boolean-literal-compare.test.ts

import path from 'path';

import rule from '../../src/rules/boolean-literal-compare';
import { RuleTester } from '../RuleTester';

const rootPath = path.join(process.cwd(), 'tests/fixtures/');

const ruleTester = new RuleTester({
  parser: '@typescript-eslint/parser',
  parserOptions: {
    tsconfigRootDir: rootPath,
    project: './tsconfig.json',
  },
});

ruleTester.run('boolean-literal-compare', rule, {
  valid: [
    '3 > 4;',
    '4 < 7;',
    '3 == 4;',
    '4 === 3;',
    '7 !== 4;',
    '({} === {});',
    '({} === 3);',
    '(3 !== {});',
    '({} > {});',
    '({} > 3);',
    '(3 > {});',
    `
declare const varAny: any;
varAny === 'true';
varAny === 'true';
`,
    `
declare const varString: string;
declare const varObject: {};
'false' === varString;
varObject == varString;
'true' === varObject;
`,
    '[] !== {};',
    `(() => "")() == (() => "");`,
    `
let union: {} | boolean;

union === true;
union === false;
`,
    `
let union: ({} | {}) | boolean;

union === true;
union === false;
`,
    `
let union: { option: any } | boolean;

union === false;
`,
    `
let union: [] | boolean;

union === true;
`,
    `
let union: boolean | undefined;

union === true;
`,
    `
    let union: (boolean | boolean) | undefined;

union === true;
`,
    `
let union: (boolean | {}) | undefined;

union === true;
`,
    `
let union: (boolean | {}) | false;

union === true;
`,
  ],

  invalid: [
    {
      code: `
true === true;
true !== true;
true === false;
true !== false;
false === true;
false !== true;
false === false;
false !== false;
`,
      errors: [
        {
          line: 2,
          messageId: 'direct',
        },
        {
          line: 3,
          messageId: 'direct',
        },
        {
          line: 4,
          messageId: 'negated',
        },
        {
          line: 5,
          messageId: 'negated',
        },
        {
          line: 6,
          messageId: 'direct',
        },
        {
          line: 7,
          messageId: 'direct',
        },
        {
          line: 8,
          messageId: 'negated',
        },
        {
          line: 9,
          messageId: 'negated',
        },
      ],
    },
    {
      code: `
(() => "")() == true;
(() => "")() == false;
(() => "")() === true;
(() => "")() === false;
`,
      errors: [
        {
          line: 2,
          messageId: 'direct',
        },
        {
          line: 3,
          messageId: 'negated',
        },
        {
          line: 4,
          messageId: 'direct',
        },
        {
          line: 5,
          messageId: 'negated',
        },
      ],
    },
    {
      code: `
true == [];
true != [];
false == {};
false != {};
`,
      errors: [
        {
          line: 2,
          messageId: 'direct',
        },
        {
          line: 3,
          messageId: 'negated',
        },
        {
          line: 4,
          messageId: 'negated',
        },
        {
          line: 5,
          messageId: 'direct',
        },
      ],
    },
    {
      code: `
declare const varBoolean: boolean;
declare const varTrue: true;
declare const varFalse: false;

varBoolean === false;
varBoolean !== false;
varBoolean === true;
varBoolean !== true;
varTrue === false;
varTrue !== false;
varFalse === true;
varFalse !== true;
false === varTrue;
false !== varTrue;
true === varTrue;
true !== varTrue;
`,
      errors: [
        {
          line: 6,
          messageId: 'negated',
        },
        {
          line: 7,
          messageId: 'negated',
        },
        {
          line: 8,
          messageId: 'direct',
        },
        {
          line: 9,
          messageId: 'direct',
        },
        {
          line: 10,
          messageId: 'negated',
        },
        {
          line: 11,
          messageId: 'negated',
        },
        {
          line: 12,
          messageId: 'direct',
        },
        {
          line: 13,
          messageId: 'direct',
        },
        {
          line: 14,
          messageId: 'negated',
        },
        {
          line: 15,
          messageId: 'negated',
        },
        {
          line: 16,
          messageId: 'direct',
        },
        {
          line: 17,
          messageId: 'direct',
        },
      ],
    },
  ],
});