eslint-plugin-jest/lib/rules/__tests__/prefer-to-be-undefined.test.js

Eslint rules for Jest

'use strict';

const _require = require('eslint'),
      RuleTester = _require.RuleTester;

const rule = require('../prefer-to-be-undefined');

const ruleTester = new RuleTester();
ruleTester.run('prefer-to-be-undefined', rule, {
  valid: ['expect(undefined).toBeUndefined();', 'expect(true).not.toBeUndefined();', 'expect({}).toEqual({});', 'expect(null).toEqual(null);', 'expect(something).toBe(somethingElse)', 'expect(something).toEqual(somethingElse)', 'expect(something).not.toBe(somethingElse)', 'expect(something).not.toEqual(somethingElse)', 'expect(undefined).toBe'],
  invalid: [{
    code: 'expect(undefined).toBe(undefined);',
    errors: [{
      messageId: 'useToBeUndefined',
      column: 19,
      line: 1
    }],
    output: 'expect(undefined).toBeUndefined();'
  }, {
    code: 'expect(undefined).toEqual(undefined);',
    errors: [{
      messageId: 'useToBeUndefined',
      column: 19,
      line: 1
    }],
    output: 'expect(undefined).toBeUndefined();'
  }, {
    code: 'expect("a string").not.toBe(undefined);',
    errors: [{
      messageId: 'useToBeUndefined',
      column: 24,
      line: 1
    }],
    output: 'expect("a string").not.toBeUndefined();'
  }, {
    code: 'expect("a string").not.toEqual(undefined);',
    errors: [{
      messageId: 'useToBeUndefined',
      column: 24,
      line: 1
    }],
    output: 'expect("a string").not.toBeUndefined();'
  }]
});