fix: clientMethodTrace missing original properties

Author: bgpo

experimental/packages/opentelemetry-instrumentation-grpc/src/grpc-js/index.ts

@@ -274,7 +274,7 @@ export class GrpcJsInstrumentation extends InstrumentationBase {
     const instrumentation = this;
     return (original: GrpcClientFunc) => {
       instrumentation._diag.debug('patch all client methods');
-      return function clientMethodTrace(this: grpcJs.Client) {
+      function clientMethodTrace(this: grpcJs.Client) {
         const name = `grpc.${original.path.replace('/', '')}`;
         const args = [...arguments];
         const metadata = getMetadata.call(
@@ -289,7 +289,9 @@ export class GrpcJsInstrumentation extends InstrumentationBase {
         return context.with(trace.setSpan(context.active(), span), () =>
           makeGrpcClientRemoteCall(original, args, metadata, this)(span)
         );
-      };
+      }
+      Object.assign(clientMethodTrace, original);
+      return clientMethodTrace;
     };
   }
 

experimental/packages/opentelemetry-instrumentation-grpc/src/grpc/index.ts

@@ -285,7 +285,7 @@ export class GrpcNativeInstrumentation extends InstrumentationBase<
     const instrumentation = this;
     return (original: GrpcClientFunc) => {
       instrumentation._diag.debug('patch all client methods');
-      return function clientMethodTrace(this: grpcTypes.Client) {
+      function clientMethodTrace(this: grpcTypes.Client) {
         const name = `grpc.${(original.path as string | undefined)?.replace(
           '/',
           ''
@@ -304,7 +304,9 @@ export class GrpcNativeInstrumentation extends InstrumentationBase<
             this
           )(span)
         );
-      };
+      }
+      Object.assign(clientMethodTrace, original);
+      return clientMethodTrace;
     };
   }
 }

experimental/packages/opentelemetry-instrumentation-grpc/test/helper.ts

@@ -646,6 +646,16 @@ export const runTests = (
       });
     };
 
+    const runClientMethodTest = (
+      method: typeof methodList[0]
+    ) => {
+      it(`should assign original properties for grpc remote method ${method.methodName}`, async () => {
+        const patchedClientMethod = (client as any)[method.methodName];
+        const properties = Object.keys(patchedClientMethod);
+        assert.ok(properties.length);
+      });
+    };
+
     describe('enable()', () => {
       const provider = new NodeTracerProvider();
       provider.addSpanProcessor(new SimpleSpanProcessor(memoryExporter));
@@ -801,5 +811,30 @@ export const runTests = (
         });
       });
     });
+
+    describe('Test assigning properties from original client method to patched client method', () => {
+      before(async () => {
+        plugin.disable();
+        plugin.setConfig({});
+        plugin.enable();
+
+        const packageDefinition = await protoLoader.load(PROTO_PATH, options);
+        const proto = grpc.loadPackageDefinition(packageDefinition).pkg_test;
+
+        client = createClient(grpc, proto);
+      });
+
+      after(done => {
+        client.close();
+        server.tryShutdown(() => {
+          plugin.disable();
+          done();
+        });
+      });
+
+      methodList.map(method => {
+        runClientMethodTest(method);
+      });
+    });
   });
 };