#prefer-jest-mocked

#Configuration

import { defineConfig, jestPlugin } from '@rslint/core';

export default defineConfig([
  jestPlugin.configs.recommended,
  {
    rules: {
      'jest/prefer-jest-mocked': 'error',
    },
  },
]);

#Rule Details

Prefer jest.mocked() over type assertions such as fn as jest.Mock when working with mocked functions in Jest. The jest.mocked() helper preserves correct mock typings without manual casts, which improves type safety and keeps mock setup easier to read.

This rule reports type assertions and angle-bracket casts to Jest mock types, including chained assertions like as unknown as jest.Mock. It is fixable.

Restricted types:

• jest.Mock
• jest.MockedFunction
• jest.MockedClass
• jest.MockedObject

Examples of incorrect code for this rule:

(foo as jest.Mock).mockReturnValue(1);
const mock = (foo as jest.Mock).mockReturnValue(1);
(foo as unknown as jest.Mock).mockReturnValue(1);
(Obj.foo as jest.Mock).mockReturnValue(1);
([].foo as jest.Mock).mockReturnValue(1);

Examples of correct code for this rule:

jest.mocked(foo).mockReturnValue(1);
const mock = jest.mocked(foo).mockReturnValue(1);
jest.mocked(Obj.foo).mockReturnValue(1);
jest.mocked([].foo).mockReturnValue(1);

#Original Documentation

• jest/prefer-jest-mocked