Cannot set key with capitals in it 🤔

[shrinidhi111]

This is my sample Java properties file

keywithallsmall = oldvalue
KeyWithCapitalsInIt = oldvalue

This is my code

package main

import (
	"github.com/spf13/viper"
)

func main() {

	propertiesfile := "test.properties"

	viper.SetConfigFile(propertiesfile)

	viper.ReadInConfig()

	if viper.IsSet("KeyWithCapitalsInIt") {
		viper.Set("KeyWithCapitalsInIt", "newvalue")
	}

	viper.SafeWriteConfigAs("new.properties")

}

And this is the result

keywithallsmall = oldvalue
KeyWithCapitalsInIt = oldvalue
keywithcapitalsinit = newvalue

viper.Set() function declares itself to be "case-insensitive" (to be honest its more like 'convert everything to lower case' instead of real case insensitive) but even then it does not replace the key which I expected it to.

It simply creates a new key with small case.

How do I fix this?