keymap validation: Improve message for action that takes no input (#37877)

See
https://github.com/zed-industries/zed/issues/26370#issuecomment-3200022302

Before (user screenshot):

<img width="650" height="127" alt="Image"
src="https://github.com/user-attachments/assets/9548ce43-657e-46ef-b6be-b95489167ac2"
/>

After (my screenshot):

<img width="616" height="229" alt="image"
src="https://github.com/user-attachments/assets/09028305-e7bb-4a31-bb87-55effbec26f3"
/>

Release Notes:

- N/A

crates/settings/src/keymap_file.rs

@@ -463,8 +463,11 @@ impl KeymapFile {
             add_deprecation(schema, format!("Deprecated, use {new_name}"));
         }
 
-        fn add_description(schema: &mut schemars::Schema, description: String) {
-            schema.insert("description".to_string(), Value::String(description));
+        fn add_description(schema: &mut schemars::Schema, description: &str) {
+            schema.insert(
+                "description".to_string(),
+                Value::String(description.to_string()),
+            );
         }
 
         let empty_object = json_schema!({
@@ -476,32 +479,25 @@ impl KeymapFile {
         //
         // In the case of the array validations, it would even provide an error saying that the name
         // must match the name of the first alternative.
-        let mut plain_action = json_schema!({
+        let mut empty_action_name = json_schema!({
             "type": "string",
             "const": ""
         });
         let no_action_message = "No action named this.";
-        add_description(&mut plain_action, no_action_message.to_owned());
-        add_deprecation(&mut plain_action, no_action_message.to_owned());
-
-        let mut matches_action_name = json_schema!({
-            "const": ""
-        });
-        let no_action_message_input = "No action named this that takes input.";
-        add_description(&mut matches_action_name, no_action_message_input.to_owned());
-        add_deprecation(&mut matches_action_name, no_action_message_input.to_owned());
-
-        let action_with_input = json_schema!({
+        add_description(&mut empty_action_name, no_action_message);
+        add_deprecation(&mut empty_action_name, no_action_message.to_string());
+        let empty_action_name_with_input = json_schema!({
             "type": "array",
             "items": [
-                matches_action_name,
+                empty_action_name,
                 true
             ],
             "minItems": 2,
             "maxItems": 2
         });
-        let mut keymap_action_alternatives = vec![plain_action, action_with_input];
+        let mut keymap_action_alternatives = vec![empty_action_name, empty_action_name_with_input];
 
+        let mut empty_schema_action_names = vec![];
         for (name, action_schema) in action_schemas.into_iter() {
             let description = action_schema.as_ref().and_then(|schema| {
                 schema
@@ -527,8 +523,8 @@ impl KeymapFile {
             } else if let Some(new_name) = deprecation {
                 add_deprecation_preferred_name(&mut plain_action, new_name);
             }
-            if let Some(desc) = description.clone() {
-                add_description(&mut plain_action, desc);
+            if let Some(description) = &description {
+                add_description(&mut plain_action, description);
             }
             keymap_action_alternatives.push(plain_action);
 
@@ -542,8 +538,8 @@ impl KeymapFile {
                 let mut matches_action_name = json_schema!({
                     "const": name
                 });
-                if let Some(desc) = description.clone() {
-                    add_description(&mut matches_action_name, desc);
+                if let Some(description) = &description {
+                    add_description(&mut matches_action_name, description);
                 }
                 if let Some(message) = deprecation_messages.get(name) {
                     add_deprecation(&mut matches_action_name, message.to_string());
@@ -557,9 +553,31 @@ impl KeymapFile {
                     "maxItems": 2
                 });
                 keymap_action_alternatives.push(action_with_input);
+            } else {
+                empty_schema_action_names.push(name);
             }
         }
 
+        if !empty_schema_action_names.is_empty() {
+            let action_names = json_schema!({ "enum": empty_schema_action_names });
+            let no_properties_allowed = json_schema!({
+                "type": "object",
+                "additionalProperties": false
+            });
+            let mut actions_with_empty_input = json_schema!({
+                "type": "array",
+                "items": [action_names, no_properties_allowed],
+                "minItems": 2,
+                "maxItems": 2
+            });
+            add_deprecation(
+                &mut actions_with_empty_input,
+                "This action does not take input - just the action name string should be used."
+                    .to_string(),
+            );
+            keymap_action_alternatives.push(actions_with_empty_input);
+        }
+
         // Placing null first causes json-language-server to default assuming actions should be
         // null, so place it last.
         keymap_action_alternatives.push(json_schema!({

docs/src/vim.md

@@ -490,7 +490,7 @@ Vim mode comes with shortcuts to surround the selection in normal mode (`ys`), b
 {
   "context": "vim_mode == visual",
   "bindings": {
-    "shift-s": ["vim::PushAddSurrounds", {}]
+    "shift-s": "vim::PushAddSurrounds"
   }
 }
 ```