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Forbid `g` flag used on `RegExp#test()`

See original GitHub issue

Got the idea from https://github.com/sindresorhus/eslint-plugin-unicorn/pull/1173

If the regex is only used once on RegExp#test(), the g flag is useless (~maybe also forbid y flag?~)

Fail

/foo/g.test(bar);

new RegExp('foo', 'g').test(bar);

Pass

const regex = /foo/g;
regex.test(bar);

I didn’t mark this issue as rule proposal, because I was thinking maybe we can add this to better-regex?

Issue Analytics

State:
Created 2 years ago
Reactions:4
Comments:5 (2 by maintainers)

Top GitHub Comments

1reaction

fiskercommented, Apr 9, 2021

Another possible problem in regex used to test. It should not capture group.

Fail

/(foo)/.test('foo')

/(?<named>foo)/.test('foo')

Pass

/([-_])foo\1/.test('_foo-')

/(?<separator>[-_])foo\k<separator>/.test('_foo-')

Update: This rule seems doing a better job.

1reaction

fiskercommented, Apr 9, 2021

I was wrong about y flag

/foo/.test('-foo');
true
/foo/y.test('-foo');
false

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