Question

对于节点生成器项目，我想将单词export放在不存在的函数前面。现在，我使用了软件包line-reader，因为它的用法很干净。我认为该程序包不提供读写同一行并将其保存到同一文件的选项。现在，我正在寻找建议或帮助，以了解如何在同一行中实现读写流，或者是创建两个不同流的唯一选择？

所以我要完成的是，当上面的行包含generate时，下一行不包含条件导出。导出应添加到该行的开头。

import fs from 'fs';
import lineReader from 'line-reader';

const curFile : string = 'currentFile.ts'
let nextLine: boolean = false;

lineReader.eachLine(curFile, async (line: string, last: boolean | undefined): Promise<void> => {
    if (nextLine) {
        if(!line.includes('export')){
            const writeStream = fs.createWriteStream(curFile, {
                encoding: 'utf8',
                autoClose: true,
            });
            await writeStream.write(`export ${line}`);
            writeStream.end();
        }
        nextLine = false;
    }

    if (line.includes('generate')) {
        nextLine = true;
    }
});

Answer 1

我这样解决了：

import fs from 'fs';
import lineReader from 'line-reader';

const curFile: string = 'currentFile.ts';
const secFile: string = 'otherFile2.ts'
let nextLine: boolean = false;

const writeStream = fs.createWriteStream(secFile, {
    encoding: 'utf8',
    autoClose: true,
});
lineReader.eachLine(
    curFile,
    async (line: string, last: boolean | undefined): Promise<void> => {
        if (nextLine) {
            if (!line.includes('export')) {
                writeStream.write(`export ${line}`);
            } else {
                writeStream.write(`${line}`);
            }
            nextLine = false;
        }

        // check if line includes generate
        if (line.includes('generate')) {
            nextLine = true;
        }

        // If the last rule has been reached end stream and remove original file and replace it with the sec file.
        if (last) {
            writeStream.end();
            replaceOriginalFile(curFile, secFile)
        }
    },
);


function replaceOriginalFile(originalPath: string, newPath: string) {
    // remove original file
    fs.unlinkSync(originalPath);
    // rename file to replace original
    fs.rename(newPath, originalPath, function(err) {
        if (err) throw err;
    });
}

有没有办法在NodeJS文件流中读取和写入同一行？

1 个答案: