How to run the Node.js script while running NPM run XXX

Write copyfile.js script implementation, copy all files and sub-folders in the folder to another folder

Notice copyfile. js belongs to the back-end script and needs to run node copyfile. js

• Introduce two modules in the Node environment write file module and read file module

  const fs = require('fs');
  const path = require('path');
  Copy the code

• The following two pieces of code are integrated: this is done by directly calling the copyFolde function (relative path of source file, relative path of copy target)

  • Copy the source file to the destination file:

    / /! Copy files from the srcPath path to the tarPath CD as a callback
    var copyFile = function(srcPath, tarPath, cb) {
      var rs = fs.createReadStream(srcPath);
      rs.on('error'.function(err) {
        if (err) {
          console.log('read error', srcPath);
        }
        cb && cb(err);
      })
     
      var ws = fs.createWriteStream(tarPath);
      ws.on('error'.function(err) {
        if (err) {
          console.log('write error', tarPath);
        }
        cb && cb(err);
      })
      ws.on('close'.function(ex) {
        cb && cb(ex);
      })
     
      rs.pipe(ws);
    }
    ​
    Copy the code

  • Copy all files and subfolders in the source folder to the target folder

    / /! To recursively copy files and folders under srcDir to CD under tarDir is a callback
    var copyFolder = function(srcDir, tarDir, cb) {
      fs.readdir(srcDir, function(err, files) {
        var count = 0;
        var checkEnd = function() {
          ++count == files.length && cb && cb();
        }
     
        if (err) {
          checkEnd();
          return;
        }
     
        files.forEach(function(file) {
          var srcPath = path.join(srcDir, file);
          var tarPath = path.join(tarDir, file);
     
          fs.stat(srcPath, function(err, stats) {
            if (stats.isDirectory()) {
              console.log('mkdir', tarPath);
              fs.mkdir(tarPath, function(err) {
                if (err) {
                  console.log(err);
                  return;
                }
     
                copyFolder(srcPath, tarPath, checkEnd);
              });
            } else{ copyFile(srcPath, tarPath, checkEnd); }}); });// Directly callback when empty
        files.length === 0 && cb && cb();
      });
    }
    ​
    Copy the code

• Node.js is a back-end script written based on Node.js. How to run the back-end script in a Vue project? It is known that the Vue project is executed NPM run XXX and the command of copyfile.js is node copyfile.js

  • Option 1: Open it in the same projectTwo command line WindowsPerformed, respectively,npm run xxx 和 node copyFile.jsEffects work in the same project

• Plan 1 is too troublesome to open two Windows and execute two commands. Is there a way to achieve the effect of plan 1 simply by executing the NPM run XXX command

  • NPM run XXX: executes scripts written in scripts in pakeage.json, which are the file names in node_modules/.bin

  • Solution 2: Configure multiple commands in package.json

    If the command contains Spaces, use () to include the command. In addition && && and the role of the different.

     "scripts": {
        "serve": "(node copyFile.js) && (vue-cli-service serve)"."start": "webpack & (ng serve)"
      },
    Copy the code

    • The ➊ command executed successfully. To perform firstnode copyFile.jsRun the command after the command is executedvue-cli-service serve
    • “The call by bananas was carried out simultaneously. At the same time to performwebpackAs well asng serveTwo commands

Note: the above method will only copy the file if you want to modify it later. After executing the command to overwrite the target file, you need to use # sync-copydir. After executing the command, no prompt is displayed in the COMMAND line window. You need to check whether the file is overwritten successfully.