我的任务是更改背景代码或现有 Mocha 测试以与 Puppeteer 一起运行。这是测试,不应更改:
return assertOnLeft(function (asserter) {
asserter(window.location.href.indexOf("http://XXXX:3000/regression_test_pages/links_page1.html") == 0,
"Address should be links_page.html");
});
我尝试实现 assertOnLeft 函数:
const assertOnLeft = async (predicate) => {
const assert = require("assert");
const asserterOk = assert.ok;
await page.evaluate((asserterOk, predicate) => {
return predicate(asserterOk)
}, asserterOk, predicate)
.catch((e) => console.log("error", e));
}
但我收到一个错误:
error Error: Evaluation failed: TypeError: predicate is not a function
at __puppeteer_evaluation_script__:2:16
at ExecutionContext._evaluateInternal (/node_modules/puppeteer/lib/cjs/puppeteer/common/ExecutionContext.js:218:19)
at processTicksAndRejections (internal/process/task_queues.js:97:5)
at async ExecutionContext.evaluate (/node_modules/puppeteer/lib/cjs/puppeteer/common/ExecutionContext.js:107:16)
at async assertOnLeft (/var/tmp/regression_tests/puppeteer/testWrapper.js:143:5)
答案 0 :(得分:2)
page.evaluate 序列化一个函数并将其发送到 puppeeter 浏览器。 page.evaluate 中的代码不是您代码的一部分,您不能从中调用代码的函数。
如果您想要一个“棘手”的解决方案,您不能尝试 exposeFunction...但通常不是一个好方法。如果您发布预测的代码,我可以为您提供更好的方法
试试这个:
const assert = require("assert");
const asserterOk = assert.ok;
await page.exposeFunction("predicted", predicted);
await page.evaluate((asserterOk, predicate) => {
return predicted(asserterOk, predicate)
}, asserterOk, predicate)
.catch((e) => console.log("error", e));