HarnessPredicate doesn't correctly apply ancestor selectors to compound component selectors

[jelbourn]

Note(@jelbourn): Copied from an internal bug report

HarnessPredicate.getSelector returns the wrong result in certain cases. E.g., MatButtonHarness and other CDK harnesses are defined as matching one of several possible selectors:

  static hostSelector = [
    '[mat-button]',
    '[mat-raised-button]',
    '[mat-flat-button]',
    '[mat-icon-button]',
    '[mat-stroked-button]',
    '[mat-fab]',
    '[mat-mini-fab]',
  ].join(',');

I would expect getHarness(MatButtonHarness.with({ancestor: '.foo'})) to always find a MatButton that has a '.foo' ancestor. However, the current implementation of https://source.corp.google.com/search?q=HarnessPredicate.getSelector returns:

.foo [mat-button],[mat-raised-button],[mat-flat-button],[mat-icon-button],[mat-stroked-button],[mat-fab],[mat-mini-fab]

which only applies the ancestor constraint to the first possibility.

[angular-automatic-lock-bot]

This issue has been automatically locked due to inactivity.
Please file a new issue if you are encountering a similar or related problem.

Read more about our automatic conversation locking policy.

_{This action has been performed automatically by a bot.}