Jest-puppeteer: Failing tests will throw an UnhandledPromiseRejectionWarning but will still pass.

[dptoot]

🐛 Bug Report

Failing tests will throw an UnhandledPromiseRejectionWarning but will still pass.
This has been brought up in another issue as a side effect.
https://github.com/smooth-code/jest-puppeteer/issues/106#issuecomment-426245782

It is possible this is a windows specific bug

 PASS  test/integration/app.test.js (10.084s)
  app
    √ renders the page (8320ms)

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        10.158s, estimated 14s
Ran all test suites.
(node:18816) UnhandledPromiseRejectionWarning: Error: Text not found "Page Renders"
Protocol error (Runtime.callFunctionOn): Target closed.
(node:18816) 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(). (rejection id: 1)
(node:18816) [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.

If I add a timeout after each test of something over the 500ms timeout.

afterEach(async () => {
       await new Promise(resolve => setTimeout(resolve, 550));
});

then it will fail tests

 FAIL  test/integration/app.test.js (10.712s)             
  app                                                     
    × renders the page (8946ms)                           

  ● app › renders the page                                

    TimeoutError: Text found "Page Renders"               

      waiting for function failed: timeout 500ms exceeded 

Test Suites: 1 failed, 1 total                            
Tests:       1 failed, 1 total                            
Snapshots:   0 total                                      
Time:        10.786s, estimated 11s                       
Ran all test suites.                                      

To Reproduce

Run tests. I am running them on a windows machine that may be an issue.

Expected behavior

Tests should fail.

Link to repl or repo (highly encouraged)

I am afraid I working in a corporate repo

Run npx envinfo --system --binaries --npmPackages expect-puppeteer,jest-dev-server,jest-environment-puppeteer,jest-puppeteer,spawnd --markdown --clipboard

Paste the results here:

## System:
 - OS: Windows 10
 - CPU: (8) x64 Intel(R) Core(TM) i5-8400H CPU @ 2.50GHz
 - Memory: 8.71 GB / 15.78 GB
## Binaries:
 - Node: 10.15.3 - C:\Program Files\nodejs\node.EXE
 - npm: 6.4.1 - C:\Program Files\nodejs\npm.CMD

[xiaoyuhen]

hi @dptoot

Could give me some information about the renders the page test code?

[dptoot]

@xiaoyuhen Thanks for getting back. Let me say first that with the exception of this issue jest-puppeteer has been great and simple to setup!

This is my initial setup of integration testing so there is not a lot going on.

I am running the suite on windows and it is part of a lerna based monorepo. The test setup is located
at the root level and the npm poc commands use lerna's scope to run the build/start commands within ./packages/poc dir

// ./jest.integration.config.js
module.exports = {
    preset: 'jest-puppeteer',
    testPathIgnorePatterns: [
        '\\\\node_modules\\\\',
        '<rootDir>/test/unit',
    ],
};

// ./jest-puppeteer.config.js
module.exports = {
    browserContext: 'incognito',
    launch: {
        headless: true,
        devtools: true,
    },
    server: {
        command: 'npm run poc:build && npm run poc:start',
        port: 3000,
        launchTimeout: 30000,
        debug: true,
    },
};

// ./test/integration/app.test.js
/* global page */

describe('app', () => {

    // Timeout needs to be increased to allow our page to initially navigate.
    // https://github.com/smooth-code/jest-puppeteer/issues/106#issuecomment-413344050
    beforeEach(async () => {
        jest.setTimeout(15000);
        await page.goto('http://localhost:3000');
    });

    afterEach(async () => {
        await new Promise(resolve => setTimeout(resolve, 550));
    });

    it('renders the page', async () => {
        expect(page).toMatch('Page Renders');
    });
});

Thanks for the help

[dptoot]

Closing this. Looks like the issue was on my side.
The expect methods needed an await to function correctly

 it('renders the page', async () => {
       await expect(page).toMatch('Page Renders');
 });

[gdanov]

for others landing here: often the cause for such exception is long-running test — just like the example above when test runs for longer than 5sec (the default wait time) jest gives up, does some clean-up (I guess) and you can see all sorts of promise rejection errors. Solution is to either specify longer timeout in the test itself

it('description', () => {}, 60000)

or somewhere before the test extend globally the timeout via jest.setTimeout(60000)