fix(Playwright): handle null context in proceedClick

[matthewjf]

Motivation/Description of the PR

We have a test that opens a link in a new tab, switches to that tab and tries to click a button. Some example code:

I.click(locate('.some-button'));
I.switchToNextTab();
I.waitForElement('Get Started');
I.retry(5).forceClick('Get Started');

and we get this error intermittently (maybe 50% of our runs):

     Cannot read property '$$' of null
      at Playwright.findElements (node_modules/codeceptjs/lib/helper/Playwright.js:2152:18)
      at Playwright.findClickable (node_modules/codeceptjs/lib/helper/Playwright.js:2186:47)
      at Playwright.proceedClick (node_modules/codeceptjs/lib/helper/Playwright.js:2162:35)

After some spelunking, we discovered that sometimes this.context gets set to null. No clue how that's happening as _setPage is meant to set the context and gets called when switching tabs. However, most methods in the file are using this._getContext() but I'm not sure what the semantic difference between it and this.context is.

Applicable helpers:

• WebDriver
• Puppeteer
• Nightmare
• REST
• FileHelper
• Appium
• Protractor
• TestCafe
• Playwright

Applicable plugins:

• allure
• autoDelay
• autoLogin
• customLocator
• pauseOnFail
• puppeteerCoverage
• retryFailedStep
• screenshotOnFail
• selenoid
• stepByStepReport
• wdio

Type of change

• 🔥 Breaking changes
• 🚀 New functionality
• 🐛 Bug fix
• 📋 Documentation changes/updates
• ♨️ Hot fix
• 🔨 Markdown files fix - not related to source code
• 💅 Polish code

Checklist:

• Tests have been added
• Documentation has been added (Run npm run docs)
• Lint checking (Run npm run lint)
• Local tests are passed (Run npm test)

[matthewjf]

Trying to understand this codebase a bit more, seems like this.context gets set when called using a within callback, so something like

  within('.some-selector', () => {
    I.click('Button');
  });

Wondering if we should be changing the implementation of _getContext to:

async _getContext() {
  return this.context || this.page;
}

or do a conditional check at the caller proceedClick:

let matcher = await this.context || await this._getContext();

or maybe dig deeper into why this.context is null?

Looking for some feedback.

[DavertMik]

Yeah, your solution should be fine

_getContext already checks that a context element is present.

As you found out that context is used for within to specify area for search. But there is another problem there, if inside within a new page is opened or context element removed this functionality won't work. Not even sure how to fix that :)

[DavertMik]

Sorry I missed the time to review it so now it was released as part of 3.0.3-beta
Please update to 3.0.3-beta to have this fix applied