fix(configuration): merge inherited overrides

CHANGELOG.md

@@ -86,13 +86,19 @@ our [guidelines for writing a good changelog entry](https://github.com/biomejs/b
 #### Bug fixes
 
 - `biome lint --write` now takes `--only` and `--skip` into account ([#3470](https://github.com/biomejs/biome/issues/3470)). Contributed by @Conaclos
+
 - Fix [#3368](https://github.com/biomejs/biome/issues/3368), now the reporter `github` tracks the diagnostics that belong to formatting and organize imports. Contributed by @ematipico
+
 - Fix [#3545](https://github.com/biomejs/biome/issues/3545), display a warning, 'Avoid using unnecessary Fragment,' when a Fragment contains only one child element that is placed on a new line. Contributed by @satojin219
 
+- Migrating from Prettier or ESLint no longer overwrite the `overrides` field from the configuration ([#3544](https://github.com/biomejs/biome/issues/3544)). Contributed by @Conaclos
+
 ### Configuration
 
-- Add support for loading configuration from `.editorconfig` files ([#1724](https://github.com/biomejs/biome/issues/1724)). Contributed by @dyc3
+- Add support for loading configuration from `.editorconfig` files ([#1724](https://github.com/biomejs/biome/issues/1724)).
+
   Configuration supplied in `.editorconfig` will be overridden by the configuration in `biome.json`. Support is disabled by default and can be enabled by adding the following to your formatter configuration in `biome.json`:
+
   ```json
   {
     "formatter": {
@@ -101,6 +107,58 @@ our [guidelines for writing a good changelog entry](https://github.com/biomejs/b
   }
   ```
 
+  Contributed by @dyc3
+
+- `overrides` from an extended configuration is now merged with the `overrides` of the extension.
+
+  Given the following shared configuration `biome.shared.json`:
+
+  ```json5
+  {
+    "overrides": [
+      {
+        "include": ["**/*.json"],
+        // ...
+      }
+    ]
+  }
+  ```
+
+  and the following configuration:
+
+  ```json5
+  {
+    "extends": ["./biome.shared.json"],
+    "overrides": [
+      {
+        "include": ["**/*.ts"],
+        // ...
+      }
+    ]
+  }
+  ```
+
+  Previously, the `overrides` from `biome.shared.json` was overwritten.
+  It is now merged and results in the following configuration:
+
+  ```json5
+  {
+    "extends": ["./biome.shared.json"],
+    "overrides": [
+      {
+        "include": ["**/*.json"],
+        // ...
+      },
+      {
+        "include": ["**/*.ts"],
+        // ...
+      }
+    ]
+  }
+  ```
+
+  Contributed by @Conaclos
+
 ### Editors
 
 #### Bug fixes

crates/biome_cli/tests/cases/config_extends.rs

@@ -358,3 +358,49 @@ fn allows_reverting_fields_in_extended_config_to_default() {
         result,
     ));
 }
+
+#[test]
+fn extends_config_merge_overrides() {
+    let mut fs = MemoryFileSystem::default();
+    let mut console = BufferConsole::default();
+
+    let shared = Path::new("shared.json");
+    fs.insert(
+        shared.into(),
+        r#"{
+            "overrides": [{
+                "include": ["**/*.js"],
+                "linter": { "rules": { "suspicious": { "noDebugger": "off" } } }
+            }]
+        }"#,
+    );
+
+    let biome_json = Path::new("biome.json");
+    fs.insert(
+        biome_json.into(),
+        r#"{
+            "extends": ["shared.json"],
+            "overrides": [{
+                "include": ["**/*.js"],
+                "linter": { "rules": { "correctness": { "noUnusedVariables": "error" } } }
+            }]
+        }"#,
+    );
+
+    let test_file = Path::new("test.js");
+    fs.insert(test_file.into(), "debugger; const a = 0;");
+
+    let result = run_cli(
+        DynRef::Borrowed(&mut fs),
+        &mut console,
+        Args::from(["lint", test_file.as_os_str().to_str().unwrap()].as_slice()),
+    );
+
+    assert_cli_snapshot(SnapshotPayload::new(
+        module_path!(),
+        "extends_config_merge_overrides",
+        fs,
+        console,
+        result,
+    ));
+}

crates/biome_cli/tests/commands/migrate_eslint.rs

@@ -665,3 +665,41 @@ fn migrate_eslintrcjson_extended_rules() {
         result,
     ));
 }
+
+#[test]
+fn migrate_merge_with_overrides() {
+    let biomejson = r#"{
+        "overrides": [{
+            "include": ["*.js"],
+            "linter": { "enabled": false }
+        }]
+    }"#;
+    let eslintrc = r#"{
+        "overrides": [{
+            "files": ["bin/*.js", "lib/*.js"],
+            "excludedFiles": "*.test.js",
+            "rules": {
+                "eqeqeq": ["off"]
+            }
+        }]
+    }"#;
+
+    let mut fs = MemoryFileSystem::default();
+    fs.insert(Path::new("biome.json").into(), biomejson.as_bytes());
+    fs.insert(Path::new(".eslintrc.json").into(), eslintrc.as_bytes());
+
+    let mut console = BufferConsole::default();
+    let result = run_cli(
+        DynRef::Borrowed(&mut fs),
+        &mut console,
+        Args::from(["migrate", "eslint"].as_slice()),
+    );
+
+    assert_cli_snapshot(SnapshotPayload::new(
+        module_path!(),
+        "migrate_merge_with_overrides",
+        fs,
+        console,
+        result,
+    ));
+}

crates/biome_cli/tests/snapshots/main_cases_config_extends/extends_config_merge_overrides.snap

@@ -0,0 +1,70 @@
+---
+source: crates/biome_cli/tests/snap_test.rs
+expression: content
+---
+## `biome.json`
+
+```json
+{
+  "extends": ["shared.json"],
+  "overrides": [
+    {
+      "include": ["**/*.js"],
+      "linter": { "rules": { "correctness": { "noUnusedVariables": "error" } } }
+    }
+  ]
+}
+```
+
+## `shared.json`
+
+```json
+{
+            "overrides": [{
+                "include": ["**/*.js"],
+                "linter": { "rules": { "suspicious": { "noDebugger": "off" } } }
+            }]
+        }
+```
+
+## `test.js`
+
+```js
+debugger; const a = 0;
+```
+
+# Termination Message
+
+```block
+lint ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  × Some errors were emitted while running checks.
+
+
+
+```
+
+# Emitted Messages
+
+```block
+test.js:1:17 lint/correctness/noUnusedVariables  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  × This variable is unused.
+
+  > 1 │ debugger; const a = 0;
+      │                 ^
+
+  i Unused variables usually are result of incomplete refactoring, typos and other source of bugs.
+
+  i Unsafe fix: If this is intentional, prepend a with an underscore.
+
+  - debugger;·const·a·=·0;
+  + debugger;·const·_a·=·0;
+
+
+```
+
+```block
+Checked 1 file in <TIME>. No fixes applied.
+Found 1 error.
+```

crates/biome_cli/tests/snapshots/main_commands_migrate_eslint/migrate_merge_with_overrides.snap

@@ -0,0 +1,62 @@
+---
+source: crates/biome_cli/tests/snap_test.rs
+expression: content
+---
+## `biome.json`
+
+```json
+{
+  "overrides": [
+    {
+      "include": ["*.js"],
+      "linter": { "enabled": false }
+    }
+  ]
+}
+```
+
+## `.eslintrc.json`
+
+```json
+{
+        "overrides": [{
+            "files": ["bin/*.js", "lib/*.js"],
+            "excludedFiles": "*.test.js",
+            "rules": {
+                "eqeqeq": ["off"]
+            }
+        }]
+    }
+```
+
+# Emitted Messages
+
+```block
+biome.json migrate ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  i Configuration file can be updated.
+
+    1  1 │   {
+    2    │ - ········"overrides":·[{
+    3    │ - ············"include":·["*.js"],
+    4    │ - ············"linter":·{·"enabled":·false·}
+    5    │ - ········}]
+    6    │ - ····}
+       2 │ + → "linter":·{·"rules":·{·"recommended":·false·}·},
+       3 │ + → "overrides":·[
+       4 │ + → → {·"include":·["*.js"],·"linter":·{·"enabled":·false·}·},
+       5 │ + → → {
+       6 │ + → → → "ignore":·["*.test.js"],
+       7 │ + → → → "include":·["bin/*.js",·"lib/*.js"],
+       8 │ + → → → "linter":·{·"rules":·{·"suspicious":·{·"noDoubleEquals":·"off"·}·}·}
+       9 │ + → → }
+      10 │ + → ]
+      11 │ + }
+      12 │ + 
+
+
+```
+
+```block
+Run the command with the option --write to apply the changes.
+```