feat(config): make opptions optional for rule with a fix

.changeset/modern-frogs-roll.md

@@ -0,0 +1,24 @@
+---
+"@biomejs/biome": minor
+---
+
+Rule's `options` is now optional in the Biome configuration files for rules with a `fix` kind.
+
+Previously, configuring a rule's `fix` required `options` to be set.
+Now, `options` is optional.
+The following configuration is now valid:
+
+```json
+{
+  "linter": {
+    "rules": {
+      "correctness": {
+        "noUnusedImports": {
+          "level": "on",
+          "fix": "safe"
+        }
+      }
+    }
+  }
+}
+```

crates/biome_cli/src/execute/migrate/eslint_to_biome.rs

@@ -487,7 +487,7 @@ fn migrate_eslint_rule(
                         biome_config::RuleWithFixOptions {
                             level: severity.into(),
                             fix: None,
-                            options: *Box::new((*rule_options).into()),
+                            options: Some(*Box::new((*rule_options).into())),
                         },
                     ));
                 }
@@ -534,7 +534,7 @@ fn migrate_eslint_rule(
                             biome_config::RuleWithFixOptions {
                                 level: severity.into(),
                                 fix: None,
-                                options: *Box::new((*rule_options).into()),
+                                options: Some(*Box::new((*rule_options).into())),
                             },
                         ));
                 }
@@ -551,7 +551,7 @@ fn migrate_eslint_rule(
                             biome_config::RuleWithFixOptions {
                                 level: severity.into(),
                                 fix: None,
-                                options: rule_options.into(),
+                                options: Some(rule_options.into()),
                             },
                         ));
                 }
@@ -567,7 +567,7 @@ fn migrate_eslint_rule(
                         biome_config::RuleWithFixOptions {
                             level: severity.into(),
                             fix: None,
-                            options: rule_options.into(),
+                            options: Some(rule_options.into()),
                         },
                     ));
                 }
@@ -602,7 +602,7 @@ fn migrate_eslint_rule(
                             biome_config::RuleWithFixOptions {
                                 level: severity.into(),
                                 fix: None,
-                                options: options.into(),
+                                options: Some(options.into()),
                             },
                         ));
                 }

crates/biome_cli/tests/cases/config_extends.rs

@@ -550,3 +550,68 @@ fn extends_config_merge_overrides() {
         result,
     ));
 }
+
+#[test]
+fn extends_config_rule_options_merge() {
+    let fs = MemoryFileSystem::default();
+    let mut console = BufferConsole::default();
+
+    let shared = Utf8Path::new("shared.json");
+    fs.insert(
+        shared.into(),
+        r#"{
+            "linter": {
+                "enabled": true,
+                "rules": {
+                    "correctness": {
+                        "noUnusedVariables": {
+                            "level": "on",
+                            "options": {
+                                "ignoreRestSiblings": false
+                            }
+                        }
+                    }
+                }
+            }
+        }"#,
+    );
+
+    let biome_json = Utf8Path::new("biome.json");
+    fs.insert(
+        biome_json.into(),
+        r#"{
+            "extends": ["shared.json"],
+            "linter": {
+                "enabled": true,
+                "rules": {
+                    "correctness": {
+                        "noUnusedVariables": {
+                            "level": "on",
+                            "fix": "safe"
+                        }
+                    }
+                }
+            }
+        }"#,
+    );
+
+    let test_file = Utf8Path::new("test.js");
+    fs.insert(
+        test_file.into(),
+        "const { a, ...rest } = { a: 1, b: 2}; export { rest }",
+    );
+
+    let (fs, result) = run_cli(
+        fs,
+        &mut console,
+        Args::from(["lint", test_file.as_str()].as_slice()),
+    );
+
+    assert_cli_snapshot(SnapshotPayload::new(
+        module_path!(),
+        "extends_config_rule_options_merge",
+        fs,
+        console,
+        result,
+    ));
+}

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

@@ -0,0 +1,70 @@
+---
+source: crates/biome_cli/tests/snap_test.rs
+expression: redactor(content)
+---
+## `biome.json`
+
+```json
+{
+  "extends": ["shared.json"],
+  "linter": {
+    "enabled": true,
+    "rules": {
+      "correctness": {
+        "noUnusedVariables": {
+          "level": "on",
+          "fix": "safe"
+        }
+      }
+    }
+  }
+}
+```
+
+## `shared.json`
+
+```json
+{
+            "linter": {
+                "enabled": true,
+                "rules": {
+                    "correctness": {
+                        "noUnusedVariables": {
+                            "level": "on",
+                            "options": {
+                                "ignoreRestSiblings": false
+                            }
+                        }
+                    }
+                }
+            }
+        }
+```
+
+## `test.js`
+
+```js
+const { a, ...rest } = { a: 1, b: 2}; export { rest }
+```
+
+# Emitted Messages
+
+```block
+test.js:1:9 lint/correctness/noUnusedVariables ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! This variable a is unused.
+  
+  > 1 │ const { a, ...rest } = { a: 1, b: 2}; export { rest }
+      │         ^
+  
+  i Unused variables are often the result of an incomplete refactoring, typos, or other sources of bugs.
+  
+  i You can use the ignoreRestSiblings option to ignore unused variables in an object destructuring with a spread.
+  
+
+```
+
+```block
+Checked 1 file in <TIME>. No fixes applied.
+Found 1 warning.
+```

crates/biome_configuration/src/analyzer/mod.rs

@@ -165,9 +165,10 @@ impl<T: Clone + Default + 'static> RuleFixConfiguration<T> {
     pub fn get_options(&self) -> Option<RuleOptions> {
         match self {
             Self::Plain(_) => None,
-            Self::WithOptions(options) => {
-                Some(RuleOptions::new(options.options.clone(), options.fix))
-            }
+            Self::WithOptions(options) => Some(RuleOptions::new(
+                options.options.clone().unwrap_or_default(),
+                options.fix,
+            )),
         }
     }
 }
@@ -403,14 +404,16 @@ pub struct RuleWithFixOptions<T: Default> {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub fix: Option<FixKind>,
     /// Rule's options
-    pub options: T,
+    pub options: Option<T>,
 }
 
 impl<T: Default> Merge for RuleWithFixOptions<T> {
     fn merge_with(&mut self, other: Self) {
         self.level = other.level;
         self.fix = other.fix.or(self.fix);
-        self.options = other.options;
+        if other.options.is_some() {
+            self.options = other.options;
+        }
     }
 }
 

crates/biome_configuration/tests/valid/optional_options.json

@@ -0,0 +1,12 @@
+{
+  "linter": {
+    "rules": {
+      "correctness": {
+        "noUnusedImports": {
+          "level": "on",
+          "fix": "safe"
+        }
+      }
+    }
+  }
+}