// Validate the single loadbalance.Selector.
func TestSelectFrom(t *testing.T) {
	cases := []struct {
		hosts []string
	}{
		{},                   // 0
		{[]string{}},         // 1
		{[]string{"a"}},      // 2
		{[]string{"a", "b"}}, // 3
	}
	for i, test := range cases {
		a := SelectFrom(test.hosts...)

		// Select returns the first host each time,
		// or empty if no hosts are defined.
		var expect string
		if len(test.hosts) > 0 {
			expect = test.hosts[0]
		}

		// 3 loops all return the same value
		for j := 0; j < 3; j++ {
			if got := a.Select(nil); got != expect {
				t.Errorf("[%d.%d] expected %s got %s", i, j, expect, got)
			}
		}
	}
}