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javascript - 打字稿找不到模块'./lib'

问题描述

我正在尝试在 Typescript 的服务器端应用程序中使用winston-aws-cloudwatch库。

如果您想重现该问题，我在 GitHub 上有一个SSCCE 设置。这是细节。

索引.ts

import logger  from './logger';
logger.info(` logger is up !!`);

记录器.ts

import winston from 'winston';
import CloudWatchTransport from 'winston-aws-cloudwatch';

const logger = winston.createLogger();
logger.add(new CloudWatchTransport({logGroupName:'my-api', logStreamName: 'lstream'}));
logger.level = 'silly';

export default logger;

tsconfig.json

{
    "compilerOptions": {
    "target": "es2017" ,
    "module": "commonjs" ,
    "lib": [
        "es2017",
        "esnext.asynciterable"
    ] ,
    "allowJs": true ,
    "sourceMap": true ,
    "outDir": "./dist" ,    
    "noUnusedLocals": true ,
    "noUnusedParameters": true ,
    "noImplicitReturns": true ,
    "noFallthroughCasesInSwitch": true ,
    "moduleResolution": "node" ,
    "baseUrl": "./" ,
    "paths": {
        "*": ["node_modules/*", "src/types/*"]
    } ,
    "allowSyntheticDefaultImports": true ,
    "esModuleInterop": true 
    }
}

包.json

{
  "name": "winston-aws",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "ts-node index.js",
    "watch-node": "nodemon dist/index.js",
    "watch": "concurrently -k -p \"[{name}]\" -n \"TypeScript,Node\" -c \"yellow.bold,cyan.bold\" \"npm run watch-ts\" \"npm run watch-node\"",
    "watch-test": "npm run test -- --watchAll",
    "build-ts": "tsc",
    "watch-ts": "tsc --traceResolution -w"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "babel-cli": "^6.26.0",
    "winston": "^3.0.0",
    "winston-aws-cloudwatch": "^2.0.0"
  },
  "devDependencies": {
    "@types/node": "^10.3.3",
    "babel-preset-env": "^1.7.0",
    "concurrently": "^3.5.1",
    "nodemon": "^1.17.5",
    "ts-node": "^6.1.1",
    "typescript": "^2.9.2"
  }
}

当我尝试使用运行应用程序时，npm run watch我得到：

[Node] internal/modules/cjs/loader.js:596
[Node]     throw err;
[Node]     ^
[Node]
[Node] Error: Cannot find module './lib/'
[Node]     at Function.Module._resolveFilename (internal/modules/cjs/loader.js:594:15)
[Node]     at Function.Module._load (internal/modules/cjs/loader.js:520:25)
[Node]     at Module.require (internal/modules/cjs/loader.js:650:17)
[Node]     at require (internal/modules/cjs/helpers.js:20:18)
[Node]     at Object.<anonymous> (/Users/nishant/dev/sscce/dist/node_modules/winston-aws-cloudwatch/index.js:1:80)
[Node]     at Module._compile (internal/modules/cjs/loader.js:702:30)
[Node]     at Object.Module._extensions..js (internal/modules/cjs/loader.js:713:10)
[Node]     at Module.load (internal/modules/cjs/loader.js:612:32)
[Node]     at tryModuleLoad (internal/modules/cjs/loader.js:551:12)
[Node]     at Function.Module._load (internal/modules/cjs/loader.js:543:3)

如果您按照执行，似乎 Typescript 能够解析路径：

[TypeScript] ======== Module name './lib/' was successfully resolved to '/Users/nishant/dev/sscce/node_modules/winston-aws-cloudwatch/lib/index.js'. ========

但我看到node_modules/winston-aws-cloudwatch有一个lib目录而dist/node_modules/winston-aws-cloudwatch没有。

在这一点上，我不知道出了什么问题。

标签： javascripttypescripttsc

解决方案

啊! 因此，经过多次试验和错误，结果发现主要的罪魁祸首是：

 "allowJs": true ,

出于某种原因，它正在将某些部分复制node_modules到./dist其中一个文件中，正如您在错误中看到的那样：

dist/node_modules/winston-aws-cloudwatch/index.js

现在问题有两个

  1. 我不知道是否node_modules应该复制到dist. 我认为这一切都应该过去。这是错误的。

    一个都不要node_modules进去dist，编译后的文件要参考paths找出位置node_modules。

  2. 第二个问题是当我痛苦地打开和关闭所有tsconfig选项并重新运行构建时，我看不到错误消失。原因是，dist不清除。在无数次重复相同的过程时，我凭着一种晦涩的运气想到了这一点！

总之，好好学习。希望有一天它会帮助某人。

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