Add omit_request_instanceof generator option

Author: lionello

packages/grpc-tools/README.md

@@ -20,3 +20,7 @@ one of the following:
    gRPC library, and instead generates `PackageDefinition` objects that can
    be passed to the `loadPackageDefinition` function provided by both the
    `grpc` and `@grpc/grpc-js` libraries.
+ - `omit_request_instanceof`: Omit the `instanceof` check for request messages
+   in client code. This is useful when the request message was renamed or is
+   from a different package, and request serialization would fail with
+   `Expected argument of type …`.

packages/grpc-tools/src/node_generator.cc

@@ -120,7 +120,9 @@ grpc::string NodeObjectPath(const Descriptor* descriptor) {
 }
 
 // Prints out the message serializer and deserializer functions
-void PrintMessageTransformer(const Descriptor* descriptor, Printer* out) {
+void PrintMessageTransformer(const Descriptor* descriptor,
+                             Printer* out,
+                             const Parameters& params) {
   map<grpc::string, grpc::string> template_vars;
   grpc::string full_name = descriptor->full_name();
   template_vars["identifier_name"] = MessageIdentifierName(full_name);
@@ -129,12 +131,14 @@ void PrintMessageTransformer(const Descriptor* descriptor, Printer* out) {
   // Print the serializer
   out->Print(template_vars, "function serialize_$identifier_name$(arg) {\n");
   out->Indent();
-  out->Print(template_vars, "if (!(arg instanceof $node_name$)) {\n");
-  out->Indent();
-  out->Print(template_vars,
-             "throw new Error('Expected argument of type $name$');\n");
-  out->Outdent();
-  out->Print("}\n");
+  if (!params.omit_request_instanceof) {
+    out->Print(template_vars, "if (!(arg instanceof $node_name$)) {\n");
+    out->Indent();
+    out->Print(template_vars,
+              "throw new Error('Expected argument of type $name$');\n");
+    out->Outdent();
+    out->Print("}\n");
+  }
   out->Print("return Buffer.from(arg.serializeBinary());\n");
   out->Outdent();
   out->Print("}\n\n");
@@ -232,12 +236,14 @@ void PrintImports(const FileDescriptor* file, Printer* out,
   out->Print("\n");
 }
 
-void PrintTransformers(const FileDescriptor* file, Printer* out) {
+void PrintTransformers(const FileDescriptor* file,
+                       Printer* out,
+                       const Parameters& params) {
   map<grpc::string, const Descriptor*> messages = GetAllMessages(file);
   for (std::map<grpc::string, const Descriptor*>::iterator it =
            messages.begin();
        it != messages.end(); it++) {
-    PrintMessageTransformer(it->second, out);
+    PrintMessageTransformer(it->second, out, params);
   }
   out->Print("\n");
 }
@@ -273,7 +279,7 @@ grpc::string GenerateFile(const FileDescriptor* file,
 
     PrintImports(file, &out, params);
 
-    PrintTransformers(file, &out);
+    PrintTransformers(file, &out, params);
 
     PrintServices(file, &out, params);
 

packages/grpc-tools/src/node_generator.h

@@ -28,6 +28,8 @@ struct Parameters {
   bool generate_package_definition;
   // Use pure JavaScript gRPC Client
   bool grpc_js;
+  // Omit instanceof check for request messages
+  bool omit_request_instanceof;
 };
 
 grpc::string GenerateFile(const grpc::protobuf::FileDescriptor* file,

packages/grpc-tools/src/node_plugin.cc

@@ -39,6 +39,7 @@ class NodeGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
     grpc_node_generator::Parameters generator_parameters;
     generator_parameters.generate_package_definition = false;
     generator_parameters.grpc_js = false;
+    generator_parameters.omit_request_instanceof = false;
     if (!parameter.empty()) {
       std::vector<grpc::string> parameters_list =
           grpc_generator::tokenize(parameter, ",");
@@ -48,6 +49,8 @@ class NodeGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
           generator_parameters.generate_package_definition = true;
         } else if (*parameter_string == "grpc_js") {
           generator_parameters.grpc_js = true;
+        } else if (*parameter_string == "omit_request_instanceof") {
+          generator_parameters.omit_request_instanceof = true;
         }
       }
     }