Add test:worker script that runs the mocha tests inside a worker

package.json

@@ -50,7 +50,8 @@
     "prepublishOnly": "npm ls",
     "install": "node-pre-gyp install --fallback-to-build",
     "pretest": "node test/support/createdb.js",
-    "test": "mocha -R spec --timeout 480000"
+    "test": "mocha -R spec --timeout 480000",
+    "test:worker": "node --experimental-worker scripts/mocha-as-worker.js -R spec --timeout 480000"
   },
   "license": "BSD-3-Clause",
   "keywords": [

scripts/mocha-as-worker.js

+// Run the mocha tests in a worker
+// Not a clean approach, but is sufficient to verify correctness
+const worker_threads = require("worker_threads");
+const path = require("path");
+
+if (worker_threads.isMainThread) {
+	const worker = new worker_threads.Worker(__filename, { workerData: { windowSize: process.stdout.getWindowSize() } });
+	worker.on("error", console.error);
+} else {
+	process.stdout.getWindowSize = () => worker_threads.workerData.windowSize;
+	const mochaPath = path.resolve(require.resolve("mocha"), "../bin/_mocha");
+	require(mochaPath);
+}