refactor: move ErrorWrapperQUICDialer to errorsx (#420)

I needed to add some tests as integration tests due to circular
imports, but this is ~fine because we quite likely want many
integration tests in the errorsx package anyway.

Part of https://github.com/ooni/probe/issues/1505.

internal/engine/netx/netx.go

@@ -171,7 +171,7 @@ func NewQUICDialer(config Config) QUICDialer {
 	var d quicdialer.ContextDialer = &netxlite.QUICDialerQUICGo{
 		QUICListener: ql,
 	}
-	d = quicdialer.ErrorWrapperDialer{Dialer: d}
+	d = &errorsx.ErrorWrapperQUICDialer{Dialer: d}
 	if config.TLSSaver != nil {
 		d = quicdialer.HandshakeSaver{Saver: config.TLSSaver, Dialer: d}
 	}

internal/engine/netx/quicdialer/errorwrapper.go

@@ -1,30 +0,0 @@
-package quicdialer
-
-import (
-	"context"
-	"crypto/tls"
-
-	"github.com/lucas-clemente/quic-go"
-	"github.com/ooni/probe-cli/v3/internal/errorsx"
-)
-
-// ErrorWrapperDialer is a dialer that performs quic err wrapping
-type ErrorWrapperDialer struct {
-	Dialer ContextDialer
-}
-
-// DialContext implements ContextDialer.DialContext
-func (d ErrorWrapperDialer) DialContext(
-	ctx context.Context, network string, host string,
-	tlsCfg *tls.Config, cfg *quic.Config) (quic.EarlySession, error) {
-	sess, err := d.Dialer.DialContext(ctx, network, host, tlsCfg, cfg)
-	err = errorsx.SafeErrWrapperBuilder{
-		Classifier: errorsx.ClassifyQUICFailure,
-		Error:      err,
-		Operation:  errorsx.QUICHandshakeOperation,
-	}.MaybeBuild()
-	if err != nil {
-		return nil, err
-	}
-	return sess, nil
-}

internal/engine/netx/quicdialer/errorwrapper_test.go

@@ -1,85 +0,0 @@
-package quicdialer_test
-
-import (
-	"context"
-	"crypto/tls"
-	"errors"
-	"io"
-	"testing"
-
-	"github.com/lucas-clemente/quic-go"
-	"github.com/ooni/probe-cli/v3/internal/engine/netx/quicdialer"
-	"github.com/ooni/probe-cli/v3/internal/errorsx"
-	"github.com/ooni/probe-cli/v3/internal/netxlite"
-)
-
-func TestErrorWrapperFailure(t *testing.T) {
-	ctx := context.Background()
-	d := quicdialer.ErrorWrapperDialer{
-		Dialer: MockDialer{Sess: nil, Err: io.EOF}}
-	sess, err := d.DialContext(
-		ctx, "udp", "www.google.com:443", &tls.Config{}, &quic.Config{})
-	if sess != nil {
-		t.Fatal("expected a nil sess here")
-	}
-	errorWrapperCheckErr(t, err, errorsx.QUICHandshakeOperation)
-}
-
-func errorWrapperCheckErr(t *testing.T, err error, op string) {
-	if !errors.Is(err, io.EOF) {
-		t.Fatal("expected another error here")
-	}
-	var errWrapper *errorsx.ErrWrapper
-	if !errors.As(err, &errWrapper) {
-		t.Fatal("cannot cast to ErrWrapper")
-	}
-	if errWrapper.Operation != op {
-		t.Fatal("unexpected Operation")
-	}
-	if errWrapper.Failure != errorsx.FailureEOFError {
-		t.Fatal("unexpected failure")
-	}
-}
-
-func TestErrorWrapperInvalidCertificate(t *testing.T) {
-	nextprotos := []string{"h3"}
-	servername := "example.com"
-	tlsConf := &tls.Config{
-		NextProtos: nextprotos,
-		ServerName: servername,
-	}
-
-	dlr := quicdialer.ErrorWrapperDialer{Dialer: &netxlite.QUICDialerQUICGo{
-		QUICListener: &netxlite.QUICListenerStdlib{},
-	}}
-	// use Google IP
-	sess, err := dlr.DialContext(context.Background(), "udp",
-		"216.58.212.164:443", tlsConf, &quic.Config{})
-	if err == nil {
-		t.Fatal("expected an error here")
-	}
-	if sess != nil {
-		t.Fatal("expected nil sess here")
-	}
-	if err.Error() != errorsx.FailureSSLInvalidCertificate {
-		t.Fatal("unexpected failure")
-	}
-}
-
-func TestErrorWrapperSuccess(t *testing.T) {
-	ctx := context.Background()
-	tlsConf := &tls.Config{
-		NextProtos: []string{"h3"},
-		ServerName: "www.google.com",
-	}
-	d := quicdialer.ErrorWrapperDialer{Dialer: &netxlite.QUICDialerQUICGo{
-		QUICListener: &netxlite.QUICListenerStdlib{},
-	}}
-	sess, err := d.DialContext(ctx, "udp", "216.58.212.164:443", tlsConf, &quic.Config{})
-	if err != nil {
-		t.Fatal(err)
-	}
-	if sess == nil {
-		t.Fatal("expected non-nil sess here")
-	}
-}

internal/errorsx/integration_test.go

@@ -0,0 +1,54 @@
+package errorsx_test
+
+import (
+	"context"
+	"crypto/tls"
+	"testing"
+
+	"github.com/lucas-clemente/quic-go"
+	"github.com/ooni/probe-cli/v3/internal/errorsx"
+	"github.com/ooni/probe-cli/v3/internal/netxlite"
+)
+
+func TestErrorWrapperQUICDialerInvalidCertificate(t *testing.T) {
+	nextprotos := []string{"h3"}
+	servername := "example.com"
+	tlsConf := &tls.Config{
+		NextProtos: nextprotos,
+		ServerName: servername,
+	}
+
+	dlr := &errorsx.ErrorWrapperQUICDialer{Dialer: &netxlite.QUICDialerQUICGo{
+		QUICListener: &netxlite.QUICListenerStdlib{},
+	}}
+	// use Google IP
+	sess, err := dlr.DialContext(context.Background(), "udp",
+		"216.58.212.164:443", tlsConf, &quic.Config{})
+	if err == nil {
+		t.Fatal("expected an error here")
+	}
+	if sess != nil {
+		t.Fatal("expected nil sess here")
+	}
+	if err.Error() != errorsx.FailureSSLInvalidCertificate {
+		t.Fatal("unexpected failure")
+	}
+}
+
+func TestErrorWrapperQUICDialerSuccess(t *testing.T) {
+	ctx := context.Background()
+	tlsConf := &tls.Config{
+		NextProtos: []string{"h3"},
+		ServerName: "www.google.com",
+	}
+	d := &errorsx.ErrorWrapperQUICDialer{Dialer: &netxlite.QUICDialerQUICGo{
+		QUICListener: &netxlite.QUICListenerStdlib{},
+	}}
+	sess, err := d.DialContext(ctx, "udp", "216.58.212.164:443", tlsConf, &quic.Config{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if sess == nil {
+		t.Fatal("expected non-nil sess here")
+	}
+}

internal/errorsx/quic.go

@@ -0,0 +1,38 @@
+package errorsx
+
+import (
+	"context"
+	"crypto/tls"
+
+	"github.com/lucas-clemente/quic-go"
+)
+
+// QUICContextDialer is a dialer for QUIC using Context.
+type QUICContextDialer interface {
+	// DialContext establishes a new QUIC session using the given
+	// network and address. The tlsConfig and the quicConfig arguments
+	// MUST NOT be nil. Returns either the session or an error.
+	DialContext(ctx context.Context, network, address string,
+		tlsConfig *tls.Config, quicConfig *quic.Config) (quic.EarlySession, error)
+}
+
+// ErrorWrapperQUICDialer is a dialer that performs quic err wrapping
+type ErrorWrapperQUICDialer struct {
+	Dialer QUICContextDialer
+}
+
+// DialContext implements ContextDialer.DialContext
+func (d *ErrorWrapperQUICDialer) DialContext(
+	ctx context.Context, network string, host string,
+	tlsCfg *tls.Config, cfg *quic.Config) (quic.EarlySession, error) {
+	sess, err := d.Dialer.DialContext(ctx, network, host, tlsCfg, cfg)
+	err = SafeErrWrapperBuilder{
+		Classifier: ClassifyQUICFailure,
+		Error:      err,
+		Operation:  QUICHandshakeOperation,
+	}.MaybeBuild()
+	if err != nil {
+		return nil, err
+	}
+	return sess, nil
+}

internal/errorsx/quic_test.go

@@ -0,0 +1,39 @@
+package errorsx
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"io"
+	"testing"
+
+	"github.com/lucas-clemente/quic-go"
+	"github.com/ooni/probe-cli/v3/internal/netxmocks"
+)
+
+func TestErrorWrapperQUICDialerFailure(t *testing.T) {
+	ctx := context.Background()
+	d := &ErrorWrapperQUICDialer{Dialer: &netxmocks.QUICContextDialer{
+		MockDialContext: func(ctx context.Context, network, address string, tlsConfig *tls.Config, quicConfig *quic.Config) (quic.EarlySession, error) {
+			return nil, io.EOF
+		},
+	}}
+	sess, err := d.DialContext(
+		ctx, "udp", "www.google.com:443", &tls.Config{}, &quic.Config{})
+	if sess != nil {
+		t.Fatal("expected a nil sess here")
+	}
+	if !errors.Is(err, io.EOF) {
+		t.Fatal("expected another error here")
+	}
+	var errWrapper *ErrWrapper
+	if !errors.As(err, &errWrapper) {
+		t.Fatal("cannot cast to ErrWrapper")
+	}
+	if errWrapper.Operation != QUICHandshakeOperation {
+		t.Fatal("unexpected Operation")
+	}
+	if errWrapper.Failure != FailureEOFError {
+		t.Fatal("unexpected failure")
+	}
+}