Use anyhow more idiomatically (#31052)

https://github.com/zed-industries/zed/issues/30972 brought up another
case where our context is not enough to track the actual source of the
issue: we get a general top-level error without inner error.

The reason for this was `.ok_or_else(|| anyhow!("failed to read HEAD
SHA"))?; ` on the top level.

The PR finally reworks the way we use anyhow to reduce such issues (or
at least make it simpler to bubble them up later in a fix).
On top of that, uses a few more anyhow methods for better readability.

* `.ok_or_else(|| anyhow!("..."))`, `map_err` and other similar error
conversion/option reporting cases are replaced with `context` and
`with_context` calls
* in addition to that, various `anyhow!("failed to do ...")` are
stripped with `.context("Doing ...")` messages instead to remove the
parasitic `failed to` text
* `anyhow::ensure!` is used instead of `if ... { return Err(...); }`
calls
* `anyhow::bail!` is used instead of `return Err(anyhow!(...));`

Release Notes:

- N/A

crates/gpui/src/platform/blade/blade_context.rs

@@ -30,7 +30,7 @@ impl BladeContext {
                     ..Default::default()
                 })
             }
-            .map_err(|e| anyhow::anyhow!("{:?}", e))?,
+            .map_err(|e| anyhow::anyhow!("{e:?}"))?,
         );
         Ok(Self { gpu })
     }
@@ -49,8 +49,7 @@ fn parse_pci_id(id: &str) -> anyhow::Result<u32> {
         "Expected a 4 digit PCI ID in hexadecimal format"
     );
 
-    return u32::from_str_radix(id, 16)
-        .map_err(|_| anyhow::anyhow!("Failed to parse PCI ID as hex"));
+    return u32::from_str_radix(id, 16).context("parsing PCI ID as hex");
 }
 
 #[cfg(test)]

crates/gpui/src/platform/linux/headless/client.rs

@@ -95,9 +95,7 @@ impl LinuxClient for HeadlessClient {
         _handle: AnyWindowHandle,
         _params: WindowParams,
     ) -> anyhow::Result<Box<dyn PlatformWindow>> {
-        Err(anyhow::anyhow!(
-            "neither DISPLAY nor WAYLAND_DISPLAY is set. You can run in headless mode"
-        ))
+        anyhow::bail!("neither DISPLAY nor WAYLAND_DISPLAY is set. You can run in headless mode");
     }
 
     fn compositor_name(&self) -> &'static str {

crates/gpui/src/platform/linux/platform.rs

@@ -490,7 +490,7 @@ impl<P: LinuxClient + 'static> Platform for P {
                     let attributes = item.attributes().await?;
                     let username = attributes
                         .get("username")
-                        .ok_or_else(|| anyhow!("Cannot find username in stored credentials"))?;
+                        .context("Cannot find username in stored credentials")?;
                     let secret = item.secret().await?;
 
                     // we lose the zeroizing capabilities at this boundary,

crates/gpui/src/platform/linux/text_system.rs

@@ -3,7 +3,7 @@ use crate::{
     GlyphId, LineLayout, Pixels, PlatformTextSystem, Point, RenderGlyphParams, SUBPIXEL_VARIANTS,
     ShapedGlyph, ShapedRun, SharedString, Size, point, size,
 };
-use anyhow::{Context as _, Ok, Result, anyhow};
+use anyhow::{Context as _, Ok, Result};
 use collections::HashMap;
 use cosmic_text::{
     Attrs, AttrsList, CacheKey, Family, Font as CosmicTextFont, FontFeatures as CosmicFontFeatures,
@@ -232,7 +232,7 @@ impl CosmicTextSystemState {
             let font = self
                 .font_system
                 .get_font(font_id)
-                .ok_or_else(|| anyhow!("Could not load font"))?;
+                .context("Could not load font")?;
 
             // HACK: To let the storybook run and render Windows caption icons. We should actually do better font fallback.
             let allowed_bad_font_names = [
@@ -309,7 +309,7 @@ impl CosmicTextSystemState {
         glyph_bounds: Bounds<DevicePixels>,
     ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
         if glyph_bounds.size.width.0 == 0 || glyph_bounds.size.height.0 == 0 {
-            Err(anyhow!("glyph bounds are empty"))
+            anyhow::bail!("glyph bounds are empty");
         } else {
             let bitmap_size = glyph_bounds.size;
             let font = &self.loaded_fonts[params.font_id.0].font;
@@ -469,7 +469,7 @@ impl TryFrom<&FontFeatures> for CosmicFontFeatures {
                 .0
                 .as_bytes()
                 .try_into()
-                .map_err(|_| anyhow!("Incorrect feature flag format"))?;
+                .context("Incorrect feature flag format")?;
 
             let tag = cosmic_text::FeatureTag::new(&name_bytes);
 

crates/gpui/src/platform/linux/wayland/display.rs

@@ -3,6 +3,7 @@ use std::{
     hash::{Hash, Hasher},
 };
 
+use anyhow::Context as _;
 use uuid::Uuid;
 use wayland_backend::client::ObjectId;
 
@@ -28,11 +29,11 @@ impl PlatformDisplay for WaylandDisplay {
     }
 
     fn uuid(&self) -> anyhow::Result<Uuid> {
-        if let Some(name) = &self.name {
-            Ok(Uuid::new_v5(&Uuid::NAMESPACE_DNS, name.as_bytes()))
-        } else {
-            Err(anyhow::anyhow!("Wayland display does not have a name"))
-        }
+        let name = self
+            .name
+            .as_ref()
+            .context("Wayland display does not have a name")?;
+        Ok(Uuid::new_v5(&Uuid::NAMESPACE_DNS, name.as_bytes()))
     }
 
     fn bounds(&self) -> Bounds<Pixels> {

crates/gpui/src/platform/linux/x11/display.rs

@@ -1,4 +1,4 @@
-use anyhow::Result;
+use anyhow::Context as _;
 use uuid::Uuid;
 use x11rb::{connection::Connection as _, xcb_ffi::XCBConnection};
 
@@ -17,12 +17,11 @@ impl X11Display {
         scale_factor: f32,
         x_screen_index: usize,
     ) -> anyhow::Result<Self> {
-        let Some(screen) = xcb.setup().roots.get(x_screen_index) else {
-            return Err(anyhow::anyhow!(
-                "No screen found with index {}",
-                x_screen_index
-            ));
-        };
+        let screen = xcb
+            .setup()
+            .roots
+            .get(x_screen_index)
+            .with_context(|| format!("No screen found with index {x_screen_index}"))?;
         Ok(Self {
             x_screen_index,
             bounds: Bounds {
@@ -42,7 +41,7 @@ impl PlatformDisplay for X11Display {
         DisplayId(self.x_screen_index as u32)
     }
 
-    fn uuid(&self) -> Result<Uuid> {
+    fn uuid(&self) -> anyhow::Result<Uuid> {
         Ok(self.uuid)
     }
 

crates/gpui/src/platform/mac/metal_atlas.rs

@@ -2,7 +2,7 @@ use crate::{
     AtlasKey, AtlasTextureId, AtlasTextureKind, AtlasTile, Bounds, DevicePixels, PlatformAtlas,
     Point, Size, platform::AtlasTextureList,
 };
-use anyhow::{Result, anyhow};
+use anyhow::{Context as _, Result};
 use collections::FxHashMap;
 use derive_more::{Deref, DerefMut};
 use etagere::BucketedAtlasAllocator;
@@ -77,7 +77,7 @@ impl PlatformAtlas for MetalAtlas {
             };
             let tile = lock
                 .allocate(size, key.texture_kind())
-                .ok_or_else(|| anyhow!("failed to allocate"))?;
+                .context("failed to allocate")?;
             let texture = lock.texture(tile.texture_id);
             texture.upload(tile.bounds, &bytes);
             lock.tiles_by_key.insert(key.clone(), tile.clone());

crates/gpui/src/platform/mac/metal_renderer.rs

@@ -4,7 +4,7 @@ use crate::{
     MonochromeSprite, PaintSurface, Path, PathId, PathVertex, PolychromeSprite, PrimitiveBatch,
     Quad, ScaledPixels, Scene, Shadow, Size, Surface, Underline, point, size,
 };
-use anyhow::{Result, anyhow};
+use anyhow::{Context as _, Result};
 use block::ConcreteBlock;
 use cocoa::{
     base::{NO, YES},
@@ -376,14 +376,14 @@ impl MetalRenderer {
         let command_buffer = command_queue.new_command_buffer();
         let mut instance_offset = 0;
 
-        let Some(path_tiles) = self.rasterize_paths(
-            scene.paths(),
-            instance_buffer,
-            &mut instance_offset,
-            command_buffer,
-        ) else {
-            return Err(anyhow!("failed to rasterize {} paths", scene.paths().len()));
-        };
+        let path_tiles = self
+            .rasterize_paths(
+                scene.paths(),
+                instance_buffer,
+                &mut instance_offset,
+                command_buffer,
+            )
+            .with_context(|| format!("rasterizing {} paths", scene.paths().len()))?;
 
         let render_pass_descriptor = metal::RenderPassDescriptor::new();
         let color_attachment = render_pass_descriptor
@@ -471,7 +471,7 @@ impl MetalRenderer {
 
             if !ok {
                 command_encoder.end_encoding();
-                return Err(anyhow!(
+                anyhow::bail!(
                     "scene too large: {} paths, {} shadows, {} quads, {} underlines, {} mono, {} poly, {} surfaces",
                     scene.paths.len(),
                     scene.shadows.len(),
@@ -480,7 +480,7 @@ impl MetalRenderer {
                     scene.monochrome_sprites.len(),
                     scene.polychrome_sprites.len(),
                     scene.surfaces.len(),
-                ));
+                );
             }
         }
 

crates/gpui/src/platform/mac/platform.rs

@@ -638,7 +638,7 @@ impl Platform for MacPlatform {
                     Ok(())
                 } else {
                     let msg: id = msg_send![error, localizedDescription];
-                    Err(anyhow!("Failed to register: {:?}", msg))
+                    Err(anyhow!("Failed to register: {msg:?}"))
                 };
 
                 if let Some(done_tx) = done_tx.take() {
@@ -832,11 +832,8 @@ impl Platform for MacPlatform {
     fn app_path(&self) -> Result<PathBuf> {
         unsafe {
             let bundle: id = NSBundle::mainBundle();
-            if bundle.is_null() {
-                Err(anyhow!("app is not running inside a bundle"))
-            } else {
-                Ok(path_from_objc(msg_send![bundle, bundlePath]))
-            }
+            anyhow::ensure!(!bundle.is_null(), "app is not running inside a bundle");
+            Ok(path_from_objc(msg_send![bundle, bundlePath]))
         }
     }
 
@@ -877,17 +874,11 @@ impl Platform for MacPlatform {
     fn path_for_auxiliary_executable(&self, name: &str) -> Result<PathBuf> {
         unsafe {
             let bundle: id = NSBundle::mainBundle();
-            if bundle.is_null() {
-                Err(anyhow!("app is not running inside a bundle"))
-            } else {
-                let name = ns_string(name);
-                let url: id = msg_send![bundle, URLForAuxiliaryExecutable: name];
-                if url.is_null() {
-                    Err(anyhow!("resource not found"))
-                } else {
-                    ns_url_to_path(url)
-                }
-            }
+            anyhow::ensure!(!bundle.is_null(), "app is not running inside a bundle");
+            let name = ns_string(name);
+            let url: id = msg_send![bundle, URLForAuxiliaryExecutable: name];
+            anyhow::ensure!(!url.is_null(), "resource not found");
+            ns_url_to_path(url)
         }
     }
 
@@ -1101,10 +1092,7 @@ impl Platform for MacPlatform {
                     verb = "creating";
                     status = SecItemAdd(attrs.as_concrete_TypeRef(), ptr::null_mut());
                 }
-
-                if status != errSecSuccess {
-                    return Err(anyhow!("{} password failed: {}", verb, status));
-                }
+                anyhow::ensure!(status == errSecSuccess, "{verb} password failed: {status}");
             }
             Ok(())
         })
@@ -1131,24 +1119,24 @@ impl Platform for MacPlatform {
                 match status {
                     security::errSecSuccess => {}
                     security::errSecItemNotFound | security::errSecUserCanceled => return Ok(None),
-                    _ => return Err(anyhow!("reading password failed: {}", status)),
+                    _ => anyhow::bail!("reading password failed: {status}"),
                 }
 
                 let result = CFType::wrap_under_create_rule(result)
                     .downcast::<CFDictionary>()
-                    .ok_or_else(|| anyhow!("keychain item was not a dictionary"))?;
+                    .context("keychain item was not a dictionary")?;
                 let username = result
                     .find(kSecAttrAccount as *const _)
-                    .ok_or_else(|| anyhow!("account was missing from keychain item"))?;
+                    .context("account was missing from keychain item")?;
                 let username = CFType::wrap_under_get_rule(*username)
                     .downcast::<CFString>()
-                    .ok_or_else(|| anyhow!("account was not a string"))?;
+                    .context("account was not a string")?;
                 let password = result
                     .find(kSecValueData as *const _)
-                    .ok_or_else(|| anyhow!("password was missing from keychain item"))?;
+                    .context("password was missing from keychain item")?;
                 let password = CFType::wrap_under_get_rule(*password)
                     .downcast::<CFData>()
-                    .ok_or_else(|| anyhow!("password was not a string"))?;
+                    .context("password was not a string")?;
 
                 Ok(Some((username.to_string(), password.bytes().to_vec())))
             }
@@ -1168,10 +1156,7 @@ impl Platform for MacPlatform {
                 query_attrs.set(kSecAttrServer as *const _, url.as_CFTypeRef());
 
                 let status = SecItemDelete(query_attrs.as_concrete_TypeRef());
-
-                if status != errSecSuccess {
-                    return Err(anyhow!("delete password failed: {}", status));
-                }
+                anyhow::ensure!(status == errSecSuccess, "delete password failed: {status}");
             }
             Ok(())
         })
@@ -1455,15 +1440,12 @@ unsafe fn ns_string(string: &str) -> id {
 
 unsafe fn ns_url_to_path(url: id) -> Result<PathBuf> {
     let path: *mut c_char = msg_send![url, fileSystemRepresentation];
-    if path.is_null() {
-        Err(anyhow!("url is not a file path: {}", unsafe {
-            CStr::from_ptr(url.absoluteString().UTF8String()).to_string_lossy()
-        }))
-    } else {
-        Ok(PathBuf::from(OsStr::from_bytes(unsafe {
-            CStr::from_ptr(path).to_bytes()
-        })))
-    }
+    anyhow::ensure!(!path.is_null(), "url is not a file path: {}", unsafe {
+        CStr::from_ptr(url.absoluteString().UTF8String()).to_string_lossy()
+    });
+    Ok(PathBuf::from(OsStr::from_bytes(unsafe {
+        CStr::from_ptr(path).to_bytes()
+    })))
 }
 
 #[link(name = "Carbon", kind = "framework")]

crates/gpui/src/platform/mac/text_system.rs

@@ -194,7 +194,7 @@ impl MacTextSystemState {
                         core_graphics::data_provider::CGDataProvider::from_slice(embedded_font)
                     };
                     let font = core_graphics::font::CGFont::from_data_provider(data_provider)
-                        .map_err(|_| anyhow!("Could not load an embedded font."))?;
+                        .map_err(|()| anyhow!("Could not load an embedded font."))?;
                     let font = font_kit::loaders::core_text::Font::from_core_graphics_font(font);
                     Ok(Handle::from_native(&font))
                 }
@@ -348,7 +348,7 @@ impl MacTextSystemState {
         glyph_bounds: Bounds<DevicePixels>,
     ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
         if glyph_bounds.size.width.0 == 0 || glyph_bounds.size.height.0 == 0 {
-            Err(anyhow!("glyph bounds are empty"))
+            anyhow::bail!("glyph bounds are empty");
         } else {
             // Add an extra pixel when the subpixel variant isn't zero to make room for anti-aliasing.
             let mut bitmap_size = glyph_bounds.size;

crates/gpui/src/platform/windows/destination_list.rs

@@ -54,9 +54,7 @@ impl DockMenuItem {
                 },
                 action,
             }),
-            _ => Err(anyhow::anyhow!(
-                "Only `MenuItem::Action` is supported for dock menu on Windows."
-            )),
+            _ => anyhow::bail!("Only `MenuItem::Action` is supported for dock menu on Windows."),
         }
     }
 }

crates/gpui/src/platform/windows/direct_write.rs

@@ -1,7 +1,7 @@
 use std::{borrow::Cow, sync::Arc};
 
 use ::util::ResultExt;
-use anyhow::{Result, anyhow};
+use anyhow::Result;
 use collections::HashMap;
 use itertools::Itertools;
 use parking_lot::{RwLock, RwLockUpgradableReadGuard};
@@ -729,7 +729,7 @@ impl DirectWriteState {
         glyph_bounds: Bounds<DevicePixels>,
     ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
         if glyph_bounds.size.width.0 == 0 || glyph_bounds.size.height.0 == 0 {
-            return Err(anyhow!("glyph bounds are empty"));
+            anyhow::bail!("glyph bounds are empty");
         }
 
         let font_info = &self.fonts[params.font_id.0];
@@ -1301,7 +1301,7 @@ fn get_postscript_name(font_face: &IDWriteFontFace3, locale: &str) -> Result<Str
         )?
     };
     if !exists.as_bool() || info.is_none() {
-        return Err(anyhow!("No postscript name found for font face"));
+        anyhow::bail!("No postscript name found for font face");
     }
 
     get_name(info.unwrap(), locale)
@@ -1393,9 +1393,7 @@ fn get_name(string: IDWriteLocalizedStrings, locale: &str) -> Result<String> {
                 &mut exists as _,
             )?
         };
-        if !exists.as_bool() {
-            return Err(anyhow!("No localised string for {}", locale));
-        }
+        anyhow::ensure!(exists.as_bool(), "No localised string for {locale}");
     }
 
     let name_length = unsafe { string.GetStringLength(locale_name_index) }? as usize;

crates/gpui/src/platform/windows/platform.rs

@@ -576,7 +576,7 @@ impl Platform for WindowsPlatform {
 
     // todo(windows)
     fn path_for_auxiliary_executable(&self, _name: &str) -> Result<PathBuf> {
-        Err(anyhow!("not yet implemented"))
+        anyhow::bail!("not yet implemented");
     }
 
     fn set_cursor_style(&self, style: CursorStyle) {