No Module Mocking

Error

small-rules/no-module-mocking

Disallow Vitest and Jest module mocking; tests must replace dependencies through real interfaces.

Rationale

Ported from dmmulroy/anti-slop. Module mocks make tests depend on import machinery instead of the dependency seam the production code actually owns. Use a real interface, service layer, or faithful in-memory implementation.

Diagnostic Messages

moduleMock

Replace module mocking with dependency injection through a real interface, service layer, or faithful test implementation.

Configuration

This rule does not accept options.

{
  "jsPlugins": [
    "@pobammer-ts/small-rules"
  ],
  "rules": {
    "small-rules/no-module-mocking": "error"
  }
}

Examples

Vitest module mock

vi.mock('./user-store');

real test implementation

const store = new InMemoryUserStore();