clean up version lookup code (#804)

packages/cli/src/utils/version.ts

@@ -0,0 +1,34 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { readPackageUp } from 'read-package-up';
+import { fileURLToPath } from 'node:url';
+import { dirname } from 'node:path';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+
+let cliVersion: string | undefined;
+
+export async function getCliVersion(): Promise<string> {
+  if (cliVersion) {
+    return cliVersion;
+  }
+
+  if (process.env.CLI_VERSION) {
+    cliVersion = process.env.CLI_VERSION;
+    return cliVersion;
+  }
+
+  try {
+    const readUpResult = await readPackageUp({ cwd: __dirname });
+    cliVersion = readUpResult?.packageJson.version || 'unknown';
+  } catch (_e) {
+    cliVersion = 'unknown';
+  }
+
+  return cliVersion;
+}