时间戳

首页 > 解决方案 > 从文件系统创建对象树

javascript - 从文件系统创建对象树

问题描述

我需要从 CL 参数中获取目录的路径，并创建一个对象树，其中包含所选目录的文件结构。

如果它是一个文件，它的值应该是 true。如果它是一个目录，我应该对该目录做同样的事情（我认为最好的方法是递归）。

输出应如下所示：

{
  file.txt: true,
  directory: {
    one.txt: true,
    two.txt: true,
    ...
  }
  ...
}

到目前为止，我尝试了它的递归版本，但它失败了，不知道为什么。我认为这是因为我没有正确处理代码的异步部分。这是我的代码：

const fs = require("fs");

const basePath = process.argv[2]; //Getting the path (it works)
const result = {};

//Function to check my path is exist and it's a directory
const isDirectory = path => {
  return new Promise((resolve, reject) => {
    fs.lstat(path, (err, stats) => {
      if (err) reject("No such file or Directory");
      resolve(stats.isDirectory());
    });
  });
};

//Recursive function that should create the object tree of the file system
const createTree = (path, target) => {
  return new Promise((resolve, reject) => {
    reject("Promise Oops...");
    fs.readdir(path, (err, data) => {
      data.forEach(item => {
        const currentLocation = `${path}/${item}`;
        isDirectory(currentLocation)
          .then(isDir => {
            if (!isDir) {
              target[item] = true;
              return;
            }

            target[item] = {};
            resolve(createTree(currentLocation, target[item]));
          })
          .catch(err => console.log("Oops in then..."));
      });
    });
  });
};

//Consuming the createTree function
(async () => {
  try {
    const res = await createTree(basePath, result);
    console.log(res);
  } catch (err) {
    console.log("Oops consume...");
  }
})();

标签： javascriptnode.jsobjectrecursionfilesystems

解决方案

您可以使用fs.promisesfs 的基于回调的方法来代替，这可以提高可读性并帮助您轻松找到错误。您正在记录从未createTree定义的函数返回的内容。您应该记录result对象以查看您想要的结果。

const fs = require("fs");

const basePath = process.argv[2]; //Getting the path (it works)
const result = {};

//Function to check my path is exist and it's a directory
const isDirectory = async (path) => {
  try {
    const stats = await fs.promises.lstat(path);
    return stats.isDirectory();
  } catch (error) {
    throw new Error("No such file or Directory");
  }
};

//Recursive function that should create the object tree of the file system
const createTree = async (path, target) => {
  const data = await fs.promises.readdir(path);
  for (const item of data) {
    const currentLocation = `${path}/${item}`;
    const isDir = await isDirectory(currentLocation);
    if (!isDir) {
      target[item] = true;
      continue;
    }
    target[item] = {};
    await createTree(currentLocation, target[item]);
  }
};

//Consuming the createTree function
(async () => {
  try {
    await createTree(basePath, result);
    console.log(result);
  } catch (error) {
    console.log(error.message);
  }
})();

推荐阅读