expect-expect
)Ensure that there is at least one expect
call made in a test.
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')); });
{ "jest/expect-expect": [ "error", { "assertFunctionNames": ["expect"] } ] }
assertFunctionNames
This array option specifies the names of functions that should be considered to be asserting functions. Function names can use wildcards i.e request.*.expect
, request.**.expect
, request.*.expect*
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(); });
Since the string is compiled into aa regular expression, you'll need to escape special characters such as $
with a double backslash:
/* eslint jest/expect-expect: ["error", { "assertFunctionNames": ["expect\\$"] }] */ it('is money-like', () => { expect$(1.0); });
Examples of correct code for working with the HTTP assertions library SuperTest with the { "assertFunctionNames": ["expect", "request.*.expect"] }
option:
/* eslint jest/expect-expect: ["error", { "assertFunctionNames": ["expect", "request.*.expect"] }] */ const request = require('supertest'); const express = require('express'); const app = express(); describe('GET /user', function () { it('responds with json', function (done) { request(app).get('/user').expect('Content-Type', /json/).expect(200, done); }); });