jest/prefer-jest-mocked Style
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
typescript
// 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);
How to use
To enable this rule in the CLI or using the config file, you can use:
bash
oxlint --deny jest/prefer-jest-mocked --jest-plugin
json
{
"plugins": ["jest"],
"rules": {
"jest/prefer-jest-mocked": "error"
}
}