test: wrap countdown callback in common.mustCall

This adds a implicit common.mustCall to the callback provided to
the countdown.

PR-URL: https://github.com/nodejs/node/pull/18506
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 20 insertions, 2 deletions

diff --git a/test/parallel/test-common-countdown.js b/test/parallel/test-common-countdown.js
index ec0543f36f..6a1a2f1bbc 100644
--- a/test/parallel/test-common-countdown.js
+++ b/test/parallel/test-common-countdown.js
@@ -3,13 +3,31 @@
 const common = require('../common');
 const assert = require('assert');
 const Countdown = require('../common/countdown');
+const fixtures = require('../common/fixtures');
+const { execFile } = require('child_process');
 
 let done = '';
-
-const countdown = new Countdown(2, common.mustCall(() => done = true));
+const countdown = new Countdown(2, () => done = true);
 assert.strictEqual(countdown.remaining, 2);
 countdown.dec();
 assert.strictEqual(countdown.remaining, 1);
 countdown.dec();
 assert.strictEqual(countdown.remaining, 0);
 assert.strictEqual(done, true);
+
+const failFixtures = [
+  [
+    fixtures.path('failcounter.js'),
+    'Mismatched <anonymous> function calls. Expected exactly 1, actual 0.',
+  ]
+];
+
+for (const p of failFixtures) {
+  const [file, expected] = p;
+  execFile(process.argv[0], [file], common.mustCall((ex, stdout, stderr) => {
+    assert.ok(ex);
+    assert.strictEqual(stderr, '');
+    const firstLine = stdout.split('\n').shift();
+    assert.strictEqual(firstLine, expected);
+  }));
+}