fs.readdir深度= 1的递归搜索

Question

I have to write a code which takes one parameter ie path to directory, fetch files from the given directory and again does the same for the directories inside the given directory.The whole search should be wrapped in a promise.

But the depth of recursive search is 1.

Final array should look like: [file1, file2, file3, [file1inDir1, file2inDir1, Dir1inDir1, file3inDir1, Dir2inDir1], file4, file5]

My code is:

const fs = require("fs");
const path = require("path");

function checkfile(files){
let result = [];
for(let i=0 ; i<files.length ;i++){
  let newpath = path.join(__dirname,files[i]);
   fs.stat(newpath, (err,stats)=>{
    if(stats.isDirectory()){
    fs.readdir(newpath, (error,files)=>{result.push(files)})
    }
    else{result.push(files[i])}
  })
}
return result;
}

let test = (filepath) => {
    return new Promise((resolve, reject) =>{
    fs.readdir(filepath, (error,files) => {
        if (error) {
        reject("Error occured while reading directory");
     } else {
     resolve(checkfile(files)); 
    }
   });
 }
)}

test(__dirname)
  .then(result => {
    console.log(result);
  })
  .catch(er => {
    console.log(er);
  });

When I run it I get the following output: []

How do I correct this?

Answer 1

test correctly returns a promise, but checkfile does not , thus all the async operations happen after the yet empty result array was synchronously returned.

Fortunately NodeJS already provides utilities that return promises instead of taking callbacks docs , with them writing that code without callbacks going wrong is easy:

 async function checkfile(files){
   const  result = [];
   for(let i=0 ; i<files.length ;i++){
    let newpath = path.join(__dirname,files[i]);
    const stats = await fs.promises.stat(newpath);
    if(stats.isDirectory()){
     const files = await fs.promises.readdir(newpath);
     result.push(files);
    } else result.push(files[i]);
  }    
  return result;
}

async function test(filepath) {    
  const files = await fs.promises.readdir(filepath);
  return checkfile(files);
}