類型“ReadStream”不可分配給類型“string”.ts(2322)

Question

我正在嘗試運行以下代碼：

const uploadParams = {Bucket: bucketName, Key: '', Body: ''};
const file = '/home/a/bars/img1.png';

const fileStream = fs.createReadStream(file);
fileStream.on('error', function(err) {
  console.log('File Error', err);
});
uploadParams.Body = fileStream;
var path = require('path');
uploadParams.Key = path.basename(file);

但是我在uploadParams.Body = fileStream;收到以下錯誤代碼行：

Type 'ReadStream' is not assignable to type 'string'.ts(2322)

我怎樣才能解決這個問題？

Answer 1

只需指定對象鍵Body可以容納的類型，如下所示：

{ Bucket: string; Key: string; Body: string | ReadStream }

解決方案：

import fs, { ReadStream } from "fs";
import path from "path";

const bucketName = '';
const uploadParams: { Bucket: string; Key: string; Body: string | ReadStream } = {
  Bucket: bucketName,
  Key: '',
  Body: '',
};
const file = '/home/a/bars/img1.png';

const fileStream = fs.createReadStream(file);
fileStream.on('error', function (err) {
  console.log('File Error', err);
});
uploadParams.Body = fileStream;
uploadParams.Key = path.basename(file);

或者如果你使用require你可以使用typeof關鍵字：

// { Bucket: string; Key: string; Body: string | typeof ReadStream } 

const { ReadStream } = require("fs");
const fs = require("fs");
const path = require("path");

const bucketName = '';
const uploadParams: { Bucket: string; Key: string; Body: string | typeof ReadStream } = {
  Bucket: bucketName,
  Key: '',
  Body: '',
};
const file = '/home/a/bars/img1.png';

const fileStream = fs.createReadStream(file);
fileStream.on('error', function (err) {
  console.log('File Error', err);
});
uploadParams.Body = fileStream;
uploadParams.Key = path.basename(file);

雖然我覺得很奇怪，你用一個空字符串來保存一個stream。為什么不干脆呢？

const uploadParams: { Bucket: string; Key: string; Body: null | ReadStream } = {
  Bucket: bucketName,
  Key: '',
  Body: null,
};

演示 - TS 游樂場