fix grpc custom errors not being reported (#3230)

Author: rochdev

packages/datadog-instrumentations/src/grpc/server.js

@@ -107,7 +107,7 @@ function wrapStream (call, requestResource, onCancel) {
 function wrapCallback (callback, call, requestResource, parentResource, onCancel) {
   return function (err, value, trailer, flags) {
     requestResource.runInAsyncScope(() => {
-      if (err instanceof Error) {
+      if (err) {
         errorChannel.publish(err)
         finishChannel.publish(err)
       } else {

packages/datadog-plugin-grpc/test/server.spec.js

@@ -250,6 +250,27 @@ describe('Plugin', () => {
             })
         })
 
+        it('should handle custom errors', async () => {
+          const client = await buildClient({
+            getUnary: (_, callback) => {
+              const metadata = new grpc.Metadata()
+
+              metadata.set('extra', 'information')
+
+              callback({ message: 'foobar', code: grpc.status.NOT_FOUND }, {}, metadata)
+            }
+          })
+
+          client.getUnary({ first: 'foobar' }, () => {})
+
+          return agent
+            .use(traces => {
+              expect(traces[0][0]).to.have.property('error', 1)
+              expect(traces[0][0].meta).to.have.property(ERROR_MESSAGE, 'foobar')
+              expect(traces[0][0].metrics).to.have.property('grpc.status.code', 5)
+            })
+        })
+
         it('should handle stream errors', async () => {
           let error = null
 

packages/dd-trace/src/util.js

@@ -16,7 +16,7 @@ function isError (value) {
   if (value instanceof Error) {
     return true
   }
-  if (value && value.message && value.stack) {
+  if (value && value.message) {
     return true
   }
   return false