Add the possibility to ignore some constructors in no-new

What rule do you want to change?

no-new

Does this change cause the rule to produce more or fewer warnings?

• fewer

How will the change be implemented? (New option, new default behavior, etc.)?

• By default all side-effect usages of new will be reported, like now
• You have the possibility to add constructors to an option, which will then be allowed.

Like:

no-new:
  - error
  - ignore:
      - Vue

Please provide some example code that this change will affect:

We often initialize Vue components with this pattern:

import Component from './components/component';

document.addEventListener('DOMContentLoaded', () => {
  const element = document.getElementById('id');
  new Vue({
    el: element,
    components: {
      Component,
    },
    render(createElement) {
      return createElement('component', {
        props: { ...element.dataset },
      });
    },
   })
})

See our open issues here:

• https://gitlab.com/gitlab-org/gitlab-ce/issues/42783
• https://gitlab.com/gitlab-org/gitlab-ce/issues/42306

What does the rule currently do for this code?

Throw an error. There are several workarounds for this, that are not nice:

1. add eslint-disable, this really adds up if you have a lot of components.
2. return the result of new Vue in the function, but this makes no sense, as no function caller is actually using it

What will the rule do after it’s changed?

Throw no new error.

[platinumazure]

@eslint/eslint-team This needs a champion and one more 👍, thanks!

[platinumazure]

I could get behind this.

Should we support ignoring just constructor identifier names? I feel it could be a bit more flexible if we instead allowed users to specify AST selectors which we would match against the callee nodes of the NewExpression.

Examples with AST selectors:

• [name='Vue'] (ignores new Vue())
• [object.name='Backbone'] (ignores new Backbone.foo() for any foo)

But the trade-off is that the rule configuration has a little steeper learning curve.