Unmarshal function cannot parse string map stored in environment

nouzun commented 11 months ago

Preflight Checklist

[X] I have searched the issue tracker for an issue that matches the one I want to file, without success.
[X] I am not looking for support or already pursued the available support channels without success.
[X] I have checked the troubleshooting guide for my problem, without success.

Viper Version

1.17.0

Go Version

1.21

Config Source

Environment variables

Format

YAML

Repl.it link

https://replit.com/@nouzun/viperenvunmarshal?v=1#main.go

Code reproducing the issue

package main

import (
  "fmt"
  "strings"
  "os"

  "github.com/spf13/pflag"
  "github.com/spf13/viper"
)

type Conf struct {
  StringMapItem map[string]string `mapstructure:"string-map-item"`
}

func main() {

  viper.Reset()
  viper.SetEnvKeyReplacer(strings.NewReplacer("-", "_"))

  testFlags := &pflag.FlagSet{}
  testFlags.StringToString("string-map-item", nil, "")

  if err := viper.BindEnv("string-map-item", "STRING_MAP_ITEM"); err != nil {
    return
  }

  os.Setenv("STRING_MAP_ITEM", "x=foo,y=boo")

  cfg := &Conf{}
  err := viper.Unmarshal(cfg)
  if err != nil {
    fmt.Println(err)
  }
  fmt.Println(cfg)
}

Expected Behavior

I'd expect viper.Unmarshal to parse "x=foo,y=boo" string into the variable map[string]string

Actual Behavior

viper.Unmarshal returns the following error

'string-map-item' expected a map, got 'string'

Steps To Reproduce

No response

Additional Information

No response

github-actions[bot] commented 11 months ago

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