feat(ui): add i18n linting warning rules (apache#51131)

* feat(ui): add i18n linting warning rules

* fix: check files under src directory

Author: RoyLee1224

airflow-core/src/airflow/ui/eslint.config.js

@@ -21,6 +21,7 @@
  * @import { FlatConfig } from "@typescript-eslint/utils/ts-eslint";
  */
 import { coreRules } from "./rules/core.js";
+import { i18nextRules } from "./rules/i18next.js";
 import { perfectionistRules } from "./rules/perfectionist.js";
 import { prettierRules } from "./rules/prettier.js";
 import { reactRules } from "./rules/react.js";
@@ -44,4 +45,5 @@ export default /** @type {const} @satisfies {ReadonlyArray<FlatConfig.Config>} *
   reactRules,
   stylisticRules,
   unicornRules,
+  i18nextRules,
 ]);

airflow-core/src/airflow/ui/package.json

@@ -75,6 +75,7 @@
     "@vitest/coverage-v8": "^2.1.9",
     "eslint": "^9.25.1",
     "eslint-config-prettier": "^10.1.2",
+    "eslint-plugin-i18next": "^6.1.1",
     "eslint-plugin-jsx-a11y": "^6.10.2",
     "eslint-plugin-perfectionist": "^4.12.3",
     "eslint-plugin-prettier": "^5.2.6",

airflow-core/src/airflow/ui/pnpm-lock.yaml

@@ -0,0 +1,65 @@
+/*!
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/**
+ * @import { FlatConfig } from "@typescript-eslint/utils/ts-eslint";
+ */
+import i18nextPlugin from "eslint-plugin-i18next";
+
+import { WARN } from "./levels.js";
+
+const allExtensions = "*.{j,t}s{x,}";
+
+/**
+ * ESLint rules for i18next to enforce internationalization best practices.
+ * This is a customized configuration.
+ *
+ * @see [eslint-plugin-i18next](https://github.com/edvardchen/eslint-plugin-i18next)
+ */
+export const i18nextRules = /** @type {const} @satisfies {FlatConfig.Config} */ ({
+  files: [
+    // Check files in the ui/src directory
+    `src/**/${allExtensions}`,
+  ],
+  plugins: {
+    i18next: i18nextPlugin,
+  },
+  rules: {
+    /**
+     * Enforce no literal strings in JSX/TSX markup.
+     * This rule helps ensure all user-facing strings are properly internationalized.
+     *
+     * @example
+     * ```typescript
+     * // ❌ Incorrect
+     * <div>Hello, world!</div>
+     *
+     * // ✅ Correct
+     * <div>{translate('greeting')}</div>
+     * ```
+     * @see [i18next/no-literal-string](https://github.com/edvardchen/eslint-plugin-i18next#no-literal-string)
+     */
+    "i18next/no-literal-string": [
+      WARN,
+      {
+        markupOnly: true,
+      },
+    ],
+  },
+});