migrator: In-memory migration and improved UX (#24621)

This PR adds:

- Support for deprecated keymap and settings (In-memory migration)
- Migration prompt only shown in `settings.json` / `keymap.json`.

Release Notes:

- The migration banner will only appear in `settings.json` and
`keymap.json` if you have deprecated settings or keybindings, allowing
you to migrate them to work with the new version on Zed.

crates/settings/src/keymap_file.rs

@@ -10,7 +10,7 @@ use schemars::{
     schema::{ArrayValidation, InstanceType, Schema, SchemaObject, SubschemaValidation},
     JsonSchema,
 };
-use serde::{Deserialize, Serialize};
+use serde::Deserialize;
 use serde_json::Value;
 use std::{any::TypeId, fmt::Write, rc::Rc, sync::Arc, sync::LazyLock};
 use util::{asset_str, markdown::MarkdownString};
@@ -47,12 +47,12 @@ pub(crate) static KEY_BINDING_VALIDATORS: LazyLock<BTreeMap<TypeId, Box<dyn KeyB
 
 /// Keymap configuration consisting of sections. Each section may have a context predicate which
 /// determines whether its bindings are used.
-#[derive(Debug, Deserialize, Default, Clone, JsonSchema, Serialize)]
+#[derive(Debug, Deserialize, Default, Clone, JsonSchema)]
 #[serde(transparent)]
 pub struct KeymapFile(Vec<KeymapSection>);
 
 /// Keymap section which binds keystrokes to actions.
-#[derive(Debug, Deserialize, Default, Clone, JsonSchema, Serialize)]
+#[derive(Debug, Deserialize, Default, Clone, JsonSchema)]
 pub struct KeymapSection {
     /// Determines when these bindings are active. When just a name is provided, like `Editor` or
     /// `Workspace`, the bindings will be active in that context. Boolean expressions like `X && Y`,
@@ -97,9 +97,9 @@ impl KeymapSection {
 /// Unlike the other json types involved in keymaps (including actions), this doc-comment will not
 /// be included in the generated JSON schema, as it manually defines its `JsonSchema` impl. The
 /// actual schema used for it is automatically generated in `KeymapFile::generate_json_schema`.
-#[derive(Debug, Deserialize, Default, Clone, Serialize)]
+#[derive(Debug, Deserialize, Default, Clone)]
 #[serde(transparent)]
-pub struct KeymapAction(pub(crate) Value);
+pub struct KeymapAction(Value);
 
 impl std::fmt::Display for KeymapAction {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
@@ -133,11 +133,9 @@ impl JsonSchema for KeymapAction {
 pub enum KeymapFileLoadResult {
     Success {
         key_bindings: Vec<KeyBinding>,
-        keymap_file: KeymapFile,
     },
     SomeFailedToLoad {
         key_bindings: Vec<KeyBinding>,
-        keymap_file: KeymapFile,
         error_message: MarkdownString,
     },
     JsonParseFailure {
@@ -152,7 +150,7 @@ impl KeymapFile {
 
     pub fn load_asset(asset_path: &str, cx: &App) -> anyhow::Result<Vec<KeyBinding>> {
         match Self::load(asset_str::<SettingsAssets>(asset_path).as_ref(), cx) {
-            KeymapFileLoadResult::Success { key_bindings, .. } => Ok(key_bindings),
+            KeymapFileLoadResult::Success { key_bindings } => Ok(key_bindings),
             KeymapFileLoadResult::SomeFailedToLoad { error_message, .. } => Err(anyhow!(
                 "Error loading built-in keymap \"{asset_path}\": {error_message}"
             )),
@@ -202,7 +200,6 @@ impl KeymapFile {
         if content.is_empty() {
             return KeymapFileLoadResult::Success {
                 key_bindings: Vec::new(),
-                keymap_file: KeymapFile(Vec::new()),
             };
         }
         let keymap_file = match parse_json_with_comments::<Self>(content) {
@@ -296,10 +293,7 @@ impl KeymapFile {
         }
 
         if errors.is_empty() {
-            KeymapFileLoadResult::Success {
-                key_bindings,
-                keymap_file,
-            }
+            KeymapFileLoadResult::Success { key_bindings }
         } else {
             let mut error_message = "Errors in user keymap file.\n".to_owned();
             for (context, section_errors) in errors {
@@ -317,7 +311,6 @@ impl KeymapFile {
             }
             KeymapFileLoadResult::SomeFailedToLoad {
                 key_bindings,
-                keymap_file,
                 error_message: MarkdownString(error_message),
             }
         }
@@ -619,7 +612,7 @@ fn inline_code_string(text: &str) -> MarkdownString {
 
 #[cfg(test)]
 mod tests {
-    use super::KeymapFile;
+    use crate::KeymapFile;
 
     #[test]
     fn can_deserialize_keymap_with_trailing_comma() {

crates/settings/src/settings_file.rs

@@ -1,7 +1,7 @@
 use crate::{settings_store::SettingsStore, Settings};
 use fs::Fs;
 use futures::{channel::mpsc, StreamExt};
-use gpui::{App, BackgroundExecutor, ReadGlobal, UpdateGlobal};
+use gpui::{App, BackgroundExecutor, ReadGlobal};
 use std::{path::PathBuf, sync::Arc, time::Duration};
 
 pub const EMPTY_THEME_NAME: &str = "empty-theme";
@@ -78,40 +78,6 @@ pub fn watch_config_file(
     rx
 }
 
-pub fn handle_settings_file_changes(
-    mut user_settings_file_rx: mpsc::UnboundedReceiver<String>,
-    cx: &mut App,
-    settings_changed: impl Fn(Result<serde_json::Value, anyhow::Error>, &mut App) + 'static,
-) {
-    let user_settings_content = cx
-        .background_executor()
-        .block(user_settings_file_rx.next())
-        .unwrap();
-    SettingsStore::update_global(cx, |store, cx| {
-        let result = store.set_user_settings(&user_settings_content, cx);
-        if let Err(err) = &result {
-            log::error!("Failed to load user settings: {err}");
-        }
-        settings_changed(result, cx);
-    });
-    cx.spawn(move |cx| async move {
-        while let Some(user_settings_content) = user_settings_file_rx.next().await {
-            let result = cx.update_global(|store: &mut SettingsStore, cx| {
-                let result = store.set_user_settings(&user_settings_content, cx);
-                if let Err(err) = &result {
-                    log::error!("Failed to load user settings: {err}");
-                }
-                settings_changed(result, cx);
-                cx.refresh_windows();
-            });
-            if result.is_err() {
-                break; // App dropped
-            }
-        }
-    })
-    .detach();
-}
-
 pub fn update_settings_file<T: Settings>(
     fs: Arc<dyn Fs>,
     cx: &App,