GODRIVER-1706 Ensure codeName is propagated for errors (#458)

Author: Divjot Arora

mongo/errors.go

@@ -201,7 +201,12 @@ func convertDriverWriteConcernError(wce *driver.WriteConcernError) *WriteConcern
 		return nil
 	}
 
-	return &WriteConcernError{Code: int(wce.Code), Message: wce.Message, Details: bson.Raw(wce.Details)}
+	return &WriteConcernError{
+		Name:    wce.Name,
+		Code:    int(wce.Code),
+		Message: wce.Message,
+		Details: bson.Raw(wce.Details),
+	}
 }
 
 // BulkWriteError is an error that occurred during execution of one operation in a BulkWrite. This error type is only

mongo/integration/collection_test.go

@@ -32,14 +32,16 @@ const (
 	errorModifiedID             = 66
 )
 
-func TestCollection(t *testing.T) {
-	mt := mtest.New(t, mtest.NewOptions().CreateClient(false))
-	defer mt.Close()
-
+var (
 	// impossibleWc is a write concern that can't be satisfied and is used to test write concern errors
 	// for various operations. It includes a timeout because legacy servers will wait for all W nodes to respond,
 	// causing tests to hang.
-	impossibleWc := writeconcern.New(writeconcern.W(30), writeconcern.WTimeout(time.Second))
+	impossibleWc = writeconcern.New(writeconcern.W(30), writeconcern.WTimeout(time.Second))
+)
+
+func TestCollection(t *testing.T) {
+	mt := mtest.New(t, mtest.NewOptions().CreateClient(false))
+	defer mt.Close()
 
 	mt.RunOpts("insert one", noClientOpts, func(mt *mtest.T) {
 		mt.Run("success", func(mt *mtest.T) {

mongo/integration/crud_prose_test.go

@@ -65,3 +65,52 @@ func TestAggregateSecondaryPreferredReadPreference(t *testing.T) {
 		assert.NotNil(mt, err, "expected command %s to not contain $readPreference", evt.Command)
 	})
 }
+
+func TestErrorsCodeNamePropagated(t *testing.T) {
+	// Ensure the codeName field is propagated for both command and write concern errors.
+
+	mtOpts := mtest.NewOptions().
+		Topologies(mtest.ReplicaSet).
+		CreateClient(false)
+	mt := mtest.New(t, mtOpts)
+	defer mt.Close()
+
+	mt.RunOpts("command error", mtest.NewOptions().MinServerVersion("3.4"), func(mt *mtest.T) {
+		// codeName is propagated in an ok:0 error.
+
+		cmd := bson.D{
+			{"insert", mt.Coll.Name()},
+			{"documents", []bson.D{}},
+		}
+		err := mt.DB.RunCommand(mtest.Background, cmd).Err()
+		assert.NotNil(mt, err, "expected RunCommand error, got nil")
+
+		ce, ok := err.(mongo.CommandError)
+		assert.True(mt, ok, "expected error of type %T, got %v of type %T", mongo.CommandError{}, err, err)
+		expectedCodeName := "InvalidLength"
+		assert.Equal(mt, expectedCodeName, ce.Name, "expected error code name %q, got %q", expectedCodeName, ce.Name)
+	})
+
+	wcCollOpts := options.Collection().
+		SetWriteConcern(impossibleWc)
+	wcMtOpts := mtest.NewOptions().
+		CollectionOptions(wcCollOpts)
+	mt.RunOpts("write concern error", wcMtOpts, func(mt *mtest.T) {
+		// codeName is propagated for write concern errors.
+
+		_, err := mt.Coll.InsertOne(mtest.Background, bson.D{})
+		assert.NotNil(mt, err, "expected InsertOne error, got nil")
+
+		we, ok := err.(mongo.WriteException)
+		assert.True(mt, ok, "expected error of type %T, got %v of type %T", mongo.WriteException{}, err, err)
+		wce := we.WriteConcernError
+		assert.NotNil(mt, wce, "expected write concern error, got %v", we)
+
+		var expectedCodeName string
+		if codeNameVal, err := mt.GetSucceededEvent().Reply.LookupErr("writeConcernError", "codeName"); err == nil {
+			expectedCodeName = codeNameVal.StringValue()
+		}
+
+		assert.Equal(mt, expectedCodeName, wce.Name, "expected code name %q, got %q", expectedCodeName, wce.Name)
+	})
+}