调用await browser.close（）时出错：（节点：4960）UnhandledPromiseRejectionWarning：page.goto：导航失败，因为页面已关闭

Question

我的目标：

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在加载第一个页面（一个巨大的 html）时导航到第二个页面。

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当前状态：

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该脚本一直运行到最后，然后await browser.close()崩溃。

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剧本：

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const { chromium } = require(\'playwright\');\n\n(async () => {\n  const browser = await chromium.launch({ headless: false })\n  const page = await browser.newPage()\n\n  await page.setViewportSize({ width: 1200, height: 800 })\n\n  // asynchronous loading\n  page.goto(\'http://localhost:1234/index1.htm\')\n\n  // wait for the button that navigates to another page\n  await page.waitForSelector(\'#button1\');\n  \n  // button exists. Click it to navigate to index2.htm\n  await page.click(\'#button1\')\n  \n  // await the #first_span element exists in index2.htm to do something\n  await page.waitForSelector(\'#first_span\')\n  \n  // doing something\n  console.log(\'First span is visible. Do something.\')\n  \n  // finish the browser (this causes an error)\n  await browser.close()\n})()\n\n

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错误：

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\xce\xbb node nav.js                                                                                                                                                                                                                                 \nFirst span is visible. Do something.                                                                                                                                                                                                          \n(node:6356) UnhandledPromiseRejectionWarning: page.goto: Navigation failed because page was closed!                                                                                                                                           \n=========================== logs ===========================                                                                                                                                                                                  \nnavigating to "http://localhost:1234/index1.htm", waiting until "load"                                                                                                                                                                         \n============================================================                                                                                                                                                                                  \nNote: use DEBUG=pw:api environment variable to capture Playwright logs.                                                                                                                                                                       \nError                                                                                                                                                                                                                                         \n    at Object.captureStackTrace (C:\\repositorios\\playwright\\node_modules\\playwright\\lib\\utils\\stackTrace.js:48:19)                                                                                                                            \n    at Connection.sendMessageToServer (C:\\repositorios\\playwright\\node_modules\\playwright\\lib\\client\\connection.js:69:48)                                                                                                                     \n    at Proxy.<anonymous> (C:\\repositorios\\playwright\\node_modules\\playwright\\lib\\client\\channelOwner.js:64:61)                                                                                                                                \n    at C:\\repositorios\\playwright\\node_modules\\playwright\\lib\\client\\frame.js:102:65                                                                                                                                                          \n    at Frame._wrapApiCall (C:\\repositorios\\playwright\\node_modules\\playwright\\lib\\client\\channelOwner.js:77:34)                                                                                                                               \n    at Frame.goto (C:\\repositorios\\playwright\\node_modules\\playwright\\lib\\client\\frame.js:100:21)                                                                                                                                             \n    at C:\\repositorios\\playwright\\node_modules\\playwright\\lib\\client\\page.js:296:60                                                                                                                                                           \n    at Page._attributeToPage (C:\\repositorios\\playwright\\node_modules\\playwright\\lib\\client\\page.js:231:20)                                                                                                                                   \n    at Page.goto (C:\\repositorios\\playwright\\node_modules\\playwright\\lib\\client\\page.js:296:21)                                                                                                                                               \n    at C:\\repositorios\\playwright\\nav.js:9:8                                                                                                                                                                                                  \n(node:6356) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To termi\nnate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)                                                 \n(node:6356) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.                                   \n

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如何防止这个错误呢？

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谢谢。

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Answer 1

page.goto由于未等待而引发错误：

// asynchronous loading
page.goto('http://localhost:1234/index1.htm')

原因是page.goto返回一个 Promise，但是当它等待load事件解决它时：导航到第二页 ( index2.htm) 的发生早于加载事件发生的时间。所以结果是一个UnhandledPromiseRejectionWarning.
[N]avigating to "http://localhost:1234/index1.htm", waiting until "load"也给出了关于这一点的提示。

通过将其更改为：

// asynchronous loading
await page.goto('http://localhost:1234/index1.htm')

你不会得到错误。

在某些用例中，组合未等待page.goto且page.waitForSelector在 Puppeteer/Playwright 中可能有效，但是当您在 goto 之后立即进行导航时，会导致上述错误。