Question

我有很多中间件。这是其中之一。如何在类型脚本上进行类型一致性和context.state验证来测试我的中间件？


async function internationalizationPlugin(
  context: ParameterizedContext<AppState, AppContext>,
  next: Next
) {
  context.state.i18n = await (i18next as any).createInstance({
    lng: context.state.language,
    fallbackLng: 'en',
  })
  await next()
}

Answer 1

短绒棉衣将检查类型合规性，并将能够对其进行更多自定义。但是，您只需要确保将函数导出到测试文件中，然后运行不是100％复制/可粘贴代码的expect(typeof context).to.be(ParameterizedContext<AppState, AppContext>)，但我认为它是正确的。另外，对于可测试性，如果您从中间件中创建一个类来简化导入和测试，则可能会更容易。

Answer 2

这是我的简单类型支持解决方案。我不确定它是否适合所有人。

import * as httpMocks from 'node-mocks-http'
import * as Koa from 'koa'

export interface MockContext<RequestBody = undefined> extends Koa.Context {
  request: Koa.Context['request'] & {
    body?: RequestBody
  }
}

export const koaMockContext = <
  State = Koa.DefaultState,
  Context = MockContext,
  RequestBody = undefined
>(
  requestBody?: RequestBody
) => {
  const req = httpMocks.createRequest()
  const res = httpMocks.createResponse()
  const app = new Koa<State, Context>()
  const context = app.createContext(req, res) as MockContext<RequestBody> & Koa.ParameterizedContext<State, Context>
  res.statusCode = 404
  context.request.body = requestBody
  return context
}

还有例子

import { AppContext, AppState } from './types'
import { koaMockContext } from './utils'
import { internationalizationPlugin } from '../src/internationalizationPlugin'

describe('internationalizationPlugin', () => {
  const ctx = koaMockContext<AppState, AppContext>()

  it('should not be undefined', async () => {
    await internationalizationPlugin(ctx, async () => {})
    expect(ctx.state.i18n).not.toBe(undefined)
  })
})

如何使用TypeScript测试Koa中间件

2 个答案: