GODRIVER-2774 Refactor replaceErrors to always wrap errors instead of replacing them.

internal/codecutil/encoding.go

@@ -28,10 +28,12 @@ type MarshalError struct {
 
 // Error implements the error interface.
 func (e MarshalError) Error() string {
-	return fmt.Sprintf("cannot transform type %s to a BSON Document: %v",
+	return fmt.Sprintf("cannot marshal type %q to a BSON Document: %v",
 		reflect.TypeOf(e.Value), e.Err)
 }
 
+func (e MarshalError) Unwrap() error { return e.Err }
+
 // EncoderFn is used to functionally construct an encoder for marshaling values.
 type EncoderFn func(io.Writer) *bson.Encoder
 

mongo/change_stream.go

@@ -376,15 +376,15 @@ AggregateExecuteLoop:
 		}
 	}
 	if err != nil {
-		cs.err = replaceErrors(err)
+		cs.err = wrapErrors(err)
 		return cs.err
 	}
 
 	cr := cs.aggregate.ResultCursorResponse()
 	cr.Server = server
 
 	cs.cursor, cs.err = driver.NewBatchCursor(cr, cs.sess, cs.client.clock, cs.cursorOptions)
-	if cs.err = replaceErrors(cs.err); cs.err != nil {
+	if cs.err = wrapErrors(cs.err); cs.err != nil {
 		return cs.Err()
 	}
 
@@ -597,13 +597,13 @@ func (cs *ChangeStream) Decode(val interface{}) error {
 // Err returns the last error seen by the change stream, or nil if no errors has occurred.
 func (cs *ChangeStream) Err() error {
 	if cs.err != nil {
-		return replaceErrors(cs.err)
+		return wrapErrors(cs.err)
 	}
 	if cs.cursor == nil {
 		return nil
 	}
 
-	return replaceErrors(cs.cursor.Err())
+	return wrapErrors(cs.cursor.Err())
 }
 
 // Close closes this change stream and the underlying cursor. Next and TryNext must not be called after Close has been
@@ -619,7 +619,7 @@ func (cs *ChangeStream) Close(ctx context.Context) error {
 		return nil // cursor is already closed
 	}
 
-	cs.err = replaceErrors(cs.cursor.Close(ctx))
+	cs.err = wrapErrors(cs.cursor.Close(ctx))
 	cs.cursor = nil
 	return cs.Err()
 }
@@ -678,7 +678,7 @@ func (cs *ChangeStream) next(ctx context.Context, nonBlocking bool) bool {
 	if len(cs.batch) == 0 {
 		cs.loopNext(ctx, nonBlocking)
 		if cs.err != nil {
-			cs.err = replaceErrors(cs.err)
+			cs.err = wrapErrors(cs.err)
 			return false
 		}
 		if len(cs.batch) == 0 {
@@ -719,7 +719,7 @@ func (cs *ChangeStream) loopNext(ctx context.Context, nonBlocking bool) {
 			return
 		}
 
-		cs.err = replaceErrors(cs.cursor.Err())
+		cs.err = wrapErrors(cs.cursor.Err())
 		if cs.err == nil {
 			// Check if cursor is alive
 			if cs.ID() == 0 {

mongo/client.go

@@ -239,7 +239,7 @@ func newClient(opts ...*options.ClientOptions) (*Client, error) {
 	if client.deployment == nil {
 		client.deployment, err = topology.New(cfg)
 		if err != nil {
-			return nil, replaceErrors(err)
+			return nil, wrapErrors(err)
 		}
 	}
 
@@ -261,7 +261,7 @@ func (c *Client) connect() error {
 	if connector, ok := c.deployment.(driver.Connector); ok {
 		err := connector.Connect()
 		if err != nil {
-			return replaceErrors(err)
+			return wrapErrors(err)
 		}
 	}
 
@@ -293,7 +293,7 @@ func (c *Client) connect() error {
 	if subscriber, ok := c.deployment.(driver.Subscriber); ok {
 		sub, err := subscriber.Subscribe()
 		if err != nil {
-			return replaceErrors(err)
+			return wrapErrors(err)
 		}
 		updateChan = sub.Updates
 	}
@@ -350,7 +350,7 @@ func (c *Client) Disconnect(ctx context.Context) error {
 	}
 
 	if disconnector, ok := c.deployment.(driver.Disconnector); ok {
-		return replaceErrors(disconnector.Disconnect(ctx))
+		return wrapErrors(disconnector.Disconnect(ctx))
 	}
 
 	return nil
@@ -381,7 +381,7 @@ func (c *Client) Ping(ctx context.Context, rp *readpref.ReadPref) error {
 		{"ping", 1},
 	}, options.RunCmd().SetReadPreference(rp))
 
-	return replaceErrors(res.Err())
+	return wrapErrors(res.Err())
 }
 
 // StartSession starts a new session configured with the given options.
@@ -434,7 +434,7 @@ func (c *Client) StartSession(opts ...options.Lister[options.SessionOptions]) (*
 
 	sess, err := session.NewClientSession(c.sessionPool, c.id, coreOpts)
 	if err != nil {
-		return nil, replaceErrors(err)
+		return nil, wrapErrors(err)
 	}
 
 	return &Session{
@@ -741,7 +741,7 @@ func (c *Client) ListDatabases(ctx context.Context, filter interface{}, opts ...
 
 	err = op.Execute(ctx)
 	if err != nil {
-		return ListDatabasesResult{}, replaceErrors(err)
+		return ListDatabasesResult{}, wrapErrors(err)
 	}
 
 	return newListDatabasesResultFromOperation(op.Result()), nil
@@ -965,7 +965,7 @@ func (c *Client) BulkWrite(ctx context.Context, writes []ClientBulkWrite,
 	op.result.Acknowledged = acknowledged
 	op.result.HasVerboseResults = !op.errorsOnly
 	err = op.execute(ctx)
-	return &op.result, replaceErrors(err)
+	return &op.result, wrapErrors(err)
 }
 
 // newLogger will use the LoggerOptions to create an internal logger and publish

mongo/collection.go

@@ -248,7 +248,7 @@ func (coll *Collection) BulkWrite(ctx context.Context, models []WriteModel,
 
 	err = op.execute(ctx)
 
-	return &op.result, replaceErrors(err)
+	return &op.result, wrapErrors(err)
 }
 
 func (coll *Collection) insert(
@@ -1049,15 +1049,15 @@ func aggregate(a aggregateParams, opts ...options.Lister[options.AggregateOption
 		if errors.As(err, &wce) && wce.WriteConcernError != nil {
 			return nil, *convertDriverWriteConcernError(wce.WriteConcernError)
 		}
-		return nil, replaceErrors(err)
+		return nil, wrapErrors(err)
 	}
 
 	bc, err := op.Result(cursorOpts)
 	if err != nil {
-		return nil, replaceErrors(err)
+		return nil, wrapErrors(err)
 	}
 	cursor, err := newCursorWithSession(bc, a.client.bsonOpts, a.registry, sess)
-	return cursor, replaceErrors(err)
+	return cursor, wrapErrors(err)
 }
 
 // CountDocuments returns the number of documents in the collection. For a fast count of the documents in the
@@ -1132,7 +1132,7 @@ func (coll *Collection) CountDocuments(ctx context.Context, filter interface{},
 
 	err = op.Execute(ctx)
 	if err != nil {
-		return 0, replaceErrors(err)
+		return 0, wrapErrors(err)
 	}
 
 	batch := op.ResultCursorResponse().FirstBatch
@@ -1213,7 +1213,7 @@ func (coll *Collection) EstimatedDocumentCount(
 	op.Retry(retry)
 
 	err = op.Execute(ctx)
-	return op.Result().N, replaceErrors(err)
+	return op.Result().N, wrapErrors(err)
 }
 
 // Distinct executes a distinct command to find the unique values for a specified field in the collection.
@@ -1302,7 +1302,7 @@ func (coll *Collection) Distinct(
 
 	err = op.Execute(ctx)
 	if err != nil {
-		return &DistinctResult{err: replaceErrors(err)}
+		return &DistinctResult{err: wrapErrors(err)}
 	}
 
 	arr, ok := op.Result().Values.ArrayOK()
@@ -1504,12 +1504,12 @@ func (coll *Collection) find(
 	op = op.Retry(retry)
 
 	if err = op.Execute(ctx); err != nil {
-		return nil, replaceErrors(err)
+		return nil, wrapErrors(err)
 	}
 
 	bc, err := op.Result(cursorOpts)
 	if err != nil {
-		return nil, replaceErrors(err)
+		return nil, wrapErrors(err)
 	}
 	return newCursorWithSession(bc, coll.bsonOpts, coll.registry, sess)
 }
@@ -1560,7 +1560,7 @@ func (coll *Collection) FindOne(ctx context.Context, filter interface{},
 		cur:      cursor,
 		bsonOpts: coll.bsonOpts,
 		reg:      coll.registry,
-		err:      replaceErrors(err),
+		err:      wrapErrors(err),
 	}
 }
 
@@ -2044,7 +2044,7 @@ func (coll *Collection) drop(ctx context.Context) error {
 	// ignore namespace not found errors
 	var driverErr driver.Error
 	if !errors.As(err, &driverErr) || !driverErr.NamespaceNotFound() {
-		return replaceErrors(err)
+		return wrapErrors(err)
 	}
 	return nil
 }

mongo/cursor.go

@@ -194,7 +194,7 @@ func (c *Cursor) next(ctx context.Context, nonBlocking bool) bool {
 		// If we don't have a next batch
 		if !c.bc.Next(ctx) {
 			// Do we have an error? If so we return false.
-			c.err = replaceErrors(c.bc.Err())
+			c.err = wrapErrors(c.bc.Err())
 			if c.err != nil {
 				return false
 			}
@@ -289,7 +289,7 @@ func (c *Cursor) Err() error { return c.err }
 // the first call, any subsequent calls will not change the state.
 func (c *Cursor) Close(ctx context.Context) error {
 	defer c.closeImplicitSession()
-	return replaceErrors(c.bc.Close(ctx))
+	return wrapErrors(c.bc.Close(ctx))
 }
 
 // All iterates the cursor and decodes each document into results. The results parameter must be a pointer to a slice.
@@ -336,7 +336,7 @@ func (c *Cursor) All(ctx context.Context, results interface{}) error {
 		batch = c.bc.Batch()
 	}
 
-	if err = replaceErrors(c.bc.Err()); err != nil {
+	if err = wrapErrors(c.bc.Err()); err != nil {
 		return err
 	}
 

mongo/database.go

@@ -288,7 +288,7 @@ func (db *Database) RunCommandCursor(
 	op, sess, err := db.processRunCommand(ctx, runCommand, true, opts...)
 	if err != nil {
 		closeImplicitSession(sess)
-		return nil, replaceErrors(err)
+		return nil, wrapErrors(err)
 	}
 
 	if err = op.Execute(ctx); err != nil {
@@ -297,16 +297,16 @@ func (db *Database) RunCommandCursor(
 			return nil, errors.New(
 				"database response does not contain a cursor; try using RunCommand instead")
 		}
-		return nil, replaceErrors(err)
+		return nil, wrapErrors(err)
 	}
 
 	bc, err := op.ResultCursor()
 	if err != nil {
 		closeImplicitSession(sess)
-		return nil, replaceErrors(err)
+		return nil, wrapErrors(err)
 	}
 	cursor, err := newCursorWithSession(bc, db.bsonOpts, db.registry, sess)
-	return cursor, replaceErrors(err)
+	return cursor, wrapErrors(err)
 }
 
 // Drop drops the database on the server. This method ignores "namespace not found" errors so it is safe to drop
@@ -347,7 +347,7 @@ func (db *Database) Drop(ctx context.Context) error {
 
 	var driverErr driver.Error
 	if err != nil && (!errors.As(err, &driverErr) || !driverErr.NamespaceNotFound()) {
-		return replaceErrors(err)
+		return wrapErrors(err)
 	}
 	return nil
 }
@@ -497,16 +497,16 @@ func (db *Database) ListCollections(
 	err = op.Execute(ctx)
 	if err != nil {
 		closeImplicitSession(sess)
-		return nil, replaceErrors(err)
+		return nil, wrapErrors(err)
 	}
 
 	bc, err := op.Result(cursorOpts)
 	if err != nil {
 		closeImplicitSession(sess)
-		return nil, replaceErrors(err)
+		return nil, wrapErrors(err)
 	}
 	cursor, err := newCursorWithSession(bc, db.bsonOpts, db.registry, sess)
-	return cursor, replaceErrors(err)
+	return cursor, wrapErrors(err)
 }
 
 // ListCollectionNames executes a listCollections command and returns a slice containing the names of the collections
@@ -944,7 +944,7 @@ func (db *Database) executeCreateOperation(ctx context.Context, op *operation.Cr
 		Deployment(db.client.deployment).
 		Crypt(db.client.cryptFLE)
 
-	return replaceErrors(op.Execute(ctx))
+	return wrapErrors(op.Execute(ctx))
 }
 
 // GridFSBucket is used to construct a GridFS bucket which can be used as a