(POC) GODRIVER-3690 Extend CommandFailedEvent with error codes

event/monitoring.go

@@ -54,6 +54,7 @@ type CommandSucceededEvent struct {
 type CommandFailedEvent struct {
 	CommandFinishedEvent
 	Failure error
+	Codes   []int32
 }
 
 // CommandMonitor represents a monitor that is triggered for different events.

internal/integration/clam_prose_test.go

@@ -14,9 +14,11 @@ import (
 
 	"go.mongodb.org/mongo-driver/v2/bson"
 	"go.mongodb.org/mongo-driver/v2/internal/assert"
+	"go.mongodb.org/mongo-driver/v2/internal/failpoint"
 	"go.mongodb.org/mongo-driver/v2/internal/integration/mtest"
 	"go.mongodb.org/mongo-driver/v2/internal/integtest"
 	"go.mongodb.org/mongo-driver/v2/internal/logger"
+	"go.mongodb.org/mongo-driver/v2/internal/require"
 	"go.mongodb.org/mongo-driver/v2/mongo"
 	"go.mongodb.org/mongo-driver/v2/mongo/options"
 )
@@ -198,7 +200,6 @@ func clamMultiByteTruncLogs(mt *mtest.T) []truncValidator {
 
 	// Insert started.
 	validators[0] = newTruncValidator(mt, cmd, func(cmd string) error {
-
 		// Remove the suffix from the command string.
 		cmd = cmd[:len(cmd)-len(logger.TruncationSuffix)]
 
@@ -396,3 +397,33 @@ func TestCommandLoggingAndMonitoringProse(t *testing.T) {
 		})
 	}
 }
+
+func TestCommandFailedEvent_Codes(t *testing.T) {
+	clientOpts := options.Client().SetRetryWrites(false)
+
+	mtOpts := mtest.NewOptions().MinServerVersion("8.0").ClientType(mtest.Pinned).ClientOptions(clientOpts)
+	mt := mtest.New(t, mtOpts)
+
+	mt.Run("Top level code", func(mt *mtest.T) {
+		mt.ResetClient(options.Client().SetRetryWrites(false))
+
+		mt.SetFailPoint(failpoint.FailPoint{
+			ConfigureFailPoint: "failCommand",
+			Mode: failpoint.Mode{
+				Times: 1,
+			},
+			Data: failpoint.Data{
+				FailCommands: []string{"insert"},
+				ErrorCode:    1,
+			},
+		})
+
+		_, err := mt.Coll.InsertOne(context.Background(), struct{ X int }{X: 1})
+		require.Error(mt, err, "expected InsertOne error, got nil")
+
+		failedEvent := mt.GetFailedEvent()
+
+		require.NotNil(mt, failedEvent, "expected CommandFailedEvent, got nil")
+		require.Equal(mt, []int32{1}, failedEvent.Codes, "expected Codes to be [1], got %+v", failedEvent.Codes)
+	})
+}

mongo/errors.go

@@ -364,10 +364,12 @@ func hasErrorCode(srvErr ServerError, code int) bool {
 	return false
 }
 
-var _ ServerError = CommandError{}
-var _ ServerError = WriteError{}
-var _ ServerError = WriteException{}
-var _ ServerError = BulkWriteException{}
+var (
+	_ ServerError = CommandError{}
+	_ ServerError = WriteError{}
+	_ ServerError = WriteException{}
+	_ ServerError = BulkWriteException{}
+)
 
 var _ error = ClientBulkWriteException{}
 

x/mongo/driver/errors.go

@@ -566,3 +566,25 @@ func ExtractErrorFromServerResponse(doc bsoncore.Document) error {
 
 	return nil
 }
+
+// errorCodes extracts error codes from a driver.Error representing an ok:0
+// command failure. Since ok:0 indicates the command failed before processing
+// any operations, only a single error code is returned. Returns nil if the
+// error is not a driver.Error (e.g., network errors, WriteCommandError for
+// ok:1 responses).
+//
+// This function may be updated in the future to extract multiple error codes in
+// an ok:1 scenario. In such cases, there can be multiple error codes via
+// WriteErrors which represent individual operation failures within the context
+// of a write command.
+func errorCodes(err error) []int32 {
+	switch e := err.(type) {
+	case Error:
+		return []int32{e.Code}
+	case *Error:
+		if e != nil {
+			return []int32{e.Code}
+		}
+	}
+	return nil
+}

x/mongo/driver/operation.go

@@ -747,7 +747,6 @@ func (op Operation) Execute(ctx context.Context) error {
 		var moreToCome bool
 		var startedInfo startedInformation
 		*wm, moreToCome, startedInfo, err = op.createWireMessage(ctx, maxTimeMS, (*wm)[:0], desc, conn, requestID)
-
 		if err != nil {
 			return err
 		}
@@ -2231,6 +2230,7 @@ func (op Operation) publishFinishedEvent(ctx context.Context, info finishedInfor
 
 	failedEvent := &event.CommandFailedEvent{
 		Failure:              info.cmdErr,
+		Codes:                errorCodes(info.cmdErr),
 		CommandFinishedEvent: finished,
 	}
 	op.CommandMonitor.Failed(ctx, failedEvent)