fix nil dereference (#10)

grpcurl.go

@@ -99,7 +99,7 @@ func resolveFileDescriptor(unresolved map[string]*descriptor.FileDescriptorProto
 	if !ok {
 		return nil, fmt.Errorf("no descriptor found for %q", filename)
 	}
-	deps := make([]*desc.FileDescriptor, len(fd.GetDependency()))
+	deps := make([]*desc.FileDescriptor, 0, len(fd.GetDependency()))
 	for _, dep := range fd.GetDependency() {
 		depFd, err := resolveFileDescriptor(unresolved, resolved, dep)
 		if err != nil {

grpcurl_test.go

@@ -116,6 +116,28 @@ func TestServerDoesNotSupportReflection(t *testing.T) {
 	}
 }
 
+func TestProtosetWithImports(t *testing.T) {
+	sourceProtoset, err := DescriptorSourceFromProtoSets("testing/example.protoset")
+	if err != nil {
+		t.Fatalf("failed to load protoset: %v", err)
+	}
+	// really shallow check of the loaded descriptors
+	if sd, err := sourceProtoset.FindSymbol("TestService"); err != nil {
+		t.Errorf("failed to find TestService in protoset: %v", err)
+	} else if sd == nil {
+		t.Errorf("FindSymbol returned nil for TestService")
+	} else if _, ok := sd.(*desc.ServiceDescriptor); !ok {
+		t.Errorf("FindSymbol returned wrong kind of descriptor for TestService: %T", sd)
+	}
+	if md, err := sourceProtoset.FindSymbol("TestRequest"); err != nil {
+		t.Errorf("failed to find TestRequest in protoset: %v", err)
+	} else if md == nil {
+		t.Errorf("FindSymbol returned nil for TestRequest")
+	} else if _, ok := md.(*desc.MessageDescriptor); !ok {
+		t.Errorf("FindSymbol returned wrong kind of descriptor for TestRequest: %T", md)
+	}
+}
+
 func TestListServicesProtoset(t *testing.T) {
 	doTestListServices(t, sourceProtoset, false)
 }

mk-test-files.sh

@@ -6,11 +6,14 @@ cd "$(dirname $0)"
 
 # Run this script to generate files used by tests.
 
-echo "Creating protoset..."
+echo "Creating protosets..."
 protoc ../../../google.golang.org/grpc/interop/grpc_testing/test.proto \
 	-I../../../ --include_imports \
 	--descriptor_set_out=testing/test.protoset
 
+protoc testing/example.proto \
+	--include_imports \
+	--descriptor_set_out=testing/example.protoset
 
 echo "Creating certs for TLS testing..."
 if ! hash certstrap 2>/dev/null; then

testing/example.proto

@@ -0,0 +1,19 @@
+syntax = "proto3";
+
+import "google/protobuf/descriptor.proto";
+import "google/protobuf/empty.proto";
+import "google/protobuf/timestamp.proto";
+
+message TestRequest {
+	repeated string file_names = 1;
+}
+
+message TestResponse {
+	map<string, google.protobuf.FileDescriptorProto> file_protos = 1;
+	google.protobuf.Timestamp last_update_date = 2;
+}
+
+service TestService {
+	rpc GetFiles (TestRequest) returns (TestResponse);
+	rpc Ping (google.protobuf.Empty) returns (google.protobuf.Empty);
+}