(|name| {
+                        (
+                            name.clone(),
+                            language_settings_content_ref.clone(),
+                        )
+                    })
+                    .collect::<serde_json::Map<_, _>>()
+            })
+        });
 
-        schema.to_value()
+        replace_subschema::<FontFamilyName>(&mut generator, || {
+            json_schema!({
+                "type": "string",
+                "enum": params.font_names,
+            })
+        });
+
+        replace_subschema::<ThemeName>(&mut generator, || {
+            json_schema!({
+                "type": "string",
+                "enum": params.theme_names,
+            })
+        });
+
+        replace_subschema::<IconThemeName>(&mut generator, || {
+            json_schema!({
+                "type": "string",
+                "enum": params.icon_theme_names,
+            })
+        });
+
+        generator
+            .root_schema_for::<UserSettingsContent>()
+            .to_value()
     }
 
     fn recompute_values(
@@ -852,74 +865,62 @@ impl SettingsStore {
         cx: &mut App,
     ) -> std::result::Result<(), InvalidSettingsError> {
         // Reload the global and local values for every setting.
-        let mut project_settings_stack = Vec::<&SettingsContent>::new();
+        let mut project_settings_stack = Vec::<SettingsContent>::new();
         let mut paths_stack = Vec::<Option<(WorktreeId, &Path)>>::new();
 
-        let mut refinements = Vec::default();
-
-        if let Some(extension_settings) = self.extension_settings.as_deref() {
-            refinements.push(extension_settings)
-        }
-
-        if let Some(global_settings) = self.global_settings.as_deref() {
-            refinements.push(global_settings)
-        }
-
-        if let Some(user_settings) = self.user_settings.as_ref() {
-            refinements.push(&user_settings.content);
-            if let Some(release_channel) = user_settings.for_release_channel() {
-                refinements.push(release_channel)
+        if changed_local_path.is_none() {
+            let mut merged = self.default_settings.as_ref().clone();
+            merged.merge_from(self.extension_settings.as_deref());
+            merged.merge_from(self.global_settings.as_deref());
+            if let Some(user_settings) = self.user_settings.as_ref() {
+                merged.merge_from(Some(&user_settings.content));
+                merged.merge_from(user_settings.for_release_channel());
+                merged.merge_from(user_settings.for_os());
+                merged.merge_from(user_settings.for_profile(cx));
             }
-            if let Some(os) = user_settings.for_os() {
-                refinements.push(os)
-            }
-            if let Some(profile) = user_settings.for_profile(cx) {
-                refinements.push(profile)
-            }
-        }
+            merged.merge_from(self.server_settings.as_deref());
+            self.merged_settings = Rc::new(merged);
 
-        if let Some(server_settings) = self.server_settings.as_ref() {
-            refinements.push(server_settings)
-        }
-
-        for setting_value in self.setting_values.values_mut() {
-            // If the global settings file changed, reload the global value for the field.
-            if changed_local_path.is_none() {
-                let mut value = setting_value.from_default(&self.default_settings, cx);
-                setting_value.refine(value.as_mut(), &refinements, cx);
+            for setting_value in self.setting_values.values_mut() {
+                let value = setting_value.from_settings(&self.merged_settings, cx);
                 setting_value.set_global_value(value);
             }
+        }
 
-            // Reload the local values for the setting.
-            paths_stack.clear();
-            project_settings_stack.clear();
-            for ((root_id, directory_path), local_settings) in &self.local_settings {
-                // Build a stack of all of the local values for that setting.
-                while let Some(prev_entry) = paths_stack.last() {
-                    if let Some((prev_root_id, prev_path)) = prev_entry
-                        && (root_id != prev_root_id || !directory_path.starts_with(prev_path))
-                    {
-                        paths_stack.pop();
-                        project_settings_stack.pop();
-                        continue;
-                    }
-                    break;
-                }
-
-                paths_stack.push(Some((*root_id, directory_path.as_ref())));
-                project_settings_stack.push(local_settings);
-
-                // If a local settings file changed, then avoid recomputing local
-                // settings for any path outside of that directory.
-                if changed_local_path.is_some_and(|(changed_root_id, changed_local_path)| {
-                    *root_id != changed_root_id || !directory_path.starts_with(changed_local_path)
-                }) {
+        for ((root_id, directory_path), local_settings) in &self.local_settings {
+            // Build a stack of all of the local values for that setting.
+            while let Some(prev_entry) = paths_stack.last() {
+                if let Some((prev_root_id, prev_path)) = prev_entry
+                    && (root_id != prev_root_id || !directory_path.starts_with(prev_path))
+                {
+                    paths_stack.pop();
+                    project_settings_stack.pop();
                     continue;
                 }
+                break;
+            }
 
-                let mut value = setting_value.from_default(&self.default_settings, cx);
-                setting_value.refine(value.as_mut(), &refinements, cx);
-                setting_value.refine(value.as_mut(), &project_settings_stack, cx);
+            paths_stack.push(Some((*root_id, directory_path.as_ref())));
+            let mut merged_local_settings = if let Some(deepest) = project_settings_stack.last() {
+                (*deepest).clone()
+            } else {
+                self.merged_settings.as_ref().clone()
+            };
+            merged_local_settings.merge_from(Some(local_settings));
+
+            project_settings_stack.push(merged_local_settings);
+
+            // If a local settings file changed, then avoid recomputing local
+            // settings for any path outside of that directory.
+            if changed_local_path.is_some_and(|(changed_root_id, changed_local_path)| {
+                *root_id != changed_root_id || !directory_path.starts_with(changed_local_path)
+            }) {
+                continue;
+            }
+
+            for setting_value in self.setting_values.values_mut() {
+                let value =
+                    setting_value.from_settings(&project_settings_stack.last().unwrap(), cx);
                 setting_value.set_local_value(*root_id, directory_path.clone(), value);
             }
         }
@@ -1001,15 +1002,8 @@ impl Debug for SettingsStore {
 }
 
 impl<T: Settings> AnySettingValue for SettingValue<T> {
-    fn from_default(&self, s: &SettingsContent, cx: &mut App) -> Box<dyn Any> {
-        Box::new(T::from_defaults(s, cx)) as _
-    }
-
-    fn refine(&self, value: &mut dyn Any, refinements: &[&SettingsContent], cx: &mut App) {
-        let value = value.downcast_mut::<T>().unwrap();
-        for refinement in refinements {
-            value.refine(refinement, cx)
-        }
+    fn from_settings(&self, s: &SettingsContent, cx: &mut App) -> Box<dyn Any> {
+        Box::new(T::from_settings(s, cx)) as _
     }
 
     fn setting_type_name(&self) -> &'static str {
@@ -1072,7 +1066,6 @@ mod tests {
 
     use super::*;
     use unindent::Unindent;
-    use util::MergeFrom;
 
     #[derive(Debug, PartialEq)]
     struct AutoUpdateSetting {
@@ -1080,19 +1073,11 @@ mod tests {
     }
 
     impl Settings for AutoUpdateSetting {
-        fn from_defaults(content: &SettingsContent, _: &mut App) -> Self {
+        fn from_settings(content: &SettingsContent, _: &mut App) -> Self {
             AutoUpdateSetting {
                 auto_update: content.auto_update.unwrap(),
             }
         }
-
-        fn refine(&mut self, content: &SettingsContent, _: &mut App) {
-            if let Some(auto_update) = content.auto_update {
-                self.auto_update = auto_update;
-            }
-        }
-
-        fn import_from_vscode(_: &VsCodeSettings, _: &mut SettingsContent) {}
     }
 
     #[derive(Debug, PartialEq)]
@@ -1102,7 +1087,7 @@ mod tests {
     }
 
     impl Settings for TitleBarSettings {
-        fn from_defaults(content: &SettingsContent, _: &mut App) -> Self {
+        fn from_settings(content: &SettingsContent, _: &mut App) -> Self {
             let content = content.title_bar.clone().unwrap();
             TitleBarSettings {
                 show: content.show.unwrap(),
@@ -1110,13 +1095,6 @@ mod tests {
             }
         }
 
-        fn refine(&mut self, content: &SettingsContent, _: &mut App) {
-            let Some(content) = content.title_bar.as_ref() else {
-                return;
-            };
-            self.show.merge_from(&content.show)
-        }
-
         fn import_from_vscode(vscode: &VsCodeSettings, content: &mut SettingsContent) {
             let mut show = None;
 
@@ -1138,7 +1116,7 @@ mod tests {
     }
 
     impl Settings for DefaultLanguageSettings {
-        fn from_defaults(content: &SettingsContent, _: &mut App) -> Self {
+        fn from_settings(content: &SettingsContent, _: &mut App) -> Self {
             let content = &content.project.all_languages.defaults;
             DefaultLanguageSettings {
                 tab_size: content.tab_size.unwrap(),
@@ -1146,13 +1124,6 @@ mod tests {
             }
         }
 
-        fn refine(&mut self, content: &SettingsContent, _: &mut App) {
-            let content = &content.project.all_languages.defaults;
-            self.tab_size.merge_from(&content.tab_size);
-            self.preferred_line_length
-                .merge_from(&content.preferred_line_length);
-        }
-
         fn import_from_vscode(vscode: &VsCodeSettings, content: &mut SettingsContent) {
             let content = &mut content.project.all_languages.defaults;