feat(linter/plugins): support placeholders in messageIds

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

@@ -28,6 +28,7 @@ export interface DiagnosticWithLoc extends DiagnosticBase {
 
 export interface DiagnosticWithMessageId extends DiagnosticBase {
   messageId: string;
+  data?: Record<string, string | number>;
   node?: Ranged;
   loc?: Location;
 }
@@ -161,7 +162,7 @@ export class Context {
     let message: string;
     if (hasOwn(diagnostic, 'messageId')) {
       const diagWithMessageId = diagnostic as DiagnosticWithMessageId;
-      message = this.#resolveMessage(diagWithMessageId.messageId, internal);
+      message = this.#resolveMessage(diagWithMessageId.messageId, diagWithMessageId.data, internal);
     } else {
       message = diagnostic.message;
       if (typeof message !== 'string') {
@@ -212,14 +213,16 @@ export class Context {
   }
 
   /**
-   * Resolve a messageId to its message string.
+   * Resolve a messageId to its message string, with optional data interpolation.
    * @param messageId - The message ID to resolve
+   * @param data - Optional data for placeholder interpolation
    * @param internal - Internal context containing messages
    * @returns Resolved message string
    * @throws {Error} If messageId is not found in messages
    */
   #resolveMessage(
     messageId: string,
+    data: Record<string, string | number> | undefined,
     internal: InternalContext,
   ): string {
     const { messages } = internal;
@@ -236,7 +239,18 @@ export class Context {
       );
     }
 
-    return messages[messageId];
+    let message = messages[messageId];
+
+    // Interpolate placeholders {{key}} with data values
+    if (data) {
+      message = message.replace(/\{\{([^}]+)\}\}/g, (match, key) => {
+        key = key.trim();
+        const value = data[key];
+        return value !== undefined ? String(value) : match;
+      });
+    }
+
+    return message;
   }
 
   static {

apps/oxlint/test/e2e.test.ts

@@ -53,6 +53,10 @@ describe('oxlint CLI', () => {
     await testFixture('message_id_plugin');
   });
 
+  it('should support messageId placeholder interpolation', async () => {
+    await testFixture('message_id_interpolation');
+  });
+
   it('should report an error for unknown messageId', async () => {
     await testFixture('message_id_error');
   });

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

@@ -0,0 +1,9 @@
+{
+  "jsPlugins": ["./plugin.ts"],
+  "categories": {
+    "correctness": "off"
+  },
+  "rules": {
+    "interpolation-test/no-var": "error"
+  }
+}

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

@@ -0,0 +1,5 @@
+var testWithNoData = {};
+var testWithName = {};
+var testWithMultiple = {};
+var testWithMissingData = {};
+var testWithSpaces = {};

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

@@ -0,0 +1,52 @@
+# Exit code
+1
+
+# stdout
+```
+  x interpolation-test(no-var): Variable {{name}} should not use var
+   ,-[files/index.js:1:1]
+ 1 | var testWithNoData = {};
+   : ^^^^^^^^^^^^^^^^^^^^^^^^
+ 2 | var testWithName = {};
+   `----
+
+  x interpolation-test(no-var): Variable testWithName of type string should not use var
+   ,-[files/index.js:2:1]
+ 1 | var testWithNoData = {};
+ 2 | var testWithName = {};
+   : ^^^^^^^^^^^^^^^^^^^^^^
+ 3 | var testWithMultiple = {};
+   `----
+
+  x interpolation-test(no-var): Variable testWithMultiple of type number should not use var
+   ,-[files/index.js:3:1]
+ 2 | var testWithName = {};
+ 3 | var testWithMultiple = {};
+   : ^^^^^^^^^^^^^^^^^^^^^^^^^^
+ 4 | var testWithMissingData = {};
+   `----
+
+  x interpolation-test(no-var): Value is example and name is {{name}}
+   ,-[files/index.js:4:1]
+ 3 | var testWithMultiple = {};
+ 4 | var testWithMissingData = {};
+   : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ 5 | var testWithSpaces = {};
+   `----
+
+  x interpolation-test(no-var): Value with spaces: hello and name: world
+   ,-[files/index.js:5:1]
+ 4 | var testWithMissingData = {};
+ 5 | var testWithSpaces = {};
+   : ^^^^^^^^^^^^^^^^^^^^^^^^
+   `----
+
+Found 0 warnings and 5 errors.
+Finished in Xms on 1 file 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/message_id_interpolation/plugin.ts

@@ -0,0 +1,86 @@
+import type { Plugin } from '../../../dist/index.js';
+
+const plugin: Plugin = {
+  meta: {
+    name: 'interpolation-test',
+  },
+  rules: {
+    'no-var': {
+      meta: {
+        messages: {
+          noData: 'Variables should not use var',
+          withName: 'Variable {{name}} should not use var',
+          withMultiple: 'Variable {{name}} of type {{type}} should not use var',
+          // edge cases
+          missingData: 'Value is {{value}} and name is {{name}}',
+          withSpaces: 'Value with spaces: {{ value }} and name: {{  name  }}',
+        },
+      },
+      create(context) {
+        return {
+          VariableDeclaration(node) {
+            if (node.kind === 'var') {
+              const declarations = node.declarations;
+              if (declarations.length > 0) {
+                const firstDeclaration = declarations[0];
+                if (firstDeclaration.id.type === 'Identifier') {
+                  const name = firstDeclaration.id.name;
+
+                  // Test with single placeholder
+                  if (name === 'testWithNoData') {
+                    context.report({
+                      messageId: 'withName',
+                      node,
+                    });
+                  } // Test with multiple placeholders
+                  else if (name === 'testWithName') {
+                    context.report({
+                      messageId: 'withMultiple',
+                      node,
+                      data: {
+                        name,
+                        type: 'string',
+                      },
+                    });
+                  } // Test without data
+                  else if (name === 'testWithMultiple') {
+                    context.report({
+                      messageId: 'withMultiple',
+                      node,
+                      data: {
+                        name,
+                        type: 'number',
+                      },
+                    });
+                  } else if (name === 'testWithMissingData') {
+                    // Test missing data - placeholder should remain
+                    context.report({
+                      messageId: 'missingData',
+                      node,
+                      data: {
+                        value: 'example',
+                        // name is missing
+                      },
+                    });
+                  } else if (name === 'testWithSpaces') {
+                    // Test whitespace in placeholders
+                    context.report({
+                      messageId: 'withSpaces',
+                      node,
+                      data: {
+                        value: 'hello',
+                        name: 'world',
+                      },
+                    });
+                  }
+                }
+              }
+            }
+          },
+        };
+      },
+    },
+  },
+};
+
+export default plugin;