node.js - 当目标中已存在具有匹配名称的文件夹时，使用nodejs复制文件夹并为其名称添加后缀

Question

我正在调用Feathers JS API来复制包含一些文件的文件夹。假设我的文件夹名称是'Website1'。

Linux 的正常行为是，它将新文件夹名称附加为'Website1 copy'并进一步附加为'Website1 another copy'、'Website1 3rd copy'等等。

这可以用ShellJS实现吗？

我的代码：

function after_clone_website(hook) {
  return new Promise((resolve, reject) => {
    let sourceProjectName = hook.params.query.sourceProjectName;
    let destinationProjectName = sourceProjectName + '_copy';

    let userDetailId = hook.params.query.userDetailId;

    let response = '';

    response = shell.cp('-Rf', config.path + userDetailId + '/' + 
        sourceProjectName, config.path + userDetailId + '/' +
        destinationProjectName);

    hook.result = response;
    resolve(hook)

  });
}

Answer 1

ShellJS不包含模拟 Linux 相同行为的内置逻辑。即附加；...copy , ...another copy , ...3rd copy , ...4th copy等复制到文件夹名称，当目标路径中的文件夹已存在且与被复制的源文件夹同名时）。

解决方案：

您可以使用带有选项的 ShellJStest()方法-e来检查路径的每个潜在变化是否存在。如果确实存在，则运行您自己的自定义逻辑以确定cp()方法中正确的目标路径值应该是什么。

该自定义逻辑应该是什么？

以下要点包括一个copyDirAndRenameIfExists()接受两个参数的自定义函数；源文件夹的路径，以及目标文件夹的路径（非常类似于 ShellJScp()函数的工作方式）。

var path = require('path'),
    shell = require('shelljs');

/**
 * Copies a given source folder to a given destination folder.
 *
 * To avoid potentially overwriting an exiting destination folder, (i.e. in the
 * scenario whereby a folder already exists in the destination folder with the
 * same name as the source folder), the source folder will be renamed following
 * normal Linux behaviour. I.e. One of the following values will be appended as
 * appropriate: `copy`, `another copy`, `3rd copy`, `4th copy`, etc.
 *
 * @param {String} srcDir - Path to the source directory to copy.
 * @param {String} destDir - Path to the destination directory.
 * @returns {Object} Object returned from invoking the shelljs `cp()` method.
 */
function copyDirAndRenameIfExists(srcDir, destDir) {
    var dirName = path.basename(srcDir),
        newDirName = '',
        hasCopied = false,
        counter = 0,
        response = {};

    /**
     * Helper function suffixes cardinal number with relevent ordinal
     * number suffix. I.e. st, nd, rd, th
     * @param {Number} number - The number to suffix.
     * @returns {String} A number with its ordinal number suffix.
     */
    function addOrdinalSuffix(number) {
        var j = number % 10,
            k = number % 100;

        if (j === 1 && k !== 11) {
            return number + 'st';
        }
        if (j === 2 && k !== 12) {
            return number + 'nd';
        }
        if (j === 3 && k !== 13) {
            return number + 'rd';
        }
        return number + 'th';
    }

    /**
     * Helper function to get the appropriate folder name suffix.
     * @param {Number} num - The current loop counter.
     * @returns {String} The appropriate folder name suffix.
     */
    function getSuffix(number) {
        if (number === 1) {
            return ' copy';
        }
        if (number === 2) {
            return ' another copy';
        }
        return ' ' + addOrdinalSuffix(number) + ' copy';
    }

    /**
     * Helper function copies the source folder recursively to the destination
     * folder if the source directory does not already exist at the destination.
     */
    function copyDir(srcDir, destDir) {
        if (!shell.test('-e', destDir)) {
            response = shell.cp('-R', srcDir, destDir);
            hasCopied = true;
        }
    }

    // Continuously invokes the copyDir() function
    // until the source folder has been copied.
    do {
        if (counter === 0) {
            copyDir(srcDir, path.join(destDir, dirName));
        } else {
            newDirName = dirName + getSuffix(counter);
            copyDir(srcDir, path.join(destDir, newDirName));
        }
        counter += 1;

    } while (!hasCopied);

    return response;
}

执行

1. 将提供的要点（如上）中的函数添加copyDirAndRenameIfExists()到您现有的节点程序中。

2. 确保在程序开始时（如果还没有）还require节点内置path模块（除了）。shelljs即添加以下内容：

    var path = require('path');

3. 最后copyDirAndRenameIfExists()通过更改问题中提供的代码行来调用自定义函数：

   response = shell.cp('-Rf', config.path + userDetailId + '/' +
       sourceProjectName, config.path + userDetailId + '/' + destinationProjectName);
   

   改为：

   response = copyDirAndRenameIfExists(
     path.join(config.path, userDetailId, sourceProjectName),
     path.join(config.path, userDetailId, destinationProjectName)
   };