Code refactoring

lib/express.js

@@ -1,14 +1,7 @@
 'use strict'
 
-const restc = require('./restc')
+const serve = require('.')
 
-module.exports = () => (req, res, next) => {
-  res.vary('Accept')
-  if (req.accepts([ 'json', 'html' ]) !== 'html') return next()
-  restc
-    .then(html => res.end(html))
-    .catch(error => {
-      console.error('[restc]', 'an error occurred when acquiring restc:', error.message)
-      next()
-    })
+module.exports = options => (req, res, next) => {
+  serve(options)(req, res) || next()
 }

lib/index.js

@@ -0,0 +1,27 @@
+'use strict'
+
+const fs = require('fs')
+const path = require('path')
+
+const content = fs.readFileSync(path.join(__dirname, '../faas/index.html'), 'utf-8')
+
+module.exports = options => (req, res) => {
+  // set vary header for every response
+  res.setHeader('Vary', 'Accept, Origin')
+
+  // return if it is a cross-origin request
+  if ('origin' in req.headers) {
+    return false
+  }
+
+  // return if the client does not prefer text/html
+  let accept = req.headers.accept || ''
+  if (!/^text\/html(?:,|$)/.test(accept)) {
+    return false
+  }
+
+  // serve restc
+  res.send(content)
+
+  return true
+}

lib/koa.js

@@ -1,14 +1,10 @@
 'use strict'
 
-const restc = require('./restc')
+const serve = require('.')
+const response = require('./utils/response')
 
-module.exports = () => function * (next) {
-  this.set('Vary', 'Accept')
-  if (this.accepts([ 'json', 'html' ]) !== 'html') return yield next
-  try {
-    this.body = yield restc
-  } catch (error) {
-    console.error('[restc]', 'an error occurred when acquiring restc:', error.message)
+module.exports = options => function * (next) {
+  if (!serve(options)(this.request, response.fromKoaContext(this))) {
     yield next
   }
 }

lib/koa2.js

@@ -1,16 +1,10 @@
 'use strict'
 
-const restc = require('./restc')
+const serve = require('.')
+const response = require('./utils/response')
 
-module.exports = () => (ctx, next) => {
-  ctx.set('Vary', 'Accept')
-  if (ctx.accepts([ 'json', 'html' ]) !== 'html') return next()
-  return restc
-    .then(html => {
-      ctx.body = html
-    })
-    .catch(error => {
-      console.error('[restc]', 'an error occurred when acquiring restc:', error.message)
-      return next()
-    })
+module.exports = options => (ctx, next) => {
+  if (!serve(options)(ctx.request, response.fromKoaContext(ctx))) {
+    return next()
+  }
 }

lib/utils/response.js

@@ -0,0 +1,16 @@
+'use strict'
+
+// patch Koa responses
+exports.fromKoaContext = ctx => Object.create(ctx.response, {
+  send: {
+    value: payload => {
+      ctx.body = payload
+    }
+  },
+
+  setHeader: {
+    value: (k, v) => {
+      ctx.set(k, v)
+    }
+  }
+})