github.com/aswedchain/aswed@v1.0.1/common/test_utils.go (about)

     1  // Copyright 2015 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package common
    18  
    19  import (
    20  	"encoding/json"
    21  	"fmt"
    22  	"io/ioutil"
    23  )
    24  
    25  // LoadJSON reads the given file and unmarshals its content.
    26  func LoadJSON(file string, val interface{}) error {
    27  	content, err := ioutil.ReadFile(file)
    28  	if err != nil {
    29  		return err
    30  	}
    31  	if err := json.Unmarshal(content, val); err != nil {
    32  		if syntaxerr, ok := err.(*json.SyntaxError); ok {
    33  			line := findLine(content, syntaxerr.Offset)
    34  			return fmt.Errorf("JSON syntax error at %v:%v: %v", file, line, err)
    35  		}
    36  		return fmt.Errorf("JSON unmarshal error in %v: %v", file, err)
    37  	}
    38  	return nil
    39  }
    40  
    41  // findLine returns the line number for the given offset into data.
    42  func findLine(data []byte, offset int64) (line int) {
    43  	line = 1
    44  	for i, r := range string(data) {
    45  		if int64(i) >= offset {
    46  			return
    47  		}
    48  		if r == '\n' {
    49  			line++
    50  		}
    51  	}
    52  	return
    53  }