encoding: move codec tests out of top-level test package (#6728)

Author: easwars

encoding/encoding_test.go

@@ -16,35 +16,63 @@
  *
  */
 
-package encoding
+package encoding_test
 
 import (
+	"context"
+	"errors"
+	"fmt"
+	"strings"
+	"sync/atomic"
 	"testing"
+	"time"
 
 	"github.com/google/go-cmp/cmp"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/encoding"
+	"google.golang.org/grpc/encoding/proto"
+	"google.golang.org/grpc/internal/grpctest"
 	"google.golang.org/grpc/internal/grpcutil"
+	"google.golang.org/grpc/internal/stubserver"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
+
+	testgrpc "google.golang.org/grpc/interop/grpc_testing"
+	testpb "google.golang.org/grpc/interop/grpc_testing"
 )
 
+const defaultTestTimeout = 10 * time.Second
+
+type s struct {
+	grpctest.Tester
+}
+
+func Test(t *testing.T) {
+	grpctest.RunSubTests(t, s{})
+}
+
 type mockNamedCompressor struct {
-	Compressor
+	encoding.Compressor
 }
 
 func (mockNamedCompressor) Name() string {
 	return "mock-compressor"
 }
 
-func TestDuplicateCompressorRegister(t *testing.T) {
-	defer func(m map[string]Compressor) { registeredCompressor = m }(registeredCompressor)
-	defer func(c []string) { grpcutil.RegisteredCompressorNames = c }(grpcutil.RegisteredCompressorNames)
-	registeredCompressor = map[string]Compressor{}
-	grpcutil.RegisteredCompressorNames = []string{}
-
-	RegisterCompressor(&mockNamedCompressor{})
+// Tests the case where a compressor with the same name is registered multiple
+// times. Test verifies the following:
+//   - the most recent registration is the one which is active
+//   - grpcutil.RegisteredCompressorNames contains a single instance of the
+//     previously registered compressor's name
+func (s) TestDuplicateCompressorRegister(t *testing.T) {
+	encoding.RegisterCompressor(&mockNamedCompressor{})
 
 	// Register another instance of the same compressor.
 	mc := &mockNamedCompressor{}
-	RegisterCompressor(mc)
-	if got := registeredCompressor["mock-compressor"]; got != mc {
+	encoding.RegisterCompressor(mc)
+	if got := encoding.GetCompressor("mock-compressor"); got != mc {
 		t.Fatalf("Unexpected compressor, got: %+v, want:%+v", got, mc)
 	}
 
@@ -53,3 +81,284 @@ func TestDuplicateCompressorRegister(t *testing.T) {
 		t.Fatalf("Unexpected compressor names, got: %+v, want:%+v", grpcutil.RegisteredCompressorNames, wantNames)
 	}
 }
+
+// errProtoCodec wraps the proto codec and delegates to it if it is configured
+// to return a nil error. Else, it returns the configured error.
+type errProtoCodec struct {
+	name        string
+	encodingErr error
+	decodingErr error
+}
+
+func (c *errProtoCodec) Marshal(v any) ([]byte, error) {
+	if c.encodingErr != nil {
+		return nil, c.encodingErr
+	}
+	return encoding.GetCodec(proto.Name).Marshal(v)
+}
+
+func (c *errProtoCodec) Unmarshal(data []byte, v any) error {
+	if c.decodingErr != nil {
+		return c.decodingErr
+	}
+	return encoding.GetCodec(proto.Name).Unmarshal(data, v)
+}
+
+func (c *errProtoCodec) Name() string {
+	return c.name
+}
+
+// Tests the case where encoding fails on the server. Verifies that there is
+// no panic and that the encoding error is propagated to the client.
+func (s) TestEncodeDoesntPanicOnServer(t *testing.T) {
+	grpctest.TLogger.ExpectError("grpc: server failed to encode response")
+
+	// Create an codec that errors when encoding messages.
+	encodingErr := errors.New("encoding failed")
+	ec := &errProtoCodec{name: t.Name(), encodingErr: encodingErr}
+
+	// Start a server with the above codec.
+	backend := stubserver.StartTestService(t, nil, grpc.ForceServerCodec(ec))
+	defer backend.Stop()
+
+	// Create a channel to the above server.
+	cc, err := grpc.Dial(backend.Address, grpc.WithTransportCredentials(insecure.NewCredentials()))
+	if err != nil {
+		t.Fatalf("Failed to dial test backend at %q: %v", backend.Address, err)
+	}
+	defer cc.Close()
+
+	// Make an RPC and expect it to fail. Since we do not specify any codec
+	// here, the proto codec will get automatically used.
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+	client := testgrpc.NewTestServiceClient(cc)
+	_, err = client.EmptyCall(ctx, &testpb.Empty{})
+	if err == nil || !strings.Contains(err.Error(), encodingErr.Error()) {
+		t.Fatalf("RPC failed with error: %v, want: %v", err, encodingErr)
+	}
+
+	// Configure the codec on the server to not return errors anymore and expect
+	// the RPC to succeed.
+	ec.encodingErr = nil
+	if _, err := client.EmptyCall(ctx, &testpb.Empty{}); err != nil {
+		t.Fatalf("RPC failed with error: %v", err)
+	}
+}
+
+// Tests the case where decoding fails on the server. Verifies that there is
+// no panic and that the decoding error is propagated to the client.
+func (s) TestDecodeDoesntPanicOnServer(t *testing.T) {
+	// Create an codec that errors when decoding messages.
+	decodingErr := errors.New("decoding failed")
+	ec := &errProtoCodec{name: t.Name(), decodingErr: decodingErr}
+
+	// Start a server with the above codec.
+	backend := stubserver.StartTestService(t, nil, grpc.ForceServerCodec(ec))
+	defer backend.Stop()
+
+	// Create a channel to the above server. Since we do not specify any codec
+	// here, the proto codec will get automatically used.
+	cc, err := grpc.Dial(backend.Address, grpc.WithTransportCredentials(insecure.NewCredentials()))
+	if err != nil {
+		t.Fatalf("Failed to dial test backend at %q: %v", backend.Address, err)
+	}
+	defer cc.Close()
+
+	// Make an RPC and expect it to fail. Since we do not specify any codec
+	// here, the proto codec will get automatically used.
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+	client := testgrpc.NewTestServiceClient(cc)
+	_, err = client.EmptyCall(ctx, &testpb.Empty{})
+	if err == nil || !strings.Contains(err.Error(), decodingErr.Error()) || !strings.Contains(err.Error(), "grpc: error unmarshalling request") {
+		t.Fatalf("RPC failed with error: %v, want: %v", err, decodingErr)
+	}
+
+	// Configure the codec on the server to not return errors anymore and expect
+	// the RPC to succeed.
+	ec.decodingErr = nil
+	if _, err := client.EmptyCall(ctx, &testpb.Empty{}); err != nil {
+		t.Fatalf("RPC failed with error: %v", err)
+	}
+}
+
+// Tests the case where encoding fails on the client . Verifies that there is
+// no panic and that the encoding error is propagated to the RPC caller.
+func (s) TestEncodeDoesntPanicOnClient(t *testing.T) {
+	// Start a server and since we do not specify any codec here, the proto
+	// codec will get automatically used.
+	backend := stubserver.StartTestService(t, nil)
+	defer backend.Stop()
+
+	// Create an codec that errors when encoding messages.
+	encodingErr := errors.New("encoding failed")
+	ec := &errProtoCodec{name: t.Name(), encodingErr: encodingErr}
+
+	// Create a channel to the above server.
+	cc, err := grpc.Dial(backend.Address, grpc.WithTransportCredentials(insecure.NewCredentials()))
+	if err != nil {
+		t.Fatalf("Failed to dial test backend at %q: %v", backend.Address, err)
+	}
+	defer cc.Close()
+
+	// Make an RPC with the erroring codec and expect it to fail.
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+	client := testgrpc.NewTestServiceClient(cc)
+	_, err = client.EmptyCall(ctx, &testpb.Empty{}, grpc.ForceCodec(ec))
+	if err == nil || !strings.Contains(err.Error(), encodingErr.Error()) {
+		t.Fatalf("RPC failed with error: %v, want: %v", err, encodingErr)
+	}
+
+	// Configure the codec on the client to not return errors anymore and expect
+	// the RPC to succeed.
+	ec.encodingErr = nil
+	if _, err := client.EmptyCall(ctx, &testpb.Empty{}, grpc.ForceCodec(ec)); err != nil {
+		t.Fatalf("RPC failed with error: %v", err)
+	}
+}
+
+// Tests the case where decoding fails on the server. Verifies that there is
+// no panic and that the decoding error is propagated to the RPC caller.
+func (s) TestDecodeDoesntPanicOnClient(t *testing.T) {
+	// Start a server and since we do not specify any codec here, the proto
+	// codec will get automatically used.
+	backend := stubserver.StartTestService(t, nil)
+	defer backend.Stop()
+
+	// Create an codec that errors when decoding messages.
+	decodingErr := errors.New("decoding failed")
+	ec := &errProtoCodec{name: t.Name(), decodingErr: decodingErr}
+
+	// Create a channel to the above server.
+	cc, err := grpc.Dial(backend.Address, grpc.WithTransportCredentials(insecure.NewCredentials()))
+	if err != nil {
+		t.Fatalf("Failed to dial test backend at %q: %v", backend.Address, err)
+	}
+	defer cc.Close()
+
+	// Make an RPC with the erroring codec and expect it to fail.
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+	client := testgrpc.NewTestServiceClient(cc)
+	_, err = client.EmptyCall(ctx, &testpb.Empty{}, grpc.ForceCodec(ec))
+	if err == nil || !strings.Contains(err.Error(), decodingErr.Error()) {
+		t.Fatalf("RPC failed with error: %v, want: %v", err, decodingErr)
+	}
+
+	// Configure the codec on the client to not return errors anymore and expect
+	// the RPC to succeed.
+	ec.decodingErr = nil
+	if _, err := client.EmptyCall(ctx, &testpb.Empty{}, grpc.ForceCodec(ec)); err != nil {
+		t.Fatalf("RPC failed with error: %v", err)
+	}
+}
+
+// countingProtoCodec wraps the proto codec and counts the number of times
+// Marshal and Unmarshal are called.
+type countingProtoCodec struct {
+	name string
+
+	// The following fields are accessed atomically.
+	marshalCount   int32
+	unmarshalCount int32
+}
+
+func (p *countingProtoCodec) Marshal(v any) ([]byte, error) {
+	atomic.AddInt32(&p.marshalCount, 1)
+	return encoding.GetCodec(proto.Name).Marshal(v)
+}
+
+func (p *countingProtoCodec) Unmarshal(data []byte, v any) error {
+	atomic.AddInt32(&p.unmarshalCount, 1)
+	return encoding.GetCodec(proto.Name).Unmarshal(data, v)
+}
+
+func (p *countingProtoCodec) Name() string {
+	return p.name
+}
+
+// Tests the case where ForceServerCodec option is used on the server. Verifies
+// that encoding and decoding happen once per RPC.
+func (s) TestForceServerCodec(t *testing.T) {
+	// Create an server with the counting proto codec.
+	codec := &countingProtoCodec{name: t.Name()}
+	backend := stubserver.StartTestService(t, nil, grpc.ForceServerCodec(codec))
+	defer backend.Stop()
+
+	// Create a channel to the above server.
+	cc, err := grpc.Dial(backend.Address, grpc.WithTransportCredentials(insecure.NewCredentials()))
+	if err != nil {
+		t.Fatalf("Failed to dial test backend at %q: %v", backend.Address, err)
+	}
+	defer cc.Close()
+
+	// Make an RPC and expect it to fail. Since we do not specify any codec
+	// here, the proto codec will get automatically used.
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+	client := testgrpc.NewTestServiceClient(cc)
+	if _, err := client.EmptyCall(ctx, &testpb.Empty{}); err != nil {
+		t.Fatalf("ss.Client.EmptyCall(_, _) = _, %v; want _, nil", err)
+	}
+
+	unmarshalCount := atomic.LoadInt32(&codec.unmarshalCount)
+	const wantUnmarshalCount = 1
+	if unmarshalCount != wantUnmarshalCount {
+		t.Fatalf("Unmarshal Count = %d; want %d", unmarshalCount, wantUnmarshalCount)
+	}
+	marshalCount := atomic.LoadInt32(&codec.marshalCount)
+	const wantMarshalCount = 1
+	if marshalCount != wantMarshalCount {
+		t.Fatalf("MarshalCount = %d; want %d", marshalCount, wantMarshalCount)
+	}
+}
+
+// renameProtoCodec wraps the proto codec and allows customizing the Name().
+type renameProtoCodec struct {
+	encoding.Codec
+	name string
+}
+
+func (r *renameProtoCodec) Name() string { return r.name }
+
+// TestForceCodecName confirms that the ForceCodec call option sets the subtype
+// in the content-type header according to the Name() of the codec provided.
+// Verifies that the name is converted to lowercase before transmitting.
+func (s) TestForceCodecName(t *testing.T) {
+	wantContentTypeCh := make(chan []string, 1)
+	defer close(wantContentTypeCh)
+
+	// Create a test service backend that pushes the received content-type on a
+	// channel for the test to inspect.
+	ss := &stubserver.StubServer{
+		EmptyCallF: func(ctx context.Context, in *testpb.Empty) (*testpb.Empty, error) {
+			md, ok := metadata.FromIncomingContext(ctx)
+			if !ok {
+				return nil, status.Errorf(codes.Internal, "no metadata in context")
+			}
+			if got, want := md["content-type"], <-wantContentTypeCh; !cmp.Equal(got, want) {
+				return nil, status.Errorf(codes.Internal, "got content-type=%q; want [%q]", got, want)
+			}
+			return &testpb.Empty{}, nil
+		},
+	}
+	// Since we don't specify a codec as a server option, it will end up
+	// automatically using the proto codec.
+	if err := ss.Start(nil); err != nil {
+		t.Fatalf("Error starting endpoint server: %v", err)
+	}
+	defer ss.Stop()
+
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+
+	// Force the use of the custom codec on the client with the ForceCodec call
+	// option. Confirm the name is converted to lowercase before transmitting.
+	codec := &renameProtoCodec{Codec: encoding.GetCodec(proto.Name), name: t.Name()}
+	wantContentTypeCh <- []string{fmt.Sprintf("application/grpc+%s", strings.ToLower(t.Name()))}
+	if _, err := ss.Client.EmptyCall(ctx, &testpb.Empty{}, grpc.ForceCodec(codec)); err != nil {
+		t.Fatalf("ss.Client.EmptyCall(_, _) = _, %v; want _, nil", err)
+	}
+}