Javascript/Typescript 中类的交叉引用如何工作？

问题描述

我在交叉引用类时遇到问题，即使它们是在一个文件中定义的。

// classes.ts
export class A extends BaseModel implements IA {
  static readonly modelName = 'A';
  b?: B;
  symbol?: string;

  constructor(object: IA | A = {} as IA) {
    super(object);
    const { symbol,b } = object as A;
    this.symbol = symbol;
    this.b = b;
  }
}


export class B extends BaseModel implements IB {
  static readonly modelName = 'B';
  a?: A[];
  constructor(object: IB | B = {} as IB) {
    super(object);
    const { a } = object as B;
    this.a = a as A[];
  }
}

错误是这样的

Uncaught ReferenceError: Cannot access 'B' before initialization
    at Module.../../../../libs/platform/src/data/models/common/uom.ts (uom.ts:13)
    at __webpack_require__ (bootstrap:84)
    at Module.../../../../libs/platform/src/data/models/common/common-models.ts (main.js:27248)
    at __webpack_require__ (bootstrap:84)
    at Module.../../../../libs/platform/src/data/models/common/index.ts (index.ts:1)
    at __webpack_require__ (bootstrap:84)
    at Module.../../../../libs/platform/src/data/models/index.ts (index.ts:1)
    at __webpack_require__ (bootstrap:84)
    at Module.../../../../libs/platform/src/data/index.ts (index.ts:1)
    at __webpack_require__ (bootstrap:84)
    at Module.../../../../libs/platform/src/index.ts (index.ts:1)
    at __webpack_require__ (bootstrap:84)
    at Module.../../../../libs/platform-frontend/src/core/client/frontend-client.ts (index.ts:1)
    at __webpack_require__ (bootstrap:84)
    at Module.../../../../libs/platform-frontend/src/core/client/index.ts (index.ts:1)
    at __webpack_require__ (bootstrap:84)

这里是 babel 和 tsconfig 文件

// babel.config.json
{
  "presets": [
    "@nrwl/web/babel","@nrwl/react/babel"
  ],"plugins": [
    "babel-plugin-transform-typescript-Metadata"
  ],"babelrcRoots": [
    "*"
  ]
}

//tsconfig.json

{
  "compileOnSave": false,"compilerOptions": {
    "downlevelIteration": true,"types": ["jest","node","cypress","reflect-Metadata"],"resolveJsonModule": true,"esModuleInterop": true,"rootDir": ".","sourceMap": false,"declaration": false,"moduleResolution": "node","emitDecoratorMetadata": true,"experimentalDecorators": true,"skipLibCheck": true,"importHelpers": false,"target": "es5","allowJs": true,"typeRoots": ["node_modules/@types"],"lib": [
      "es2017","es6","dom","es2016","esnext.asynciterable","es5","scripthost","es2015.promise","es2015.collection"
    ],"baseUrl": ".","forceConsistentCasingInFileNames": true,"noImplicitReturns": true,"suppressImplicitAnyIndexErrors": true,"noUnusedLocals": true,...
    ...
}

令人困惑的是它根据 babel 配置正常工作 我正在尝试在我的代码库中添加 inversify，因为我必须在 babel 配置中添加 babel-plugin-transform-typescript-metadata。 这样做之后，我在每个带有交叉引用的类上都会出错，这些错误在添加 babel 插件之前工作正常

• 是什么导致了这些问题？
• 如何根据 babel 配置正常工作？
• 我该怎么做才能修复它，因为它甚至不在可能导致循环依赖的单独文件中

解决方法

显然是与“babel-plugin-transform-typescript-metadata”相关的问题，用“babel-plugin-parameter-decorator”替换该插件后，与循环依赖相关的问题自动解决。