无法写入.when（）内部的文件？

Question

我对早些时候工作的某些代码有一个疑问，但现在决定它根本不想工作。基本上，我有一个承诺会给我返回一系列数据。我将解释代码底部发生的事情。

function mkdir(path){
    return new Promise(function(resolve,reject){
        fs.mkdir(path, { recursive: true },function(err){
            if(err){console.log(err)}
        })
        return resolve()
    })
}
function writeFile(file,content){
    return new Promise(function(resolve,reject){
        fs.writeFile(file, content, function(err){
            if(err){console.log(err)}
            return resolve()
        })
    })
}


function rawData(socket){
    var mintDataArray = []
    return new Promise(function(){
        for (let i = 1; i < 13; i+= 1) {
            getdat(i).then(function(r){
                //mintDataArray.push(r)
                for(o in r){
                    var dataurls = []
                    dataurls.push(r[o].discord_url,r[o].magic_eden_url,r[o].twitter_url)

                    //socket.emit('twitterFollowers',r[o])
                    const ProjectData = {
                        "mintDate": 0 || "",
                        "name":"",
                        "stock":0,
                        "links":[],
                        "mintTime": 0 || "",
                        "PricePlusDescription":0 || ""
                    }

                    if(r[o].mintDate != null){
                        ProjectData.mintDate = moment.utc(r[o].mintDate).format("MMMM Do")
                    }else{
                        ProjectData.mintDate = "No date specified yet"
                    }
                    

                    ProjectData.name = r[o].name
                    ProjectData.stock = r[o].supply
                    ProjectData.links.push(dataurls) 
                    ProjectData.PricePlusDescription = r[o].price
                    mintDataArray.push(ProjectData)

                }
                
                
            }).then(function(socket){
                //CollectionSorter(mintDataArray)
                for(i in mintDataArray){
                    var data = mintDataArray[i]
                    //console.log(data) // <----- This prints out the data that needs to be written to files.
                    var MintDateFolder = __dirname + "/UpcomingCollections/" +data.mintDate
            
                    if(!fs.existsSync(MintDateFolder)){
                        console.log('huh?')
                        mkdir(__dirname + '/UpcomingCollections/'+data.mintDate)
                    }
                    
                    writeFile(MintDateFolder +"/"+data.name,JSON.stringify(data))
                }


            })
        }
        //socket.emit('twitterFollowers',mintDataArray)
    })
}

因此，该代码应该做的是检查该目录是否首先存在。如果没有，则创建新目录。然后，它应该将文件写入其中（不仅是该目录，还要给其他目录）。如果目录不存在，它不会创建目录，如果我手动创建目录，它甚至不会写入它，但是它确实写入其他目录。我真的不确定这一点，因为我更早地工作了，如果它不存在，它正在创建该目录。所以我不确定我搞砸了。

我最近制作了Mkdir和WriteFile功能，我认为这是问题所在，因为当我有此工作时，我只是在使用fs.mkdir和fs.writefile。但是，我在没有这些功能的情况下再次尝试，但我仍然遇到同样的麻烦。我考虑过另一个承诺检查目录是否存在，但我已经有很多嵌套的承诺。

read（）函数：

function read(i){
    return new Promise(function(resolve,reject){
        var r = https.request(options, function (res) {
            var data = []
            res.on('data', function (d) {
                data.push(d)
            }).on('end', function () {
                var NFTTokenData = []
                console.log(`STATUS: ${res.statusCode}`);
                var info = Buffer.concat(data)
                zlib.gunzip(info,function(err,buf){
                    var NFTData = []
                    var x = buf.toString()
                    var dat = JSON.parse(x)
                    var collectionList = dat.pageProps.__APOLLO_STATE__
                    for(keys in collectionList){
                        if(collectionList[keys].__typename.includes('Nft')){
                            collections.push(collectionList[keys])
                            resolve(collections)
                            
                        }
                        
                    }
                })
            
            })
        })
        r.end()
    })
}

最终解决方案

function Project(fromApi) {
  return {
    mintDate: moment.utc(fromApi.mintDate).format("MMMM Do"),
    name: fromApi.name,
    imageLink:fromApi.project_image_link,
    stock: fromApi.supply,
    links: [
      fromApi.discord_url,
      fromApi.magic_eden_url,
      fromApi.twitter_url
    ],
    price: fromApi.price
  }
}

function write(project, dir) {
  const dest = resolve(dir, join(project.mintDate, project.name))
  console.log(dest)
  return stat(dirname(dest))
    .catch(_ => mkdir(dirname(dest), {recursive: true}))
    .then(_ => writeFile(dest, JSON.stringify(project)))
    .then(_ => project)
}

function rawData(socket){
  return new Promise(function(resolve,reject){
    [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17].map(i => 
      read(i).then(function(r){
      var data = []
      for(i in r){
        if(r[i].__typename == "Nft"){
          data.push(r[i])
        }
      }
      data.map(item => {
        var project = Project(item)
        write(project,"./UpcomingCollections")
      })

      })
    ) 
  })
}

这是下面答案的修改！

Answer 1

您可以在的内部做任何。

让我们谈谈代码中的其他一些问题 -

function mkdir(path){
    return new Promise(function(resolve,reject){
        fs.mkdir(path, { recursive: true },function(err){
            if(err){console.log(err)} // ❌ reject(err); do not log
        })
        return resolve() // ❌ resolve() outside of mkdir callback
    })
}

function writeFile(file,content){
    return new Promise(function(resolve,reject){
        fs.writeFile(file, content, function(err){
            if(err){console.log(err)} // ❌ reject(err); do not log
            return resolve() // ⚠️ "return" not needed
        })
    })
}

您是否觉得在节点中为每个fs函数实现包装器是否乏味？您将很高兴知道 fs/promises 模块已经提供了基于Promise的模块每个API -

import { mkdir, writeFile } from "fs/promises" // ✅

// mkdir(path[, options]) 
// Returns: <Promise> Upon success, fulfills with undefined if recursive is false, or the first directory path created if recursive is true.

// writeFile(file, data[, options])
// Returns: <Promise> Fulfills with undefined upon success.

接下来，我们将在主程序中查看其他问题 -

function rawData(socket){
  var mintDataArray = [] // ⚠️ state "outside" of Promise context
  return new Promise(function(){
    for (let i = 1; i < 13; i+= 1) {
      getdat(i).then(function(r){
        for(o in r){ // ⚠️ global "o"; don't use for..in, use for..of instead
            // ,,,
            mintDataArray.push(Project) // ⚠️ attempting to send state "out" of Promise

        }
        // ⚠️ missing "return"
        // implicitly returning "undefined"
        
      }).then(function(socket){ // ⚠️ function parameter (socket) receives resolved Promise
        for(i in mintDataArray){ // ⚠️ global "i", for..in again, accessing external state
          var data = mintDataArray[i]
          var MintDateFolder = __dirname + "/UpcomingCollections/" +data.mintDate // ⚠️ use "path" module
  
          if(!fs.existsSync(MintDateFolder)){ // ⚠️ async methods until this point, why Sync here?
              console.log('huh?')
              mkdir(__dirname + '/UpcomingCollections/'+data.mintDate) // ⚠️ asynchronous
          }
          
          writeFile(MintDateFolder +"/"+data.name,JSON.stringify(data)) // ⚠️ attempts write before mkdir completes
        }
      })
    }
    socket.emit('twitterFollowers',mintDataArray) // ⚠️ accessing external state
  })
}

阅读和转换数据

这是很多工作，但请放心。通过将大问题分解为小问题，我们可以更聪明，而不是更努力。我们将从重命名getDat重命名为读取开始 -

read(i).then(r => {
  const mintData = [] // state *inside* promise context
  for (const v of r) {
    // for all v of r, add project data to mintData
    mintData.push({
      mintDate: v.mintDate,
      name: v.name,
      stock: v.supply,
      links: [
        v.discord_url,
        v.magic_eden_url,
        v.twitter_url
      ],
      price: v.price
    })
  }
  return mintData // "return" resolves the promise
}).then(...)

我们的已经函数越来越大。提取和构造项目数据有很多代码，因此，请自行函数，project -

function Project(fromApi) {
  // add date logic, or more
  return {
    mintDate: fromApi.mintDate,
    name: fromApi.name,
    stock: fromApi.supply,
    links: [
      fromApi.discord_url,
      fromApi.magic_eden_url,
      fromApi.twitter_url
    ],
    price: fromApi.price
  }
}

read(i).then(r => {
    const mintData = []
    for (const v of r) {
      mintData.push(Project(v)) // ✅
    }
    return mintData
  }).then(...)

相同

read(i)
  .then(r => r.map(Project)) // ✨ no for loop needed!
  .then(...)

- write

这与 您的代码并查看我们的进度 -

function rawData(socket){
  // var mintDataArray = [] // ✅ remove external state
  return new Promise(function(){
    for (let i = 1; i < 13; i+= 1) {
      read(i)
        .then(r => r.map(Project)) // ✨
        .then(function(socket) {
          // ⚠️ remember, "socket" gets the resolved promise
          // since `read` resolves an array of Projects, we should rename it
        })
    }
    // ⚠️ we'll come back to this
    // socket.emit('twitterFollowers',mintDataArray)
  })
}

我们继续使用。这里有很多代码来创建路径，制作目录并将JSON写入文件。让我们使其自己的函数称为write -

import { stat, mkdir, writeFile } from "fs/promises"

import { join, resolve, dirname } from "path" // 

Answer 2

木兰的答案是正确的，我只需要将其他功能中的for循环更改为.map。之后，一切都很好。如下所示，我必须对RAWDATA函数进行一些修改。

function Project(fromApi) {
  return {
    mintDate: moment.utc(fromApi.mintDate).format("MMMM Do"),
    name: fromApi.name,
    imageLink:fromApi.project_image_link,
    stock: fromApi.supply,
    links: [
      fromApi.discord_url,
      fromApi.magic_eden_url,
      fromApi.twitter_url
    ],
    price: fromApi.price
  }
}

function write(project, dir) {
  const dest = resolve(dir, join(project.mintDate, project.name))
  console.log(dest)
  return stat(dirname(dest))
    .catch(_ => mkdir(dirname(dest), {recursive: true}))
    .then(_ => writeFile(dest, JSON.stringify(project)))
    .then(_ => project)
}

function rawData(socket){
  return new Promise(function(resolve,reject){
    [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17].map(i => 
      read(i).then(function(r){
      var data = []
      for(i in r){
        if(r[i].__typename == "Nft"){
          data.push(r[i])
        }
      }
      data.map(item => {
        var project = Project(item)
        write(project,"./UpcomingCollections")
      })

      })
    ) 
  })
}