How do I test different error types in Go?

How do I test different error types in Go?

In Go, you can use the errors package to create custom error types. You can then use type assertions in your tests to check for specific error types.

Can you show me an example of a custom error type?

Sure! Here's a simple example:

type MyError struct {
    Message string
}

func (e *MyError) Error() string {
    return e.Message
}

You can then create an instance of MyError and return it from a function.

How do I test if a function returns this custom error?

You can use the errors.As function in your test to check if the error is of type MyError. Here's an example:

var myErr *MyError
if errors.As(err, &myErr) {
    // Handle the custom error
}

What if I want to test multiple error types?

You can use a switch statement or multiple type assertions to handle different error types in your tests.