#valid-title

#Configuration

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

export default defineConfig([
  rstestPlugin.configs.recommended,
  {
    rules: {
      'rstest/valid-title': 'error',
    },
  },
]);

#Rule Details

Enforce valid titles on Rstest describe, test, and it blocks. Titles should be informative strings, follow project conventions you configure, and use only the printf-style placeholders that Rstest actually expands in array-based .each / .for titles.

This rule checks that titles are:

• not empty (including empty template literals),
• string literals (unless relaxed via options),
• not accidentally prefixed with the block keyword (for example test('test foo')),
• free of leading or trailing whitespace (unless ignoreSpaces is enabled),
• using only valid printf specifiers for array-based .each / .for table names,
• not matching disallowedWords (whole-word, case-insensitive) when that option is set,
• satisfying mustMatch / mustNotMatch patterns when configured (per describe / test / it or a single global pattern).

Auto-fix is available for accidental surrounding spaces and duplicate keyword prefixes.

emptyTitle

Examples of incorrect code:

describe('', () => {});
it('', () => {});
test('', () => {});

Examples of correct code:

describe('suite', () => {});
it('does something', () => {});
test('works', () => {});

titleMustBeString

Use string literals for titles unless ignoreTypeOfDescribeName or ignoreTypeOfTestName is true.

Examples of incorrect code:

it(123, () => {});
describe(myFunction, () => {});

Examples of correct code:

it('is a string', () => {});
describe('suite', () => {});

invalidEachSpecifier

Titles of array-based .each and .for registrations are formatted at runtime. After a single %, only s, d, j, i, f, o, O, c, #, and $ are accepted, and %% denotes a literal percent.

Examples of incorrect code:

test.each([[1, 2]])('.add(%I, %I)', (a, b) => {
  expect(a + b).toBe(3);
});

Examples of correct code:

test.each([[1, 2]])('.add(%i, %i)', (a, b) => {
  expect(a + b).toBe(3);
});

Tagged-template tables are not checked, because they interpolate with $name rather than printf specifiers and a bare % in them is literal text:

test.each`
  a    | b
  ${1} | ${2}
`('returns $a and $b', ({ a, b }) => {});

duplicatePrefix

Examples of incorrect code:

test('test foo', () => {});
it('it foo', () => {});
describe('describe foo', () => {
  it('bar', () => {});
});

Examples of correct code:

test('foo', () => {});
it('foo', () => {});
describe('foo', () => {
  it('bar', () => {});
});

accidentalSpace

Examples of incorrect code:

test(' foo', () => {});
it('foo ', () => {});

Examples of correct code:

test('foo', () => {});
it('foo', () => {});

#Differences from jest/valid-title

The rule is otherwise a port of jest/valid-title, with three differences that follow from how Rstest itself behaves.

The set of valid printf specifiers is Rstest's, not Jest's. Rstest formats parameterized titles with Node's util.format semantics, accepting s, d, j, i, f, o, O, c, and % after a %, while Jest uses its own pretty-format placeholder set. So:

.for titles are checked too. Rstest has both .each and .for, and both format their titles the same way. Jest has no .for.

There are no f / x prefixed aliases. Rstest provides no fit, xit, xtest, fdescribe, or xdescribe, so the keyword compared against the title is always the API being registered — test, it, or describe — even when it was imported or aliased under another name. import { it as xit } from '@rstest/core'; xit('it works', fn) is reported, and mustMatch: { test: … } applies to import { test as check } …; check(…).

#Options

interface Options {
  ignoreSpaces?: boolean;
  ignoreTypeOfDescribeName?: boolean;
  ignoreTypeOfTestName?: boolean;
  disallowedWords?: string[];
  mustNotMatch?: Partial<Record<'describe' | 'test' | 'it', string>> | string;
  mustMatch?: Partial<Record<'describe' | 'test' | 'it', string>> | string;
}

• ignoreSpaces (default false): skip leading/trailing space checks.
• ignoreTypeOfDescribeName / ignoreTypeOfTestName (default false): allow non-string first arguments for describe or test/it respectively.
• disallowedWords: list of words that must not appear as whole words in titles (case-insensitive).
• mustMatch / mustNotMatch: ECMAScript regular expressions as strings, either one pattern for all block kinds or an object keyed by describe, test, and it. You can pass a two-element array [pattern, customMessage] to surface *Custom message variants.

#Original Documentation

• jest/valid-title