Improve prpack CLI import safety

src/cli.ts

@@ -1,4 +1,5 @@
 #!/usr/bin/env node
+import { pathToFileURL } from "node:url";
 import { generatePrPack } from "./generate.js";
 
 interface CliOptions {
@@ -103,7 +104,9 @@ export async function run(argv = process.argv.slice(2)): Promise<void> {
   }
 }
 
-run().catch((error: unknown) => {
-  console.error(error instanceof Error ? error.message : String(error));
-  process.exitCode = 1;
-});
+if (process.argv[1] && import.meta.url === pathToFileURL(process.argv[1]).href) {
+  run().catch((error: unknown) => {
+    console.error(error instanceof Error ? error.message : String(error));
+    process.exitCode = 1;
+  });
+}

test/cli.test.ts

@@ -1,5 +1,6 @@
 import assert from "node:assert/strict";
 import { execFile } from "node:child_process";
+import { access, rm } from "node:fs/promises";
 import { promisify } from "node:util";
 import { describe, it } from "node:test";
 
@@ -17,4 +18,12 @@ void describe("cli", () => {
     assert.equal(parsed.pack.title, "Add deterministic PR pack generation");
     assert.match(parsed.pack.prBody, /Reviewer Checklist/);
   });
+
+  void it("can be imported without running the CLI", async () => {
+    await rm("PR_PACK.md", { force: true });
+    const { stdout } = await execFileAsync(process.execPath, ["--input-type=module", "--eval", "import('./dist/src/cli.js').then((mod) => console.log(typeof mod.run))"]);
+
+    assert.equal(stdout.trim(), "function");
+    await assert.rejects(() => access("PR_PACK.md"));
+  });
 });