rewrite unit tests

app.test.js

@@ -0,0 +1,16 @@
+const fs = require('fs')
+const path = require('path')
+
+let app
+before(() => {
+  app = require('./app.js')
+  global.host = 'http://localhost:' + app.server.address().port
+})
+after((done) => {
+  app.server.close(done)
+})
+
+fs.readdirSync(path.resolve(__dirname, 'test'))
+.forEach(file => {
+    require('./test/' + file)
+})