jest/prefer-jest-mocked Style

🛠️ An auto-fix is available for this rule for some violations.

What it does

When working with mocks of functions using Jest, it's recommended to use the jest.mocked() helper function to properly type the mocked functions. This rule enforces the use of jest.mocked() for better type safety and readability.

Restricted types:

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

Examples

// invalid
(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);

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

References

• Rule Source