表测试多返回值功能

Question

I'm cutting my teeth on Go and after digging into table driven tests I ran into the following problem:

I have a function that returns multiple values

// Halves an integer and and returns true if it was even or false if it was odd.
func half(n int) (int, bool) {
    h := n / 2
    e := n%2 == 0
    return h, e
}

I know that for half(1) the return value should be 0, false and for half(2) it should match 1, true, but I can't seem to figure out how to put this on a table.

How would one go to have something that resembles the following?

var halfTests = []struct {
    in  int
    out string
}{
    {1, <0, false>},
    {3, <1, true>},
}

Is there any other, more idiomatic way of doing this?

For reference, here's a test for something that resembles a FizzBuzz function, using tables:

var fizzbuzzTests = []struct {
    in  int
    out string
}{
    {1, "1"},
    {3, "Fizz"},
    {5, "Buzz"},
    {75, "FizzBuzz"},
}

func TestFizzBuzz(t *testing.T) {
    for _, tt := range fizzbuzzTests {
        s := FizzBuzz(tt.in)
        if s != tt.out {
            t.Errorf("Fizzbuzz(%d) => %s, want %s", tt.in, s, tt.out)
        }
    }
}

Answer 1

Just add another field to your struct that holds the second return value. Example:

var halfTests = []struct {
    in   int
    out1 int
    out2 bool
}{
    {1, 0, false},
    {3, 1, true},
}

Your testing function would look like the following:

func TestHalf(t *testing.T) {
    for _, tt := range halfTests {
        s, t := half(tt.in)
        if s != tt.out1 || t != tt.out2 {
            t.Errorf("half(%d) => %d, %v, want %d, %v", tt.in, s, t, tt.out1, tt.out2)
        }
    }
}