Bug: [new config system] Patterns cannot re-ignore #16416

Environment

Node version: v16.14.0
npm version: v8.3.1
Local ESLint version: main branch
Global ESLint version: Not found
Operating System: win32 10.0.19044

What parser are you using?

Default (Espree)

What did you do?

my-app/
├── a.js
└── eslint.config.js

// eslint.config.js
module.exports = [{
  ignores: [
      "*.js",
      "!a*.js",
      "a.js"
  ]
}];

Command:

eslint a.js -f tap

What did you expect to happen?

I'd expect a.js to be ignored. It should be possible to re-ignore previously unignored files. In other words, the last pattern that matches the file should determine whether the file is ignored: if it's non-negative then the file is ignored, if it's negative then the file is not ignored,

(unless the file is in an ignored directory, in which case the file is ignored regardless of patterns that match the file itself).

What actually happened?

TAP version 13
1..1
ok 1 - D:\tmp\my-app\a.js

Participation

• I am willing to submit a pull request for this issue.

Additional comments

The same applies to directories. I believe that the code that determines whether a directory is ignored should be the same as the code that determines whether a file is ignored by ignore patterns, except that we should make sure that the directory path ends with a / so that it can match with patterns that end with /.