refactor(netxlite): improve tests for http and http3 (#487)

* refactor(netxlite): improve tests for http and http3

See https://github.com/ooni/probe/issues/1591

* Update internal/netxlite/http3.go

internal/netxlite/http3_test.go

@@ -1,42 +1,99 @@
 package netxlite
 
 import (
+	"context"
 	"crypto/tls"
+	"errors"
 	"net/http"
 	"testing"
 
-	"github.com/apex/log"
+	"github.com/lucas-clemente/quic-go"
+	"github.com/lucas-clemente/quic-go/http3"
 	"github.com/ooni/probe-cli/v3/internal/netxlite/mocks"
 )
 
-func TestHTTP3TransportWorks(t *testing.T) {
-	d := &quicDialerResolver{
-		Dialer: &quicDialerQUICGo{
-			QUICListener: &quicListenerStdlib{},
-		},
-		Resolver: NewResolverSystem(log.Log),
-	}
-	txp := NewHTTP3Transport(d, &tls.Config{})
-	client := &http.Client{Transport: txp}
-	resp, err := client.Get("https://www.google.com/robots.txt")
-	if err != nil {
-		t.Fatal(err)
-	}
-	resp.Body.Close()
-	txp.CloseIdleConnections()
+func TestHTTP3Dialer(t *testing.T) {
+	t.Run("Dial", func(t *testing.T) {
+		expected := errors.New("mocked error")
+		d := &http3Dialer{
+			QUICDialer: &mocks.QUICDialer{
+				MockDialContext: func(ctx context.Context, network, address string, tlsConfig *tls.Config, quicConfig *quic.Config) (quic.EarlySession, error) {
+					return nil, expected
+				},
+			},
+		}
+		sess, err := d.dial("", "", &tls.Config{}, &quic.Config{})
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected err", err)
+		}
+		if sess != nil {
+			t.Fatal("unexpected resp")
+		}
+	})
 }
 
 func TestHTTP3TransportClosesIdleConnections(t *testing.T) {
-	var called bool
-	d := &mocks.QUICDialer{
-		MockCloseIdleConnections: func() {
-			called = true
-		},
-	}
-	txp := NewHTTP3Transport(d, &tls.Config{})
-	client := &http.Client{Transport: txp}
-	client.CloseIdleConnections()
-	if !called {
-		t.Fatal("not called")
-	}
+	t.Run("CloseIdleConnections", func(t *testing.T) {
+		var (
+			calledHTTP3  bool
+			calledDialer bool
+		)
+		txp := &http3Transport{
+			child: &mocks.HTTP3RoundTripper{
+				MockClose: func() error {
+					calledHTTP3 = true
+					return nil
+				},
+			},
+			dialer: &mocks.QUICDialer{
+				MockCloseIdleConnections: func() {
+					calledDialer = true
+				},
+			},
+		}
+		txp.CloseIdleConnections()
+		if !calledHTTP3 || !calledDialer {
+			t.Fatal("not called")
+		}
+	})
+
+	t.Run("RoundTrip", func(t *testing.T) {
+		expected := errors.New("mocked error")
+		txp := &http3Transport{
+			child: &mocks.HTTP3RoundTripper{
+				MockRoundTrip: func(req *http.Request) (*http.Response, error) {
+					return nil, expected
+				},
+			},
+		}
+		resp, err := txp.RoundTrip(&http.Request{})
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected err", err)
+		}
+		if resp != nil {
+			t.Fatal("unexpected resp")
+		}
+	})
+}
+
+func TestNewHTTP3Transport(t *testing.T) {
+	t.Run("creates the correct type chain", func(t *testing.T) {
+		qd := &mocks.QUICDialer{}
+		config := &tls.Config{}
+		txp := NewHTTP3Transport(qd, config)
+		h3txp := txp.(*http3Transport)
+		if h3txp.dialer != qd {
+			t.Fatal("invalid dialer")
+		}
+		h3 := h3txp.child.(*http3.RoundTripper)
+		if h3.Dial == nil {
+			t.Fatal("invalid Dial")
+		}
+		if !h3.DisableCompression {
+			t.Fatal("invalid DisableCompression")
+		}
+		if h3.TLSClientConfig != config {
+			t.Fatal("invalid TLSClientConfig")
+		}
+	})
 }