diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..fb9cdeb
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,39 @@
+name: Test
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+    paths:
+      - '**/*.[tj]s'
+      - '**/*.?[tj]s'
+      - 'tsconfig.json'
+      - 'package.json'
+      - 'package-lock.json'
+      - '.nvmrc'
+      - '.github/workflows/test.yml'
+
+jobs:
+  test:
+    runs-on: blacksmith-2vcpu-ubuntu-2404
+    steps:
+      - name: Checkout
+        # 6.0.3
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10
+
+      # v6.1.0
+      - name: Setup Node
+        uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f
+        with:
+          node-version-file: .nvmrc
+          cache: npm
+          cache-dependency-path: package-lock.json
+
+      - name: Install npm packages
+        run: npm ci
+
+      - name: Run unit tests
+        run: npm test
+
+      - name: Tell people how to run the failing check
+        if: failure()
+        run: echo "::error::The test check failed! To run it locally, run \`npm ci && npm test\` from the GitHub-Actions repo root."
diff --git a/package.json b/package.json
index 557feb7..5220491 100644
--- a/package.json
+++ b/package.json
@@ -5,7 +5,8 @@
   "scripts": {
     "fmt": "oxfmt --write .",
     "typecheck": "tsgo --noEmit -p tsconfig.json",
-    "verify-peer-review": "tsx scripts/verifyPeerReview.ts"
+    "verify-peer-review": "tsx scripts/verifyPeerReview.ts",
+    "test": "tsx --test tests/*.test.ts"
   },
   "dependencies": {
     "expensify-common": "2.0.189"
diff --git a/tests/verifyPeerReviewCli.test.ts b/tests/verifyPeerReviewCli.test.ts
new file mode 100644
index 0000000..b906c13
--- /dev/null
+++ b/tests/verifyPeerReviewCli.test.ts
@@ -0,0 +1,33 @@
+import assert from 'node:assert/strict';
+import {afterEach, beforeEach, describe, it} from 'node:test';
+
+import VerifyPeerReview from '../scripts/verifyPeerReview';
+
+const ORIGINAL_ARGV = process.argv;
+
+describe('main CLI parsing', () => {
+    let originalExit: typeof process.exit;
+
+    beforeEach(() => {
+        process.argv = ['tsx', 'scripts/verifyPeerReview.ts'];
+        originalExit = process.exit.bind(process);
+        process.exit = (code?: string | number | null) => {
+            throw new Error(`exit ${code ?? 0}`);
+        };
+    });
+
+    afterEach(() => {
+        process.argv = ORIGINAL_ARGV;
+        process.exit = originalExit;
+    });
+
+    it('parses required pull request CLI arguments', async () => {
+        process.argv.push('--owner', 'Expensify', '--repo', 'Auth', '--pull-request-number', '21136', '--base-ref', 'main');
+
+        await assert.doesNotReject(() => VerifyPeerReview.main());
+    });
+
+    it('fails when required arguments are missing', async () => {
+        await assert.rejects(() => VerifyPeerReview.main(), /exit 1/);
+    });
+});