Added an utility that validates GitHub token.

src/check-token.ts

@@ -0,0 +1,29 @@
+import { parseArgs } from 'util';
+import { fetchLatestRelease } from './core/downloader';
+
+async function run() {
+  const { positionals } = parseArgs({
+    allowPositionals: true
+  });
+
+  const token = positionals[0] || process.env.GITHUB_TOKEN;
+
+  if (!token) {
+    console.error('Error: No GitHub token provided as an argument or found in GITHUB_TOKEN environment variable.');
+    process.exit(1);
+  }
+
+  try {
+    console.log('Verifying GitHub token...');
+    // Attempt to list latest release of actions/checkout as a test
+    await fetchLatestRelease('actions/checkout', token);
+
+    console.log('\x1b[32mSuccess: The provided GitHub token is valid and has sufficient permissions to access public repositories.\x1b[0m');
+  } catch (error: any) {
+    console.error('\x1b[31mError: GitHub token verification failed.\x1b[0m');
+    console.error(`Reason: ${error.message}`);
+    process.exit(1);
+  }
+}
+
+run();