plugeth/common/test_utils.go
2015-07-07 14:12:44 +02:00

54 lines
1.5 KiB
Go

// Copyright 2015 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
package common
import (
"encoding/json"
"fmt"
"io/ioutil"
)
// LoadJSON reads the given file and unmarshals its content.
func LoadJSON(file string, val interface{}) error {
content, err := ioutil.ReadFile(file)
if err != nil {
return err
}
if err := json.Unmarshal(content, val); err != nil {
if syntaxerr, ok := err.(*json.SyntaxError); ok {
line := findLine(content, syntaxerr.Offset)
return fmt.Errorf("JSON syntax error at %v:%v: %v", file, line, err)
}
return fmt.Errorf("JSON unmarshal error in %v: %v", file, err)
}
return nil
}
// findLine returns the line number for the given offset into data.
func findLine(data []byte, offset int64) (line int) {
line = 1
for i, r := range string(data) {
if int64(i) >= offset {
return
}
if r == '\n' {
line++
}
}
return
}