摩卡咖啡测试.从未导出的名称空间导入类 [英] Mocha test. Import class from not exported namespace

问题描述

我需要为我的 Typescript 应用编写单元测试.我使用 Mocha测试框架. 我的网络应用程序中有内部模块(A)，那里有B类.

I need to write unit test for my Typescript app. I use Mocha test framework. I have got internal module(A) in my web app and class B there.

namespace A {
    export class B {
       constructor() {

       }
    } 
}

我需要为B类编写一些单元测试.

I need to write some unit test for class B.

/// <reference path="path/A.ts" />
import { expect } from 'chai';
    describe('B test', function () {

        describe('#constructor()', () => {
            it('Should create B with default data', () => {
                let b = new A.B();
                expect(b.age).to.equal(90);
            });

        });
    });

我正在使用以下命令开始测试:

I'm starting my tests with command:

mocha --watch  --recursive  path/Tests

但是每次在终端中我都会收到错误消息:

But every time in terminal I receive error message:

ReferenceError: A is not defined

A-是我的内部模块，我无法导出它.以某种方式，如何测试内部模块的B类?

A - is my internal module and I can't to export it. Is it some way, how is it possible to test internal module's class B?

推荐答案

在JavaScript中无法从本地作用域访问变量.基本上，这与以下问题相同:

There is no way to reach variables from local scopes in JavaScript. Basically this is same problem as:

(() => {
  let bar = 1;
})();
// bar cannot be reached from this scope

需要将类重构为可访问的:

The class needs to be refactored to be reachable:

export namespace A {
    export class B {
       constructor() {

       }
    } 
}

此时namespace在这里没有用，只能在ES模块中忽略它.

At this point namespace is of no use here, it can be omitted in favour of ES modules only.

出于可测试性的原因，导出所有内容是一个好习惯.如果某个类被认为是内部类，则将从定义该类的.ts文件中导出，而不是从index.ts中导出.

It is a good practice to export everything for testability reasons. If a class is considered internal, it's exported from .ts file where it was defined but not from index.ts.

/** @internal */ JSDoc注释和stripInternal编译选项可用于从.d.ts声明中排除这些导出.它们将不能作为常规进口产品使用，但仍可以通过require到达.

/** @internal */ JSDoc annotation and stripInternal compilation option can be used to exclude these exports from .d.ts declarations. They won't be available as regular imports but will still be reachable with require.

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