Embed does not respect Windows filepaths
Closed this issue · 2 comments
200sc commented
What version of Go are you using (go version
)?
$ go version go version go1.16 windows/amd64
Does this issue reproduce with the latest release?
Yes, it is introduced by the latest release, which introduced embed
What operating system and processor architecture are you using (go env
)?
go env
Output
$ go env set GOARCH=amd64 set GOHOSTARCH=amd64 set GOHOSTOS=windows
What did you do?
With a file at ./assets/test.json
:
package main
import (
"embed"
"fmt"
"io/ioutil"
"path/filepath"
)
//go:embed assets/*
var assets embed.FS
func main() {
path := filepath.Join("assets", "test.json")
data, err := ioutil.ReadFile(path)
if err != nil {
fmt.Println("error reading real file:", err)
return
}
fmt.Println(string(data))
data, err = assets.ReadFile(path)
if err != nil {
fmt.Println("error reading embedded file:", err)
return
}
fmt.Println(string(data))
}
What did you expect to see?
$ go run main.go
{"hello":"world"}
{"hello":"world"}
What did you see instead?
$ go run main.go
{"hello":"world"}
error reading embedded file: open assets\test.json: file does not exist
We can infer this is a path problem because if we instead do:
path = strings.ReplaceAll(path, "\\", "/")
data, err = assets.ReadFile(path)
Then the embed call succeeds.
I tested this with cmd and bash, and both exhibited this behavior.
eliasnaur commented
The io/fs.FS package uses forward slashes for filenames, even on Windows. See https://golang.org/pkg/io/fs/#ValidPath:
"Note that paths are slash-separated on all systems, even Windows."
You should use path.Join, not filepath.Join for embed filenames.
200sc commented
It seems really unfortunate that embed doesn't accept filepaths used by the OS-- it almost feels like using path/filepath
at all is a bad idea now.
But if that's what's decided, that's what's decided.