#no-restricted-matchers

#Configuration

import { defineConfig, rstestPlugin } from '@rslint/core';

export default defineConfig([
  rstestPlugin.configs.recommended,
  {
    rules: {
      'rstest/no-restricted-matchers': 'error',
    },
  },
]);

#Rule Details

Disallow selected matcher or modifier chains in Rstest assertions. This lets a project steer tests away from matchers that are ambiguous, too broad, or inconsistent with its assertion conventions, with an optional message that names the preferred alternative.

The rule recognizes global and imported expect, renamed and namespace imports, CommonJS imports, import.meta.rstest, and the expect provided by a test's TestContext. It also recognizes expect.soft, expect.poll, expect.element, static expect APIs, and Chai-style language chains and property or call matchers. Local shadows and assertion functions from other frameworks are ignored. The rule does not require type information.

For a Chai chain containing multiple assertions, only the chain through the first matcher is checked. For example, to.be.a can restrict expect(value).to.be.a('string').and.contain('x'), while contain cannot. Dynamic computed members such as expect(value)[matcher]() are ignored because their names are not known statically.

#Incorrect

test('returns the complete account', () => {
  expect(loadAccount()).toEqual({ id: 1, name: 'Ada' });
});

#Correct

test('returns the complete account', () => {
  expect(loadAccount()).toStrictEqual({ id: 1, name: 'Ada' });
});

#Options

{
  "rstest/no-restricted-matchers": [
    "error",
    {
      "toEqual": "Use toStrictEqual for object comparisons.",
      "resolves.not": null
    }
  ]
}

The option object maps a matcher or modifier chain to a custom diagnostic message, or to null for the default message. Ordinary chains require an exact match. A single not, resolves, or rejects entry matches any chain beginning with that modifier, and a chain ending in .not also matches by prefix.

When several entries match, the chain with more segments wins; chains of equal length are ordered alphabetically. Only one diagnostic is reported for each assertion.