code: function _resolveLineColNumInFile(file, message, options={}){
      if (!message){
          return {line: 0, col: 0}
      }
  
      let fileContent = fs.readFileSync(file, 'utf8')
  
      let beyondPos = 0
  
      switch (typeof options.after){
          case 'string':
              beyondPos = fileContent.indexOf(options.after)
              break
          case 'number':
              beyondPos = options.after
              break
          default:
              break
      }
  
      let pos = fileContent.indexOf(message, beyondPos >= 0 ? beyondPos : 0)
      if (pos <= 0){
          return {line: 0, col: 0}
      }
  
      let lineNum = 1
      let linePos = 0
      for (let i = 0; i < pos; i++){
          if (fileContent.charCodeAt(i) === 10){ // 10: "\n"
              lineNum++
              linePos = i
          }
      }
      
      return {line: lineNum, col: pos - linePos, endCol: pos - linePos + message.length}
  }
docs: Resolve the line num of a message in a file