resolver_test.go

package main

import (
	"net"
	"testing"
)

func assertLookupEquals(t *testing.T, got []net.IP, want []net.IP) {
	if len(got) != len(want) {
		t.Errorf("len(Lookup(dest)) != %d; want %d", len(got), len(want))
	}
	for _, wantResult := range want {
		assertIpInResult(t, got, wantResult)
	}
}

func assertIpInResult(t *testing.T, got []net.IP, want net.IP) bool {
	for _, gotResult := range got {
		if gotResult.String() == want.String() {
			return true
		}
	}
	t.Errorf("Lookup(dest) = %s; missing %s", got, want)
	return false
}

func assertLenOfResultsInRange(t *testing.T, got []net.IP, wantMin int, wantMax int) {
	if wantMin > wantMax {
		t.Errorf("wantMin (%d) must be less than or equal to wantMax (%d)", wantMin, wantMax)
	} else if len(got) < wantMin {
		t.Errorf("len(Lookup(dest)) = %s; want >= %d", got, wantMin)
	} else if len(got) > wantMax {
		t.Errorf("len(Lookup(dest)) = %s; want <= %d", got, wantMax)
	}
}

func TestLookupLoopbackIp(t *testing.T) {
	dest, err := NewDestination(Url{Label: "localhost", Url: "http://127.0.0.1"})
	assertNoError(t, dest, err)
	got, err := Lookup(dest)
	assertNoError(t, dest, err)
	assertLookupEquals(t, got, []net.IP{net.ParseIP("127.0.0.1")})
}

func TestLookupPublicIp(t *testing.T) {
	dest, err := NewDestination(Url{Label: "google_dns", Url: "http://8.8.8.8"})
	assertNoError(t, dest, err)
	got, err := Lookup(dest)
	assertNoError(t, dest, err)
	assertLookupEquals(t, got, []net.IP{net.ParseIP("8.8.8.8")})
}

func TestLookupExample(t *testing.T) {
	dest, err := NewDestination(Url{Label: "example", Url: "https://example.com"})
	assertNoError(t, dest, err)
	got, err := Lookup(dest)
	assertNoError(t, dest, err)
	assertLenOfResultsInRange(t, got, 1, 10)
}

func TestLookupInvalidHostname(t *testing.T) {
	dest, err := NewDestination(Url{Label: "invalid", Url: "https://a.b.c"})
	assertNoError(t, dest, err)
	got, err := Lookup(dest)
	assertError(t, dest, err)
	assertLenOfResultsInRange(t, got, 0, 0)
}