Golang funcs that wraps json operations with "generics" and fix .0 floats values in marshal process

GenericJsonTools.go

package jst

// Made with <3 by @cambalamas

import (
	"encoding/json"
	"errors"
	"fmt"
	"io/ioutil"
	"log"
	"math"
	"os"
)

// JSONFileToBytes return json as bytes and error if produced while reading
func JSONFileToBytes(filePath string) []byte {
	jsonFile, err := os.Open(filePath)
	if err != nil {
		log.Println(errors.New("ERR_OpeningFile"))
		// TODO : CONTROL ERROR WITH CONTEXT
		return nil
	}
	defer jsonFile.Close()

	jsonBytes, err := ioutil.ReadAll(jsonFile)
	if err != nil {
		log.Println(errors.New("ERR_ReadingFromFile"))
		// TODO : CONTROL ERROR WITH CONTEXT
		return nil
	}

	return jsonBytes
}

// JSONtoOBJ deserialize a json file into go struct
func JSONtoOBJ(jsonFilePath string, obj interface{}) {
	jsonBytes := JSONFileToBytes(jsonFilePath)
	err := json.Unmarshal(jsonBytes, &obj)
	if err != nil {
		log.Println(err)
		log.Println(errors.New("ERR_UnmarshalingJSON"))
		// TODO : CONTROL ERROR WITH CONTEXT
	}
}

// OBJtoJSON serialize a go struct into a json bytes
func OBJtoJSON(obj interface{}) []byte {
	jsonBytes, err := json.Marshal(obj)
	if err != nil {
		log.Println(err)
		log.Println(errors.New("ERR_MarshalingJSON"))
		// TODO : CONTROL ERROR WITH CONTEXT
		return nil
	}
	return jsonBytes
}

// JSONmap parse json file into a map
func JSONmap(filePath string) map[string]interface{} {
	var data map[string]interface{}
	jsonBytes := JSONFileToBytes(filePath)
	json.Unmarshal(jsonBytes, &data)
	return data
}

// Own type for float64 to allow .0 floats
type jFloat64 float64

// MarshalJSON interface implementation for our own float type
// allowing .0 floats
func (jF jFloat64) MarshalJSON() ([]byte, error) {
	const eps = 1e-12
	v := float64(jF)
	w, f := math.Modf(v)
	if f < eps {
		return []byte(fmt.Sprintf(`%v.0`, math.Trunc(w))), nil
	}
	return json.Marshal(v)
}