#no-standalone-expect

#Configuration

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

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

#Rule Details

Disallow using expect outside of it or test blocks. This rule reports expect calls that sit directly in a describe block, at module scope, or in other places where Rstest will not run them as part of a test case. This helps catch assertions that look meaningful but never execute as part of a test.

expect inside a helper function is allowed, even when the helper is defined outside the it/test callback, because the assertion still runs when the helper is invoked from a test. Static expect APIs such as expect.any() and expect.extend() at module scope are also allowed.

Only the callback body of a registration counts as the test case. A test's name, its options object and any other argument are evaluated while Rstest collects the file, so an assertion written there runs before any case starts and is reported — including on a registration that takes no callback at all, such as test.todo(expect(1).toBe(1)). A tagged-template registration is the exception: test.each`...`(name, callback) counts as a test block in its entirety, so an assertion in an interpolation or in an argument of the call the tag returns is allowed.

Examples of incorrect code for this rule:

describe('a test', () => {
  expect(1).toBe(1);
});

describe('a test', () => {
  test('a test case', () => {
    expect(1).toBe(1);
  });

  expect(1).toBe(1);
});

expect(1).toBe(1);
expect.hasAssertions();

test.todo(expect(1).toBe(1));

test('a test case', { timeout: expect(1).toBe(1) }, () => {});

Examples of correct code for this rule:

describe('a test', () => {
  test('a test case', () => {
    expect(1).toBe(1);
  });
});

describe('a test', () => {
  const helper = () => {
    expect(1).toBe(1);
  };

  test('a test case', () => {
    helper();
  });
});

expect.any(String);
expect.extend({});

#Options

• First argument (optional): object with additionalTestBlockFunctions
  • additionalTestBlockFunctions: array of function names that should also be treated as test blocks (for example each.test).