#prefer-snapshot-hint

#Configuration

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

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

#Rule Details

Prefer descriptive hints for external snapshots so their names explain what each snapshot captures. By default, hints are required when a group contains more than one external snapshot assertion. See Rstest snapshot naming.

The rule checks toMatchSnapshot, its matchSnapshot alias, and toThrowErrorMatchingSnapshot, including Chai assertion chains, expect.soft, and resolves/rejects. It recognizes globals, named and renamed imports, namespace imports, CommonJS imports, rstack/test, import.meta.rstest, and test-context expect, including parameterized and extended tests. The Rstest assertions exposed by @rstest/playwright are also checked. Locally shadowed or reassigned assertion bindings are ignored. Static bracket access and optional calls are recognized. Inline snapshots, file snapshots, static expect methods, negated snapshots, and expect.poll/expect.element chains are excluded. An assertion wrapped with as, satisfies, or a non-null assertion before the matcher access is not inspected.

Groups follow function expressions, arrow functions, methods, and accessors, including nested helper expressions. Each test or suite registration starts a new grouping boundary. Function declarations do not create a separate group, and helper calls are not followed to count runtime assertions. A hinted snapshot still contributes to its group's count.

For toMatchSnapshot and matchSnapshot, a single string literal or template literal counts as a hint; two arguments count as properties plus a hint. A single variable or other expression is treated as properties, even if its type is string. toThrowErrorMatchingSnapshot accepts one hint argument. The rule does not validate hint contents or argument types and does not require type information.

#Incorrect

import { expect, test } from '@rstest/core';

test('cart totals', () => {
  expect(cart.subtotal).toMatchSnapshot();
  expect(cart.total).toMatchSnapshot();
});

#Correct

import { expect, test } from '@rstest/core';

test('cart totals', () => {
  expect(cart.subtotal).toMatchSnapshot('before tax');
  expect(cart.total).toMatchSnapshot('after tax');
});

#Options

{
  "rstest/prefer-snapshot-hint": ["error", "always"]
}