github-pages-deploy-action/node_modules/eslint-plugin-jest/docs/rules/expect-expect.md
2020-03-06 22:45:40 -05:00

1.6 KiB

Enforce assertion to be made in a test body (expect-expect)

Ensure that there is at least one expect call made in a test.

Rule details

This rule triggers when there is no call made to expect in a test, to prevent users from forgetting to add assertions.

Examples of incorrect code for this rule:

it('should be a test', () => {
  console.log('no assertion');
});
test('should assert something', () => {});

Examples of correct code for this rule:

it('should be a test', () => {
  expect(true).toBeDefined();
});
it('should work with callbacks/async', () => {
  somePromise().then(res => expect(res).toBe('passed'));
});

Options

{
  "jest/expect-expect": [
    "error",
    {
      "assertFunctionNames": ["expect"]
    }
  ]
}

assertFunctionNames

This array option whitelists the assertion function names to look for.

Examples of incorrect code for the { "assertFunctionNames": ["expect"] } option:

/* eslint jest/expect-expect: ["error", { "assertFunctionNames": ["expect"] }] */

import { expectSaga } from 'redux-saga-test-plan';
import { addSaga } from '../src/sagas';

test('returns sum', () =>
  expectSaga(addSaga, 1, 1)
    .returns(2)
    .run();
);

Examples of correct code for the { "assertFunctionNames": ["expect", "expectSaga"] } option:

/* eslint jest/expect-expect: ["error", { "assertFunctionNames": ["expect", "expectSaga"] }] */

import { expectSaga } from 'redux-saga-test-plan';
import { addSaga } from '../src/sagas';

test('returns sum', () =>
  expectSaga(addSaga, 1, 1)
    .returns(2)
    .run();
);