Write Lint Checks for the End-to-End Tests

This issue is on hold while @ShivamJhaa completes the E2E migration.

To improve the quality of our end-to-end testing code, we want to create lint checks for common bad practices. If you would like to help with this issue, please leave a comment on this issue with the task you want to work on.

How to Write E2E Lint Checks

1. First think about how you can identify the bad practice based solely on the text of the code. Imagine you get a code file as a string. How would you look for any cases of the practice you are writing a check against? While you won’t know the types of variables in the code, you can take advantage of linters’ abstract syntax trees representing the parsed code. Note that you might conclude it’s not possible to enforce a practice with a linter. For example, we discovered that with action.clear. If this happens, please let us know so we can remove it from the list.
2. Follow the instructions on the linter wiki page for adding a new lint check. Since you’re linting the E2E code, you’ll want to write a custom ESLint check. You’ll probably do something like this:
   • Write the code for your check as a new file in scripts/linters/custom_eslint_checks/rules/.
   • Write a corresponding *.spec.js file to test your code.
   • Add your rule to to the object with oppia/e2e-action in overrides of .eslintrc
3. Remove the node_modules/eslint-plugin-oppia/ directory and run yarn install to install your linter.
4. Run python -m scripts.run_custom_eslint_tests to check that the tests you wrote pass.
5. Run your lint checks with:

   python -m scripts.linters.pre_commit_linter --path core/tests/protractor
   python -m scripts.linters.pre_commit_linter --path core/tests/protractor_desktop
   python -m scripts.linters.pre_commit_linter --path core/tests/protractor_utils
   

   and fix any errors.
6. Create a PR to add your lint check!

You can also check out #11734 as an example of how to add these checks. If you have any questions, please reach out to @U8NWXD.

Lint Checks to Add

• Use action.click instead of calling .click() on an element. @U8NWXD
• Use action.sendKeys instead of calling .sendKeys on an element. @U8NWXD
• Do not access pages by URLs.
• Do not call .first() on a list of ElementArrayFinders. Reserved for GSoC
• Do not call .last() on a list of ElementArrayFinders. Reserved for GSoC
• Do not call .get() on a list of ElementArrayFinders. Reserved for GSoC
• Do not use browser.sleep() calls @AdityaDubey0
• Usernames, email addresses, topic names, skill names, exploration names, story names, and chapter names should be reliably unique as described in the wiki.
• Do not index into ElementArrayFinders with bracket notation ([]).
• Do not access .length of ElementArrayFinders.
• Do not use browser.switchTo().activeElement(). There might be some exceptions.
• Make sure to have nested awaits for await (await browser.switchTo().activeElement()).sendKeys(explanation);. There should be no exceptions to this.
• Do not use forEach. @vashuteotia123
• Do not use filter.
• Do not use .then(). @MA86

Notes

• It isn’t possible to write a lint check for using action.clear instead of calling .clear() on an element. This is because it’s valid to call .clear() on rich text editors.

[abderrahmaneMustapha]

hi @U8NWXD iwas busy this week but i can start working on this tomorrow

[U8NWXD]

Deassigned @suryasiriki4 @ahreehong @iabouara24 @SAEb-ai @Varun8216889 @MA86 due to inactivity. If you are still working on your tasks, let me know and I’ll re-assign you