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

Eslint rules for Jest

'use strict';

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

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

const ruleTester = new RuleTester();
ruleTester.run('prefer-to-be-null', rule, {
  valid: ['expect(null).toBeNull();', 'expect(null).toEqual();', 'expect(null).not.toBeNull();', 'expect(null).not.toEqual();', 'expect(null).toBe(undefined);', 'expect(null).not.toBe(undefined);', 'expect(null).toBe();', 'expect(null).toMatchSnapshot();', 'expect("a string").toMatchSnapshot(null);', 'expect("a string").not.toMatchSnapshot();', "expect(something).toEqual('a string');", 'expect(null).toBe'],
  invalid: [{
    code: 'expect(null).toBe(null);',
    errors: [{
      messageId: 'useToBeNull',
      column: 14,
      line: 1
    }],
    output: 'expect(null).toBeNull();'
  }, {
    code: 'expect(null).toEqual(null);',
    errors: [{
      messageId: 'useToBeNull',
      column: 14,
      line: 1
    }],
    output: 'expect(null).toBeNull();'
  }, {
    code: 'expect("a string").not.toBe(null);',
    errors: [{
      messageId: 'useToBeNull',
      column: 24,
      line: 1
    }],
    output: 'expect("a string").not.toBeNull();'
  }, {
    code: 'expect("a string").not.toEqual(null);',
    errors: [{
      messageId: 'useToBeNull',
      column: 24,
      line: 1
    }],
    output: 'expect("a string").not.toBeNull();'
  }]
});