Change Request: Rule Tester omit specific properties for duplicate test case detection

[DMartens]

ESLint version

8.57.0

What problem do you want to solve?

The RuleTester currently stringifies all test case properties for each test case to check for duplicate test cases (see here).
This means some duplicate test cases are not discovered.
Test cases with different names:

ruleTester.run('rule', rule, {
	valid: [
		{ code: 'code' },
		{ name: 'name', code: 'code' },
	],
	invalid: [],
}),

Test cases with a different error matcher:

ruleTester.run('rule', rule, {
	valid: [],
	invalid: [	
		{ code: 'code', errors: 1 },
		{ code: 'code', errors: [{ messageId: 'id' }] },
	],
}

Not fixable test cases one specifying output and the other not:

ruleTester.run('rule', rule, {
	valid: [],
	invalid: [	
		{ code: 'code', errors: 1, output: null },
		{ code: 'code', errors: 1 },
	],
}

What do you think is the correct solution?

The used serialize package offers a replacer method which could exclude the properties name, errors and output.
The other Rule Tester specific property is only but I do not think that developers want to be warned about duplicate test cases when focusing on a test case.

Participation

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

Additional comments

No response

[nzakas]

Ah, good catch! This seems like a bug to me. The goal of duplicate test detection is to make sure you're not running the rule on the same code using the same options multiple times, and we're clearly not doing that. Marking as accepted.

[bmish]

Makes sense to fix this.