Allow this in property and call descendants in render assignments

[bearfriend]

A ThisExpression that is the descendant of a property or call within an assignment should not trigger assignmentFound

[43081j]

Are you trying to catch these two cases?

this.foo.bar = 123;

fn(this).bar = 123;

I feel like the pattern will be too specific right now. It'll probably be easier to maintain if we keep the same pattern but update the rule logic

Also, both of these mean you're mutating something in your render method, which is what this rule is meant to prevent

Could you give a real world example of why someone might need this?

[dlockhart]

Could you give a real world example of why someone might need this?

From our recent lock file update to get these changes (which because of the better Lit element detection in the latest release is now finally applying these rules to some of our elements):

This failed:

render() {
  const secondaryPanelStyles = {};
  if (this._isResizable()) {
    secondaryPanelStyles[this._isMobile ? 'height' : 'width'] = `${size}px`;
  }
}

And had to become:

render() {
  const secondaryPanelStyles = {};
  if (this._isResizable()) {
    const dimension = this._isMobile ? 'height' : 'width';
    secondaryPanelStyles[dimension] = `${size}px`;
  }
}

So no mutation of anything on "this" in the render.

[bearfriend]

@dlockhart laid out our real world example of the .property descendant case (thanks!). The CallExpression case is as you guessed:

fn(this).bar = 123;

This mutates something but it doesn't mutate this.

I'm not terribly familiar with eslint plugins but I can take a stab at converting my selector changes to rule logic, though I would think it's pretty stable as it seems like these are the only two ways you can get a ThisExpression as a descendant of an AssignmentExpression that shouldn't error.

[bearfriend]

Closing in favor of #214