gofr-dev/gofr · error

incorrect file type

Error message

incorrect file type

What it means

errIncorrectFileType is the sentinel returned by (*FileSystem).Rename when the old and new names are not of the same type — specifically when a file is renamed with a new name whose extension differs from the old one. S3 has no real rename, so the implementation copies + deletes, and it refuses cross-type renames rather than guessing intent.

Source

Thrown at pkg/gofr/datasource/file/s3/fs.go:26

	"mime"
	"os"
	"path"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	awsConfig "github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/credentials"
	"github.com/aws/aws-sdk-go-v2/service/s3"
	file "gofr.dev/pkg/gofr/datasource/file"
)

const (
	typeFile      = "file"
	typeDirectory = "directory"
)

var (
	errIncorrectFileType = errors.New("incorrect file type")
)

// client struct embeds the *s3.Client.
type client struct {
	*s3.Client
}

type FileSystem struct {
	s3File    S3File
	conn      s3Client
	presigner s3Presigner
	config    *Config
	logger    Logger
	metrics   Metrics
}

// Config represents the s3 configuration.
type Config struct {

View on GitHub (pinned to 187eb24962)

Solutions

1. Keep the same extension in the new name: strip only the base name portion.
2. If a format/type change is really intended, copy the object to the new key with the new extension via your own CopyObject call instead of Rename.
3. If the extension is semantically meaningless in your bucket layout, name files without extensions consistently (note: an empty extension is treated as a directory here).

Example fix

// before
fs.Rename("bucket/report.txt", "bucket/report-final.csv") // error
// after
fs.Rename("bucket/report.txt", "bucket/report-final.txt")

func canRename(old, new string) bool {
    return path.Ext(old) == path.Ext(new)
}
// guard:
if !canRename(oldName, newName) { /* fix newName before calling Rename */ }

if err := fs.Rename(old, new); err != nil {
    if strings.Contains(err.Error(), "incorrect file type") {
        // keep the original extension and retry
    }
    return err
}

When it happens

Trigger: Calling Rename(oldname, newname) where path.Ext(oldname) != path.Ext(newname) and the old name is a file (non-empty extension), e.g. Rename("bucket/a.txt", "bucket/a.json").

Common situations: Renaming a file and accidentally changing its extension; code that rewrites names with a different suffix; converting formats via 'rename' instead of copy+transform.

Related errors

• %w: negative offset %d
• out of range
• %w: renaming as well as moving file to different location is
• %w: new filename must match the old file's type
• operation not permitted

AI-assisted analysis of gofr-dev/gofr@187eb24962 (2026-09-01). Data as JSON: /api/errors/6fcc76420380bb52. Report an issue: GitHub.