참고소스 수정본

참고/playwright-main/packages/utils/task.ts

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+/**
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// See https://joel.tools/microtasks/
+export function makeWaitForNextTask() {
+  // As of Mar 2021, Electron v12 doesn't create new task with `setImmediate` despite
+  // using Node 14 internally, so we fallback to `setTimeout(0)` instead.
+  // @see https://github.com/electron/electron/issues/28261
+  if ((process.versions as any).electron)
+    return (callback: () => void) => setTimeout(callback, 0);
+  if (parseInt(process.versions.node, 10) >= 11)
+    return setImmediate;
+
+  // Unlike Node 11, Node 10 and less have a bug with Task and MicroTask execution order:
+  // - https://github.com/nodejs/node/issues/22257
+  //
+  // So we can't simply run setImmediate to dispatch code in a following task.
+  // However, we can run setImmediate from-inside setImmediate to make sure we're getting
+  // in the following task.
+
+  let spinning = false;
+  const callbacks: (() => void)[] = [];
+  const loop = () => {
+    const callback = callbacks.shift();
+    if (!callback) {
+      spinning = false;
+      return;
+    }
+    setImmediate(loop);
+    // Make sure to call callback() as the last thing since it's
+    // untrusted code that might throw.
+    callback();
+  };
+
+  return (callback: () => void) => {
+    callbacks.push(callback);
+    if (!spinning) {
+      spinning = true;
+      setImmediate(loop);
+    }
+  };
+}