fix: pass compiler to middleware

Author: shellscape

README.md

@@ -49,9 +49,12 @@ const middleware = require('koa-webpack');
 
 const app = new Koa();
 
-app.use(middleware({
-  // options
-}))
+const koaWebpack = require('koa-webpack');
+
+koaWebpack({ .. options .. })
+ .then((middleware) => {
+  app.use(middleware);
+});
 ```
 
 ## API
@@ -84,14 +87,15 @@ this option.
 Example:
 
 ```js
-import Webpack from 'webpack';
-import config from './webpack.config.js';
-
+const webpack = require('webpack');
+const config = require('./webpack.config.js');
 const compiler = Webpack(config);
+const koaWebpack = require('koa-webpack');
 
-app.use(middleware({
-  compiler: compiler
-}))
+koaWebpack({ compiler })
+ .then((middleware) => {
+  app.use(middleware);
+});
 ```
 
 ### config

README.old.md

@@ -23,21 +23,19 @@ const getClient = (compiler, options) => {
   });
 };
 
-const getMiddleware = (devWare, options) => (context, next) =>
+const getMiddleware = (compiler, devWare) => (context, next) =>
   // wait for webpack-dev-middleware to signal that the build is ready
   Promise.all([
     new Promise((resolve, reject) => {
-      const { compiler } = options;
-
-      devWare.waitUntilValid(() => {
-        resolve(true);
-      });
-
       for (const comp of [].concat(compiler.compilers || compiler)) {
         comp.hooks.failed.tap('KoaWebpack', (error) => {
           reject(error);
         });
       }
+
+      devWare.waitUntilValid(() => {
+        resolve(true);
+      });
     }),
 
     // tell webpack-dev-middleware to handle the request
@@ -88,7 +86,7 @@ module.exports = (opts) => {
 
   return getClient(compiler, options).then((client) => {
     const devWare = devMiddleware(compiler, options.devMiddleware);
-    const middleware = getMiddleware(devWare, options);
+    const middleware = getMiddleware(compiler, devWare);
     const close = (callback) => {
       const next = client ? () => client.close(callback) : callback;
       devWare.close(next);