我有以下实现,其中一切都正常工作,但这行代码存在问题:
lineNumber: line.lineNumber
这一行返回undefined,下面我添加了完整的代码片段,我的问题是:Readline是否提供了一种标准方法来获取行号?或者我必须实现自己的计数器来跟踪行号,这很简单,但如果有标准方式就更好了。
/**
* Search for occurrences of the specified pattern in the received list of files.
* @param filesToSearch - the list of files to search for the pattern
* @returns {Promise} - resolves with the information about the encountered matches for the pattern specified.
*/
const findPattern = (filesToSearch) => {
console.log(filesToSearch);
return new Promise((resolve, reject) => {
var results = [ ];
// iterate over the files
for(let theFile of filesToSearch){
let dataStream = fs.createReadStream(theFile);
let lineReader = readLine.createInterface({
input: dataStream
});
let count = 0; // this would do the trick but I'd rather use standard approach if there's one
// iterates over each line of the current file
lineReader.on('line',(line) => {
count++;
if(line.indexOf(searchPattern) > 0) {
let currLine = line.toString();
currLine = currLine.replace(/{/g, '');//cleanup { from string if present
results.push({
fileName: theFile,
value: currLine,
lineNumber: line.lineNumber //HERE: this results undefined
//lineNumber: count // this does the trick but I'd rather use standard approach.
});
}
});
// resolve the promise once the file scan is finished.
lineReader.on('close', () => resolve(results));
}
});
};