1 files changed, 41 insertions, 0 deletions
diff --git a/test/parallel/test-worker-memory.js b/test/parallel/test-worker-memory.js
new file mode 100644
index 0000000000..34b1e0acaf
--- /dev/null
+++ b/test/parallel/test-worker-memory.js
@@ -0,0 +1,41 @@
+// Flags: --experimental-worker
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const util = require('util');
+const { Worker } = require('worker');
+
+const numWorkers = +process.env.JOBS || require('os').cpus().length;
+
+// Verify that a Worker's memory isn't kept in memory after the thread finishes.
+
+function run(n, done) {
+  if (n <= 0)
+    return done();
+  const worker = new Worker(
+    'require(\'worker\').parentPort.postMessage(2 + 2)',
+    { eval: true });
+  worker.on('message', common.mustCall((value) => {
+    assert.strictEqual(value, 4);
+  }));
+  worker.on('exit', common.mustCall(() => {
+    run(n - 1, done);
+  }));
+}
+
+const startStats = process.memoryUsage();
+let finished = 0;
+for (let i = 0; i < numWorkers; ++i) {
+  run(60 / numWorkers, () => {
+    if (++finished === numWorkers) {
+      const finishStats = process.memoryUsage();
+      // A typical value for this ratio would be ~1.15.
+      // 5 as a upper limit is generous, but the main point is that we
+      // don't have the memory of 50 Isolates/Node.js environments just lying
+      // around somewhere.
+      assert.ok(finishStats.rss / startStats.rss < 5,
+                'Unexpected memory overhead: ' +
+                util.inspect([startStats, finishStats]));
+    }
+  });
+}