add tests

internal/experiment/openvpn/targets.go

@@ -15,31 +15,31 @@ const defaultOpenVPNEndpoint = "openvpn-server1.ooni.io"
 // and perhaps also transform DNS failure into a specific failure of the experiment, not
 // a skip.
 // TODO(ain): update the openvpn spec to reflect the CURRENT state of delivering the targets.
-func resolveTarget() (string, error) {
-	ips, err := net.LookupIP(defaultOpenVPNEndpoint)
+func resolveTarget(domain string) (string, error) {
+	ips, err := net.LookupIP(domain)
 	if err != nil {
 		return "", err
 	}
-	if len(ips) == 0 {
-		return "", fmt.Errorf("cannot resolve %v", defaultOpenVPNEndpoint)
+	if len(ips) > 0 {
+		return ips[0].String(), nil
 	}
-	return ips[0].String(), nil
+	return "", fmt.Errorf("cannot resolve %v", defaultOpenVPNEndpoint)
 }
 
 func defaultOONITargetURL(ip string) string {
 	return "openvpn://oonivpn.corp/?address=" + ip + ":1194"
 }
 
 func defaultOONIOpenVPNTargetUDP() (string, error) {
-	ip, err := resolveTarget()
+	ip, err := resolveTarget(defaultOpenVPNEndpoint)
 	if err != nil {
 		return "", err
 	}
 	return defaultOONITargetURL(ip) + "&transport=udp", nil
 }
 
 func defaultOONIOpenVPNTargetTCP() (string, error) {
-	ip, err := resolveTarget()
+	ip, err := resolveTarget(defaultOpenVPNEndpoint)
 	if err != nil {
 		return "", err
 	}

internal/experiment/openvpn/targets_test.go

@@ -0,0 +1,57 @@
+package openvpn
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func Test_resolveTarget(t *testing.T) {
+	_, err := resolveTarget("google.com")
+	if err != nil {
+		t.Fatal("should be able to resolve the target")
+	}
+
+	_, err = resolveTarget("nothing.corp")
+	if err == nil {
+		t.Fatal("should be able to resolve the target")
+	}
+
+	_, err = resolveTarget("asfasfasfasfasfafs.ooni.io")
+	if err == nil {
+		t.Fatal("should be able to resolve the target")
+	}
+}
+
+func Test_defaultOONIOpenVPNTargetUDP(t *testing.T) {
+	url, err := defaultOONIOpenVPNTargetUDP()
+	if err != nil {
+		t.Fatal("unexpected error")
+	}
+	expected := "openvpn://oonivpn.corp/?address=37.218.243.98:1194&transport=udp"
+	if diff := cmp.Diff(url, expected); diff != "" {
+		t.Fatal(diff)
+	}
+}
+
+func Test_defaultOONIOpenVPNTargetTCP(t *testing.T) {
+	url, err := defaultOONIOpenVPNTargetTCP()
+	if err != nil {
+		t.Fatal("unexpected error")
+	}
+	expected := "openvpn://oonivpn.corp/?address=37.218.243.98:1194&transport=tcp"
+	if diff := cmp.Diff(url, expected); diff != "" {
+		t.Fatal(diff)
+	}
+}
+
+func Test_pickFromDefaultOONIOpenVPNConfig(t *testing.T) {
+	pick := pickFromDefaultOONIOpenVPNConfig()
+
+	if pick.Cipher != "AES-256-GCM" {
+		t.Fatal("cipher unexpected")
+	}
+	if pick.SafeCA != defaultCA {
+		t.Fatal("ca unexpected")
+	}
+}