Fibonacci in Go

fibonacci_test.go

func TestFibonacci(t *testing.T) {
	f := func(n int) (r int) {
		a, b := 0, 1
		for i := 2; i <= n; i++ {
			b, a = a+b, b
		}
		return b
	}

	table := []int{1, 3, 8, 13, 21}
	res := []int{1, 2, 21, 233, 10946}
	//or check if n is a Fibonacci number if and only if either 5n^2 + 4 or 5n^2 - 4 is a perfect square.

	for i, n := range table {
		r := f(n)
		if r != res[i] {
			t.Errorf("wrong results got %v want %v", r, res[i])
		}
	}
}