javascript - TypeScript 在生成的 JavaScript 中列出导入的接口(interface)和类型

Question

我有一个导出类、类型和接口(interface)的模块 A:

export class Event {
    // empty
}

export interface EventHandler {
    handle(event: Event): void
}

export type EventCallback = (event: Event) => void

我可以在另一个模块 B 中使用它:

import {
    EventCallback,
    EventHandler,
    Event
} from "./ts_interface_bug"

let x: EventCallback = (event) => {
    console.log(event)
}

class MyHandler implements EventHandler {
    handle(event: Event): void {
    console.log(event)
    }
}

但编译器在生成 JavaScript (B.js) 时会保留类型:

import { EventCallback, EventHandler, Event } from "./ts_interface_bug.js";
let x = (event) => {
    console.log(event);
};
class MyHandler {
    handle(event) {
        console.log(event);
    }
}

这是错误的 - 没有为类型和接口(interface)生成代码，如您在 A.js 中所见:

export class Event {
}

这是一个错误还是我可以以某种方式配置 TypeScript 编译器以忽略类型和接口(interface)？

typescript 3.5.3

tsconfig-build.json:

"compilerOptions": {
    "allowJs": true,
    "noImplicitAny": true,
    "removeComments": true,
    "preserveConstEnums": true,
    "sourceMap": true,
    "strict": true,
    "strictPropertyInitialization": false,
    "target": "ES2016",
    "lib": [
        "dom", "ES2016"
    ],
    "module": "ES2015",
    "moduleResolution": "node",
    "typeRoots": [
        "./node_modules/@types"
    ],
    "plugins": [
        {
            "transform": "@zoltu/typescript-transformer-append-js-extension/output/index.js"
        }
    ],
},

package.json:

"scripts": {
    "build": "ttsc --build tsconfig-build.json",
},
"devDependencies": {
  "@zoltu/typescript-transformer-append-js-extension": "^1.0.1",
  "ttypescript": "^1.5.7",
  "typescript": "^3.5.3"
}

Answer 1

以上示例在使用 tsc --build tsconfig.json 时有效。 ttypescript 或 typescript-transformer-append-js-extension 插件(在 import 语句中修复 https://github.com/microsoft/TypeScript/issues/16577 )中一定有问题。

我打开了一个错误:https://github.com/Zoltu/typescript-transformer-append-js-extension/issues/3

更新 显然，错误是我需要最后 运行转换器。这修复了它:

"plugins": [
    {
        "transform": "@zoltu/typescript-transformer-append-js-extension/output/index.js",
        "after": true
    }
],