From d65f9312ea83a50db0642d476b22fac982a7a870 Mon Sep 17 00:00:00 2001
From: Daniel Imms <2193314+Tyriar@users.noreply.github.com>
Date: Thu, 8 Jan 2026 17:32:15 -0800
Subject: [PATCH 1/2] Add lint-changes npm scripts

---
 bin/lint_changes.js | 49 +++++++++++++++++++++++++++++++++++++++++++++
 package.json        |  2 ++
 2 files changed, 51 insertions(+)
 create mode 100644 bin/lint_changes.js

diff --git a/bin/lint_changes.js b/bin/lint_changes.js
new file mode 100644
index 00000000..a8edb44c
--- /dev/null
+++ b/bin/lint_changes.js
@@ -0,0 +1,49 @@
+/**
+ * Copyright (c) 2026 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+// @ts-check
+
+const { execSync, spawn } = require('child_process');
+const path = require('path');
+
+const extensions = ['.ts', '.mts'];
+const fix = process.argv.includes('--fix');
+
+// Get uncommitted changed files (staged + unstaged)
+function getChangedFiles() {
+  try {
+    const output = execSync('git diff --name-only --diff-filter=ACMR HEAD', {
+      encoding: 'utf-8',
+      cwd: path.join(__dirname, '..')
+    });
+    return output.split('\n').filter(f => f && extensions.some(ext => f.endsWith(ext)));
+  } catch {
+    return [];
+  }
+}
+
+const files = getChangedFiles();
+
+if (files.length === 0) {
+  console.log('No changed TypeScript files to lint.');
+  process.exit(0);
+}
+
+console.log(`Linting ${files.length} changed file(s)...`);
+
+const eslintArgs = ['--max-warnings', '0'];
+if (fix) {
+  eslintArgs.push('--fix');
+}
+eslintArgs.push(...files);
+
+const eslint = process.platform === 'win32' ? 'eslint.cmd' : 'eslint';
+const child = spawn(eslint, eslintArgs, {
+  stdio: 'inherit',
+  cwd: path.join(__dirname, '..'),
+  shell: process.platform === 'win32'
+});
+
+child.on('close', code => process.exit(code ?? 0));
diff --git a/package.json b/package.json
index ecb60ef4..9b54946c 100644
--- a/package.json
+++ b/package.json
@@ -48,6 +48,8 @@
     "test": "npm run test-unit",
     "posttest": "npm run lint",
     "lint": "eslint --max-warnings 0 src/ addons/ demo/",
+    "lint-changes": "node ./bin/lint_changes.js",
+    "lint-changes-fix": "node ./bin/lint_changes.js --fix",
     "lint-fix": "eslint --fix src/ addons/ demo/",
     "lint-api": "eslint --config eslint.config.typings.mjs --max-warnings 0 typings/",
     "test-unit": "node ./bin/test_unit.js",

From d6f6a6af9a7df03c3feaa3ff0e1a97fb9b28ae7c Mon Sep 17 00:00:00 2001
From: Daniel Imms <2193314+Tyriar@users.noreply.github.com>
Date: Thu, 8 Jan 2026 17:32:50 -0800
Subject: [PATCH 2/2] Lint instructions

---
 .github/copilot-instructions.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index 97325cb8..461f8fdb 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -26,6 +26,7 @@ npm run build && npm run esbuild # Build all TypeScript and bundle
 - Integration tests: `npm run test-integration` (Playwright across Chrome/Firefox/WebKit)
 - Integration tests by file: `npm run test-integration -- test/playwright/InputHandler.test.ts`. Never use grep to filter tests, it doesn't work
 - Integration tests by addon: `npm run test-integration --suite=addon-search`. Suites always follow the format `addon-<something>`
+- Lint changes: `npm run lint-changes` to lint only changed files, `npm run lint-changes-fix` to fix them
 
 ## Addon Development Pattern