.

node_modules/jest-config/build/getMaxWorkers.js

@@ -0,0 +1,54 @@
+'use strict';
+
+Object.defineProperty(exports, '__esModule', {
+  value: true
+});
+exports.default = getMaxWorkers;
+
+function _os() {
+  const data = _interopRequireDefault(require('os'));
+
+  _os = function _os() {
+    return data;
+  };
+
+  return data;
+}
+
+function _interopRequireDefault(obj) {
+  return obj && obj.__esModule ? obj : {default: obj};
+}
+
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+function getMaxWorkers(argv) {
+  if (argv.runInBand) {
+    return 1;
+  } else if (argv.maxWorkers) {
+    // TODO: How to type this properly? Should probably use `coerce` from `yargs`
+    const maxWorkers = argv.maxWorkers;
+    const parsed = parseInt(maxWorkers, 10);
+
+    if (
+      typeof maxWorkers === 'string' &&
+      maxWorkers.trim().endsWith('%') &&
+      parsed > 0 &&
+      parsed <= 100
+    ) {
+      const cpus = _os().default.cpus().length;
+
+      const workers = Math.floor((parsed / 100) * cpus);
+      return workers >= 1 ? workers : 1;
+    }
+
+    return parsed > 0 ? parsed : 1;
+  } else {
+    // In watch mode, Jest should be unobtrusive and not use all available CPUs.
+    const cpus = _os().default.cpus() ? _os().default.cpus().length : 1;
+    return Math.max(argv.watch ? Math.floor(cpus / 2) : cpus - 1, 1);
+  }
+}