How to test panics?

Question

I\'m currently pondering how to write tests that check if a given piece of code panicked? I know that Go uses recover to catch panics, but unlike say, Java code, you can\'t

Answer 1

Succinct Way

To me, the solution below is easy to read and shows a maintainer the natural code flow under test.

func TestPanic(t *testing.T) {
    // No need to check whether `recover()` is nil. Just turn off the panic.
    defer func() { recover() }()

    OtherFunctionThatPanics()

    // Never reaches here if `OtherFunctionThatPanics` panics.
    t.Errorf("did not panic")
}

---

For a more general solution, you can also do it like this:

func TestPanic(t *testing.T) {
    shouldPanic(t, OtherFunctionThatPanics)
}

func shouldPanic(t *testing.T, f func()) {
    defer func() { recover() }()
    f()
    t.Errorf("should have panicked")
}