adding test + fix spelling mistake

Author: hsingh6764

lib/express.js

@@ -1,25 +1,25 @@
 const metrics = require('./metrics')
 
-function middleware (request, response, done) {
+function middleware(request, response, done) {
   var start = process.hrtime()
 
-  response.on('finish', function () {
+  response.on('finish', function() {
     metrics.observe(request.method, request.path, response.statusCode, start)
   })
 
   return done()
 };
 
-function instrument (server, options) {
+function instrument(server, options) {
   server.use(middleware)
-  let mertricsEndpointServer = options.metricsServer || server;
-  mertricsEndpointServer.get(options.url, (req, res) => {
+  let metricsEndpointServer = options.metricsServer || server;
+  metricsEndpointServer.get(options.url, (req, res) => {
     res.header('content-type', 'text/plain; charset=utf-8')
     return res.send(metrics.summary())
   })
 }
 
-function instrumentable (server) {
+function instrumentable(server) {
   return server && server.defaultConfiguration && server.use
 }
 

lib/http.js

@@ -1,7 +1,7 @@
 const defaults = require('./defaults')
 const metrics = require('./metrics')
 
-function sendMetrics (request, response) {
+function sendMetrics(request, response) {
   response.writeHead(200, {
     'Content-Type': 'text/plain; charset=utf-8'
   })
@@ -10,16 +10,16 @@ function sendMetrics (request, response) {
   response.end()
 }
 
-function observeMetrics (request, response) {
+function observeMetrics(request, response) {
   var start = process.hrtime()
   response.on('finish', () => {
     metrics.observe(request.method, request.url, response.statusCode, start)
   })
 }
 
-function instrument (server, options) {
-  let mertricsEndpointServer = options.metricsServer || server;
-  mertricsEndpointServer.on('request', (request, response) => {
+function instrument(server, options) {
+  let metricsEndpointServer = options.metricsServer || server;
+  metricsEndpointServer.on('request', (request, response) => {
     if (request.url === options.url) {
       sendMetrics(request, response)
     } else {
@@ -28,7 +28,7 @@ function instrument (server, options) {
   })
 }
 
-function instrumentable (server) {
+function instrumentable(server) {
   return server
 }
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "epimetheus",
-  "version": "1.0.56",
+  "version": "0.0.1",
   "description": "node middleware to automatically instrument node applications for consumption by prometheus",
   "main": "index.js",
   "scripts": {

test/assert-expectations.js

@@ -1,7 +1,7 @@
 const request = require('request')
 const should = require('chai').should()
 
-module.exports = function (options) {
+module.exports = function(options) {
   it('should return 200 for /', (done) => {
     request('http://localhost:3000/', (e, r, b) => {
       r.statusCode.should.equal(200)
@@ -17,7 +17,8 @@ module.exports = function (options) {
   })
 
   it('should return 200 for ' + options.url, (done) => {
-    request('http://localhost:3000' + options.url, (e, r, b) => {
+    let metricsPort = options.metricsServer ? 3001 : 3000;
+    request('http://localhost:' + metricsPort + options.url, (e, r, b) => {
       r.statusCode.should.equal(200)
       should.exist(r.headers['content-type'])
       r.headers['content-type'].should.equal('text/plain; charset=utf-8')
@@ -29,4 +30,13 @@ module.exports = function (options) {
       return done(e)
     })
   })
+
+  if (options.metricsServer) {
+    it('should return 404 for /metrics on 3000', (done) => {
+      request('http://localhost:3000/metrics', (e, r, b) => {
+        r.statusCode.should.equal(404)
+        return done(e)
+      });
+    });
+  }
 }

test/express.js

@@ -4,8 +4,10 @@ const epithemeus = require('../index')
 const assertExpectations = require('./assert-expectations')
 const assert = require('chai').assert
 const libExpress = require('../lib/express')
+const request = require('request')
+const should = require('chai').should()
 
-function setup (options) {
+function setup(options) {
   return describe('express ' + options.url, () => {
     before((done) => {
       const app = express()
@@ -16,7 +18,13 @@ function setup (options) {
       app.get('/resource/:id', (req, res) => {
         res.send()
       })
-      this.server = app.listen(3000, done)
+      this.server = app.listen(3000, () => {
+        if (options.metricsServer) {
+          options.metricsServer.listen(3001, done);
+        } else {
+          done()
+        }
+      });
     })
 
     after((done) => {
@@ -32,11 +40,18 @@ setup({
   url: '/xxx'
 })
 
+setup({
+  url: '/metrics',
+  metricsServer: express()
+})
+
 describe('express should check "instrumentablity" properly', () => {
   it('should return true when express conditions are correct', () => {
     // Arrange
     const server = () => {}
-    server.defaultConfiguration = { sample: true }
+    server.defaultConfiguration = {
+      sample: true
+    }
     server.use = () => {}
 
     // Act
@@ -69,7 +84,9 @@ describe('express should check "instrumentablity" properly', () => {
   it('should return false when server does not have a use function', () => {
     // Arrange
     const server = () => {}
-    server.defaultConfiguration = { sample: true }
+    server.defaultConfiguration = {
+      sample: true
+    }
 
     // Act
     const actual = libExpress.instrumentable(server)