server.js

const Koa = require("koa");
const { resolve } = require("path");
const staticServer = require("koa-static");
const koaBody = require("koa-body");
const cors = require("koa2-cors");
const logger = require("koa-logger");

const app = new Koa();

app.use(staticServer(resolve(__dirname, "./static")));
app.use(koaBody());
app.use(logger());

// 设置跨域
app.use(
  cors({
    origin: function(ctx) {
      if (ctx.url.indexOf("/dooring") > -1) {
        return "*"; // 允许来自所有域名请求
      }
      return "";
    },
    exposeHeaders: ["WWW-Authenticate", "Server-Authorization", "x-test-code"],
    maxAge: 5, //  该字段可选，用来指定本次预检请求的有效期，单位为秒
    credentials: true,
    allowMethods: ["GET", "POST", "PUT", "DELETE", "OPTIONS"],
    allowHeaders: [
      "Content-Type",
      "Authorization",
      "Accept",
      "x-requested-with",
      "Content-Encoding"
    ]
  })
);

let htmlStr = "";

app.use(async (ctx, next) => {
  console.log(ctx.url);
  if (ctx.url === "/dooring/render") {
    htmlStr = ctx.request.body;
    ctx.body = "success";
  } else if (ctx.url.indexOf("/html") === 0) {
    ctx.type = "html";
    ctx.body = htmlStr;
  }
});

app.listen(3000);