fix(linter): accept bools as valid values for fixable (#18772)

fixes #17967
fixes #18700
closes #18011

This PR allows boolean values as valid options for meta.fixable. While this technically doesn't align exactly with eslint, it reduces some friction about getting users to migrate from exlint to oxlint, by increasing the number of plugins that are compatible.

Author: camc314

apps/oxlint/src-js/plugins/load.ts

@@ -181,10 +181,17 @@ export function registerPlugin(
 
       const { fixable } = ruleMeta;
       if (fixable != null) {
-        if (fixable !== "code" && fixable !== "whitespace") {
+        // `true` and `false` aren't valid values for `meta.fixable`, but we accept them for
+        // backward compatibility with some ESLint plugins
+        if (
+          fixable !== "code" &&
+          fixable !== "whitespace" &&
+          fixable !== true &&
+          fixable !== false
+        ) {
           throw new TypeError("Invalid `rule.meta.fixable`");
         }
-        isFixable = true;
+        isFixable = (fixable as "code" | "whitespace" | true | false) !== false;
       }
 
       // If `schema` provided, compile schema to validator for applying schema defaults to options

apps/oxlint/test/fixtures/fixable_boolean/.oxlintrc.json

@@ -0,0 +1,10 @@
+{
+  "jsPlugins": ["./plugin.ts"],
+  "categories": {
+    "correctness": "off"
+  },
+  "rules": {
+    "fixable-boolean-plugin/no-debugger-true": "error",
+    "fixable-boolean-plugin/no-console-false": "error"
+  }
+}

apps/oxlint/test/fixtures/fixable_boolean/files/index.js

@@ -0,0 +1,2 @@
+debugger;
+console.log("test");

apps/oxlint/test/fixtures/fixable_boolean/fix.snap.md

@@ -0,0 +1,28 @@
+# Exit code
+1
+
+# stdout
+```
+  x fixable-boolean-plugin(no-console-false): Console with fixable: false
+   ,-[files/index.js:2:1]
+ 1 | debugger;
+ 2 | console.log("test");
+   : ^^^^^^^^^^^^^^^^^^^
+   `----
+
+Found 0 warnings and 1 error.
+Finished in Xms on 1 file with 2 rules using X threads.
+```
+
+# stderr
+```
+WARNING: JS plugins are experimental and not subject to semver.
+Breaking changes are possible while JS plugins support is under development.
+```
+
+# File altered: files/index.js
+```
+
+console.log("test");
+
+```

apps/oxlint/test/fixtures/fixable_boolean/options.json

@@ -0,0 +1,3 @@
+{
+  "fix": true
+}

apps/oxlint/test/fixtures/fixable_boolean/output.snap.md

@@ -0,0 +1,28 @@
+# Exit code
+1
+
+# stdout
+```
+  x fixable-boolean-plugin(no-debugger-true): Debugger with fixable: true
+   ,-[files/index.js:1:1]
+ 1 | debugger;
+   : ^^^^^^^^^
+ 2 | console.log("test");
+   `----
+
+  x fixable-boolean-plugin(no-console-false): Console with fixable: false
+   ,-[files/index.js:2:1]
+ 1 | debugger;
+ 2 | console.log("test");
+   : ^^^^^^^^^^^^^^^^^^^
+   `----
+
+Found 0 warnings and 2 errors.
+Finished in Xms on 1 file with 2 rules using X threads.
+```
+
+# stderr
+```
+WARNING: JS plugins are experimental and not subject to semver.
+Breaking changes are possible while JS plugins support is under development.
+```

apps/oxlint/test/fixtures/fixable_boolean/plugin.ts

@@ -0,0 +1,54 @@
+import type { Plugin } from "#oxlint/plugin";
+
+// Test backward compatibility for `meta.fixable: true` and `meta.fixable: false`
+// which some ESLint plugins use instead of "code" or "whitespace"
+const plugin: Plugin = {
+  meta: {
+    name: "fixable-boolean-plugin",
+  },
+  rules: {
+    // Rule with fixable: true (backward compatibility)
+    "no-debugger-true": {
+      meta: {
+        fixable: true as any,
+      },
+      create(context) {
+        return {
+          DebuggerStatement(node) {
+            context.report({
+              message: "Debugger with fixable: true",
+              node,
+              fix(fixer) {
+                return fixer.remove(node);
+              },
+            });
+          },
+        };
+      },
+    },
+    // Rule with fixable: false (backward compatibility)
+    "no-console-false": {
+      meta: {
+        fixable: false as any,
+      },
+      create(context) {
+        return {
+          CallExpression(node) {
+            if (
+              node.callee.type === "MemberExpression" &&
+              node.callee.object.type === "Identifier" &&
+              node.callee.object.name === "console"
+            ) {
+              context.report({
+                message: "Console with fixable: false",
+                node,
+              });
+            }
+          },
+        };
+      },
+    },
+  },
+};
+
+export default plugin;