Catching panics in Golang

Question

With the following code, if no file argument is given, a panic is thrown for line 9 panic: runtime error: index out of range as expected.

How can I \'catch\

Answer 1

I had to catch panics in a test case. I got redirected here.

func.go

var errUnexpectedClose = errors.New("Unexpected Close")
func closeTransaction(a bool) {
    if a == true {
        panic(errUnexpectedClose)
    }
}

func_test.go

func TestExpectedPanic() {
    got := panicValue(func() { closeTransaction(true) })
    a, ok := got.(error)
    if a != errUnexpectedClose || !ok {
        t.Error("Expected ", errUnexpectedClose.Error())
    }
}

func panicValue(fn func()) (recovered interface{}) {
    defer func() {
        recovered = recover()
    }()
    fn()
    return
}

Used from https://github.com/golang/go/commit/e4f1d9cf2e948eb0f0bb91d7c253ab61dfff3a59 (ref from VonC)