Revert deprecate code actions on format (#40409)

Closes #40334

This reverts the change made in #39983, and includes a replacement
migration that will transform formatter settings values consisting of
only `code_action` format steps into the previously deprecated
`code_actions_on_format` in an attempt to restore the behavior to what
it was before the migration that deprecated `code_actions_on_format`.

This PR will result in a modified order in the `code_actions_on_format`
setting if it existed, however the decision was made to explicitly
ignore this for now, as this PR is primarily targeting users who have
already had the deprecation migration run, and no longer have the
`code_actions_on_format` key

Release Notes:

- Fixed an issue with a settings migration that deprecated the
`code_actions_on_format` setting. The `code_actions_on_format` setting
has been un-deprecated, and affected users will have the bad migration
rolled back with an updated migration

---------

Co-authored-by: Cole Miller <cole@zed.dev>
Co-authored-by: Mikayla Maki <mikayla.c.maki@gmail.com>
Co-authored-by: HactarCE <6060305+HactarCE@users.noreply.github.com>

Author: 4 people

assets/settings/default.json

@@ -1529,6 +1529,7 @@
     // A value of 45 preserves colorful themes while ensuring legibility.
     "minimum_contrast": 45
   },
+  "code_actions_on_format": {},
   // Settings related to running tasks.
   "tasks": {
     "variables": {},
@@ -1698,7 +1699,9 @@
       "preferred_line_length": 72
     },
     "Go": {
-      "formatter": [{ "code_action": "source.organizeImports" }, "language_server"],
+      "code_actions_on_format": {
+        "source.organizeImports": true
+      },
       "debuggers": ["Delve"]
     },
     "GraphQL": {

crates/language/src/language_settings.rs

@@ -142,6 +142,8 @@ pub struct LanguageSettings {
     pub auto_indent_on_paste: bool,
     /// Controls how the editor handles the autoclosed characters.
     pub always_treat_brackets_as_autoclosed: bool,
+    /// Which code actions to run on save
+    pub code_actions_on_format: HashMap<String, bool>,
     /// Whether to perform linked edits
     pub linked_edits: bool,
     /// Task configuration for this language.
@@ -576,6 +578,7 @@ impl settings::Settings for AllLanguageSettings {
                 always_treat_brackets_as_autoclosed: settings
                     .always_treat_brackets_as_autoclosed
                     .unwrap(),
+                code_actions_on_format: settings.code_actions_on_format.unwrap(),
                 linked_edits: settings.linked_edits.unwrap(),
                 tasks: LanguageTaskSettings {
                     variables: tasks.variables.unwrap_or_default(),

crates/migrator/src/migrations.rs

@@ -118,8 +118,8 @@ pub(crate) mod m_2025_10_03 {
     pub(crate) use settings::SETTINGS_PATTERNS;
 }
 
-pub(crate) mod m_2025_10_10 {
+pub(crate) mod m_2025_10_16 {
     mod settings;
 
-    pub(crate) use settings::remove_code_actions_on_format;
+    pub(crate) use settings::restore_code_actions_on_format;
 }

crates/migrator/src/migrations/m_2025_10_10/settings.rs

@@ -0,0 +1,68 @@
+use anyhow::Result;
+use serde_json::Value;
+
+use crate::patterns::migrate_language_setting;
+
+pub fn restore_code_actions_on_format(value: &mut Value) -> Result<()> {
+    migrate_language_setting(value, restore_code_actions_on_format_inner)
+}
+
+fn restore_code_actions_on_format_inner(value: &mut Value, path: &[&str]) -> Result<()> {
+    let Some(obj) = value.as_object_mut() else {
+        return Ok(());
+    };
+    let code_actions_on_format = obj
+        .get("code_actions_on_format")
+        .cloned()
+        .unwrap_or_else(|| Value::Object(Default::default()));
+
+    fn fmt_path(path: &[&str], key: &str) -> String {
+        let mut path = path.to_vec();
+        path.push(key);
+        path.join(".")
+    }
+
+    let Some(mut code_actions_map) = code_actions_on_format.as_object().cloned() else {
+        anyhow::bail!(
+            r#"The `code_actions_on_format` is in an invalid state and cannot be migrated at {}. Please ensure the code_actions_on_format setting is a Map<String, bool>"#,
+            fmt_path(path, "code_actions_on_format"),
+        );
+    };
+
+    let Some(formatter) = obj.get("formatter") else {
+        return Ok(());
+    };
+    let formatter_array = if let Some(array) = formatter.as_array() {
+        array.clone()
+    } else {
+        vec![formatter.clone()]
+    };
+    let mut code_action_formatters = Vec::new();
+    for formatter in formatter_array {
+        let Some(code_action) = formatter.get("code_action") else {
+            return Ok(());
+        };
+        let Some(code_action_name) = code_action.as_str() else {
+            anyhow::bail!(
+                r#"The `code_action` is in an invalid state and cannot be migrated at {}. Please ensure the code_action setting is a String"#,
+                fmt_path(path, "formatter"),
+            );
+        };
+        code_action_formatters.push(code_action_name.to_string());
+    }
+
+    code_actions_map.extend(
+        code_action_formatters
+            .into_iter()
+            .rev()
+            .map(|code_action| (code_action, Value::Bool(true))),
+    );
+
+    obj.remove("formatter");
+    obj.insert(
+        "code_actions_on_format".into(),
+        Value::Object(code_actions_map),
+    );
+
+    Ok(())
+}