How to lint for manual assertions?

[reckseba]

Hey community,

the best practices guide shows how to avoid using manual assertions:

// 👎
expect(await page.getByText('welcome').isVisible()).toBe(true);

Use web first assertions such as toBeVisible() instead.

// 👍
await expect(page.getByText('welcome')).toBeVisible();

Regarding the available list of rules, I might be missing on linting for that or am I overlooking something?

Thank you, sincerely
Sebastian

[mskelton]

Already supported with https://github.com/playwright-community/eslint-plugin-playwright/blob/main/docs/rules/prefer-web-first-assertions.md

[reckseba]

Mh okay thanks you are right. I overlooked it because it's active by default and does not complain on the following:
expect(await page.getByText('First thing').innerHTML()).toContain('Second thing') . How come?

[mskelton]

Because expect(await page.getByText('First thing').innerHTML()).toContain('Second thing') is a ridiculous assertion that no one should ever write.

Time to introduce RIDICULOUS_SELECTOR_DO_NOT_USE_OR_YOU_WILL_BE_FIRED like React's internals.

I honestly don't care to support that, nor does it make sense. Why would you ever use innerHTML? There is nothing we can do with that, since toContain('<div') isn't saying it has text, that's literally saying the HTML has a div tag in it.

[reckseba]

I don't and that's why I want to setup the linting to avoid somebody doing it.

[mskelton]

You can use https://eslint.org/docs/latest/rules/no-restricted-syntax to prevent specific stuff if you want.