Add license-comments eslint rule

.eslint/rules/license-comments.js

@@ -0,0 +1,73 @@
+// Copyright 2025 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+const COMMENT_LINE_1_EXACT = /^ Copyright \d{4} Signal Messenger, LLC$/;
+const COMMENT_LINE_2_EXACT = /^ SPDX-License-Identifier: AGPL-3.0-only$/;
+
+const COMMENT_LINE_1_LOOSE = /Copyright (\d{4}) Signal Messenger, LLC/;
+const COMMENT_LINE_2_LOOSE = /SPDX-License-Identifier: AGPL-3.0-only/;
+
+/** @type {import("eslint").Rule.RuleModule} */
+module.exports = {
+  meta: {
+    type: 'problem',
+    hasSuggestions: false,
+    fixable: true,
+    schema: [],
+  },
+  create(context) {
+    return {
+      Program(node) {
+        let comment1 = node.comments.at(0);
+        let comment2 = node.comments.at(1);
+
+        if (
+          comment1?.type === 'Line' &&
+          comment2?.type === 'Line' &&
+          COMMENT_LINE_1_EXACT.test(comment1.value) &&
+          COMMENT_LINE_2_EXACT.test(comment2.value)
+        ) {
+          return;
+        }
+
+        context.report({
+          node,
+          message: 'Missing license comment',
+
+          fix(fixer) {
+            let year = null;
+            let remove = [];
+
+            for (let comment of node.comments) {
+              let match1 = comment.value.match(COMMENT_LINE_1_LOOSE);
+              let match2 = comment.value.match(COMMENT_LINE_2_LOOSE);
+
+              if (match1 != null) {
+                year = match1[1];
+              }
+
+              if (match1 != null || match2 != null) {
+                remove.push(comment);
+              }
+            }
+
+            year ??= new Date().getFullYear().toString();
+
+            let insert =
+              `// Copyright ${year} Signal Messenger, LLC\n` +
+              '// SPDX-License-Identifier: AGPL-3.0-only\n';
+
+            return [
+              fixer.replaceTextRange([0, 0], insert),
+              ...remove.map(comment => {
+                return fixer.replaceTextRange(
+                  [comment.range[0], comment.range[1]],
+                  ''
+                );
+              }),
+            ];
+          },
+        });
+      },
+    };
+  },
+};

.eslintrc.js

@@ -179,6 +179,7 @@ const rules = {
       additionalHooks: '^(useSpring|useSprings)$',
     },
   ],
+  'local-rules/license-comments': 'error',
 };
 
 const typescriptRules = {

eslint-local-rules.js

@@ -3,5 +3,6 @@
 /* eslint-disable global-require */
 
 module.exports = {
+  'license-comments': require('./.eslint/rules/license-comments'),
   'type-alias-readonlydeep': require('./.eslint/rules/type-alias-readonlydeep'),
 };

ts/state/smart/MessageSearchResult.tsx

@@ -1,5 +1,5 @@
 // Copyright 2019 Signal Messenger, LLC
-// SPDX-License-Identifier: AGPL-3.0-onlyå
+// SPDX-License-Identifier: AGPL-3.0-only
 import React, { memo } from 'react';
 import { useSelector } from 'react-redux';
 import { MessageSearchResult } from '../../components/conversationList/MessageSearchResult';