http-svc/src/built-in/fetch.ts

A HTTP request service for browser and node.js

import { IMiddlewareHandler, BuiltInMiddlewareName } from 'types/exports'
import { HttpSvcMiddleware } from '@http-svc/middleware'
import { getBuiltInMiddlewareName, isNode } from '../shared'
/**
 * 客户端fetch（window.fetch）
 * @param ctx
 * @param next
 * @returns
 */
export const fetch: IMiddlewareHandler = async (ctx, next) => {
  if (isNode) {
    throw new Error('When you are in a Node environment, please use server-side fetch middleware.')
  }
  if (!window.fetch) {
    throw new Error('When you are in a non-modern browser, please manually polyfill fetch.')
  }
  if (!ctx.request) return await next()
  if (ctx.response) return await next()
  const { url, method, headers, credentials } = ctx.request
  const body = ctx.request.data as BodyInit | undefined

  const fetchOptions: RequestInit = {
    method
  }

  // 只有当值存在且不为undefined时才添加到fetchOptions中
  if (headers !== undefined) {
    fetchOptions.headers = headers
  }
  if (credentials !== undefined) {
    fetchOptions.credentials = credentials
  }
  if (body !== undefined) {
    fetchOptions.body = body
  }
  if (ctx.abortController?.signal !== undefined) {
    fetchOptions.signal = ctx.abortController.signal
  }

  ctx.response = await window.fetch(url, fetchOptions)

  return await next()
}

export class HttpSvcFetch extends HttpSvcMiddleware {
  static handler = fetch
  handler = fetch
  name: BuiltInMiddlewareName = getBuiltInMiddlewareName('FETCH')
}