Can you mock methods with parameters? How?

Short answer: mockService.Setup(s => s.GetData(It.IsAny<int>())).Returns("Data"); You can specify argument matchers like It.IsAny<T>() to mock methods with parameters.

Explain a bit more

mockService.Setup(s => s.GetData(It.IsAny<int>())).Returns("Data"); You can specify argument matchers like It.IsAny<T>() to mock methods with parameters. mockService.Setup(s => s.GetData(It.IsAny<int>())).Returns("Data"); You can specify argument matchers like It.IsAny<T>() to mock methods with parameters. mockService.Setup(s => s.GetData(It.IsAny<int>())).Returns("Data"); You can specify argument matchers like It.IsAny<T>() to mock methods with parameters.

Real-world example (ShopNest)

When testing ShopNest’s order service, mock IPaymentGateway so tests do not call Razorpay.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.