add linter for checking license headers (and eslint --fix target to match, and fix missing license headers while we're here) (#62)

8 files changed, 72 insertions, 0 deletions

diff --git a/eslint.config.js b/eslint.config.js
index ae924cc7..a846d22d 100644
--- a/eslint.config.js
+++ b/eslint.config.js
@@ -12,6 +12,7 @@ import reactHooks from 'eslint-plugin-react-hooks';
 import prettierConfig from 'eslint-config-prettier';
 import importPlugin from 'eslint-plugin-import';
 import globals from 'globals';
+import licenseHeader from 'eslint-plugin-license-header';
 
 export default tseslint.config(
   {
@@ -142,6 +143,24 @@ export default tseslint.config(
       'default-case': 'error',
     },
   },
+  {
+    files: ['./**/*.{tsx,ts,js}'],
+    plugins: {
+      'license-header': licenseHeader,
+    },
+    rules: {
+      'license-header/header': [
+        'error',
+        [
+          '/**',
+          ' * @license',
+          ' * Copyright 2025 Google LLC',
+          ' * SPDX-License-Identifier: Apache-2.0',
+          ' */',
+        ],
+      ],
+    },
+  },
   // Prettier config must be last
   prettierConfig,
 );
diff --git a/package-lock.json b/package-lock.json
index 18c09048..1930a77a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -14,6 +14,7 @@
         "eslint": "^9.24.0",
         "eslint-config-prettier": "^10.1.2",
         "eslint-plugin-import": "^2.31.0",
+        "eslint-plugin-license-header": "^0.8.0",
         "eslint-plugin-react": "^7.37.5",
         "eslint-plugin-react-hooks": "^5.2.0",
         "globals": "^16.0.0",
@@ -2796,6 +2797,16 @@
         "ms": "^2.1.1"
       }
     },
+    "node_modules/eslint-plugin-license-header": {
+      "version": "0.8.0",
+      "resolved": "https://registry.npmjs.org/eslint-plugin-license-header/-/eslint-plugin-license-header-0.8.0.tgz",
+      "integrity": "sha512-khTCz6G3JdoQfwrtY4XKl98KW4PpnWUKuFx8v+twIRhJADEyYglMDC0td8It75C1MZ88gcvMusWuUlJsos7gYg==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "requireindex": "^1.2.0"
+      }
+    },
     "node_modules/eslint-plugin-react": {
       "version": "7.37.5",
       "resolved": "https://registry.npmjs.org/eslint-plugin-react/-/eslint-plugin-react-7.37.5.tgz",
@@ -4968,6 +4979,16 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/requireindex": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/requireindex/-/requireindex-1.2.0.tgz",
+      "integrity": "sha512-L9jEkOi3ASd9PYit2cwRfyppc9NoABujTP8/5gFcbERmo5jUoAKovIC3fsF17pkTnGsrByysqX+Kxd2OTNI1ww==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=0.10.5"
+      }
+    },
     "node_modules/resolve": {
       "version": "1.22.10",
       "resolved": "https://registry.npmjs.org/resolve/-/resolve-1.22.10.tgz",
diff --git a/package.json b/package.json
index 240c7ca3..b0d56370 100644
--- a/package.json
+++ b/package.json
@@ -12,6 +12,7 @@
     "test": "npm run test --workspaces",
     "start": "scripts/start.sh",
     "debug": "scripts/debug.sh",
+    "fix": "eslint . --fix",
     "lint": "eslint . --ext .ts,.tsx",
     "typecheck": "tsc --noEmit --jsx react",
     "format": "prettier --write .",
@@ -22,6 +23,7 @@
     "eslint": "^9.24.0",
     "eslint-config-prettier": "^10.1.2",
     "eslint-plugin-import": "^2.31.0",
+    "eslint-plugin-license-header": "^0.8.0",
     "eslint-plugin-react": "^7.37.5",
     "eslint-plugin-react-hooks": "^5.2.0",
     "globals": "^16.0.0",
diff --git a/packages/cli/src/index.test.ts b/packages/cli/src/index.test.ts
index bbe9fa8b..9d65e38f 100644
--- a/packages/cli/src/index.test.ts
+++ b/packages/cli/src/index.test.ts
@@ -1,3 +1,9 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 import { describe, it, expect } from 'vitest';
 import { toolRegistry } from './tools/tool-registry.js';
 
diff --git a/packages/cli/src/ui/colors.ts b/packages/cli/src/ui/colors.ts
index be8dac19..946be512 100644
--- a/packages/cli/src/ui/colors.ts
+++ b/packages/cli/src/ui/colors.ts
@@ -1,3 +1,9 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 export const Colors = {
   Background: '#1E1E2E',
   Foreground: 'white',
diff --git a/packages/cli/src/ui/hooks/useStdin.ts b/packages/cli/src/ui/hooks/useStdin.ts
index 8c741c9b..e91b90e6 100644
--- a/packages/cli/src/ui/hooks/useStdin.ts
+++ b/packages/cli/src/ui/hooks/useStdin.ts
@@ -1,3 +1,9 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 import { useState, useEffect } from 'react';
 import { useStdin } from 'ink';
 
diff --git a/packages/server/src/core/turn.ts b/packages/server/src/core/turn.ts
index bf5c3e86..3d8c8c76 100644
--- a/packages/server/src/core/turn.ts
+++ b/packages/server/src/core/turn.ts
@@ -1,3 +1,9 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 import {
   Part,
   Chat,
diff --git a/packages/server/src/index.test.ts b/packages/server/src/index.test.ts
index 50c8a54e..154c96a6 100644
--- a/packages/server/src/index.test.ts
+++ b/packages/server/src/index.test.ts
@@ -1,3 +1,9 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 import { describe, it, expect } from 'vitest';
 
 describe('placeholder tests', () => {