extend unittests, simplify API, update README, use npm5 and package-lock.json, add node7 to travis config

.travis.yml

@@ -1,3 +1,4 @@
 language: node_js
 node_js:
     - "6"
+    - "7"

README.md

@@ -4,27 +4,25 @@
 
 Express middleware with popular prometheus metrics in one bundle. It's also compatible with koa v1 and v2 (see below).
 
-Internally it uses **prom-client**. See: https://github.com/siimon/prom-client
+Internally it uses **prom-client**. See: https://github.com/siimon/prom-client (^9.0.0)
 
 Included metrics:
 
 * `up`: normally is just 1
 * `http_request_duration_seconds`: http latency histogram labeled with `status_code`, `method` and `path`
 
-**Please note version 2.x is NOT backwards compatible with 1.x**
-
 ## Install
 
 ```
 npm install express-prom-bundle
 ```
 
-## Usage
+## Sample uUsage
 
 ```javascript
 const promBundle = require("express-prom-bundle");
-const metricsMiddleware = promBundle({/* options */ });
 const app = require("express")();
+const metricsMiddleware = promBundle({includeMethod: true});
 
 app.use(metricsMiddleware);
 app.use(/* your middleware */);
@@ -44,17 +42,31 @@ See the example below.
 
 ## Options
 
-* **buckets**: buckets used for `http_request_seconds` histogram
-* **includeMethod**: include HTTP method (GET, PUT, ...) as a label to `http_request_duration_seconds`
-* **includePath**: include URL path as a label (see below)
-* **normalizePath**: boolean or `function(req)` - path normalization for `includePath` option
+Which labels to include in `http_request_duration_seconds` metric:
+
+* **includeStatusCode**: HTTP status code (200, 400, 404 etc.), default: **true**
+* **includeMethod**: HTTP method (GET, PUT, ...), default: **false**
+* **includePath**: URL path (see importent details below), default: **false**
+
+Extra transformation callbacks:
+
+* **normalizePath**: `function(req)` generates path values from express `req` (see details below)
+* **formatStatusCode**: `function(res)` producing final status code from express `res` object, e.g. you can combine `200`, `201` and `204` to just `2xx`.
+
+Other options:
+
+* **buckets**: buckets used for `http_request_duration_seconds` histogram
 * **autoregister**: if `/metrics` endpoint should be registered. (Default: **true**)
-* **whitelist**, **blacklist**: array of strings or regexp specifying which metrics to include/exclude
-* **excludeRoutes**: (deprecated) array of strings or regexp specifying which routes should be skipped for `http_request_duration_seconds` metric. It uses `req.originalUrl` as subject when checking. You want normally use express or meddleware features instead of this options.
+
+Deprecated:
+
+* **whitelist**, **blacklist**: array of strings or regexp specifying which metrics to include/exclude (there are only 2 metrics)
+* **excludeRoutes**: array of strings or regexp specifying which routes should be skipped for `http_request_duration_seconds` metric. It uses `req.originalUrl` as subject when checking. You want to use express or meddleware features instead of this option.
 
 ### More details on includePath option
 
-The goal is to have separate latency statistics by URL path, e.g. `/my-app/user/`, `/products/by-category` etc.
+Let's say you want to have  latency statistics by URL path,
+e.g. separate metrics for `/my-app/user/`, `/products/by-category` etc.
 
 Just taking `req.path` as a label value won't work as IDs are often part of the URL,
 like `/user/12352/profile`. So what we actually need is a path template.
@@ -65,8 +77,6 @@ normalized to `/user/#val/profile` and that will become the value for the label.
 You can override this magical behavior and define your own function by
 providing an optional callback using **normalizePath** option.
 You can also replace the default **normalizePath** function globally.
-This is handy if the rest of the middleware is done elsewhere
-e.g. via `kraken.js meddleware`.
 
 ```javascript
 app.use(promBundle(/* options? */));
@@ -160,7 +170,9 @@ Here is meddleware config sample, which can be used in a standard **kraken.js**
  * **3.0.0**
     * upgrade dependencies, most notably **prom-client** to 9.0.0
     * switch to koa v2 in koa unittest
-    * only node v6 is supported (stop supporting node v4 and v5)
+    * only node v6 or higher is supported (stop supporting node v4 and v5)
+    * switch to npm5 and use package-lock.json
+    * options added: includeStatusCode, formatStatusCode
  * **2.1.0**
     * deprecate **excludeRoutes**, use **req.originalUrl** instead of **req.path**
  * **2.0.0**

spec/index.spec.js

@@ -169,7 +169,7 @@ describe('index', () => {
       });
   });
 
-  it('normalizePath can be replaced', done => {
+  it('normalizePath can be replaced gloablly', done => {
     const app = express();
     const original = bundle.normalizePath;
     bundle.normalizePath = () => 'dummy';
@@ -193,6 +193,70 @@ describe('index', () => {
       });
   });
 
+  it('normalizePath can be overridden', done => {
+    const app = express();
+    const instance = bundle({
+      includePath: true,
+      normalizePath: req => req.originalUrl + '-suffixed'
+    });
+    app.use(instance);
+    app.use('/test', (req, res) => res.send('it worked'));
+    const agent = supertest(app);
+    agent
+      .get('/test')
+      .end(() => {
+        agent
+          .get('/metrics')
+          .end((err, res) => {
+            expect(res.status).toBe(200);
+            expect(res.text).toMatch(/"\/test-suffixed"/m);
+            done();
+          });
+      });
+  });
+
+  it('formatStatusCode can be overridden', done => {
+    const app = express();
+    const instance = bundle({
+      formatStatusCode: () => 555
+    });
+    app.use(instance);
+    app.use('/test', (req, res) => res.send('it worked'));
+    const agent = supertest(app);
+    agent
+      .get('/test')
+      .end(() => {
+        agent
+          .get('/metrics')
+          .end((err, res) => {
+            expect(res.status).toBe(200);
+            expect(res.text).toMatch(/555/);
+            done();
+          });
+      });
+  });
+
+  it('includeStatusCode=false removes status_code label from metrics', done => {
+    const app = express();
+    const instance = bundle({
+      includeStatusCode: false
+    });
+    app.use(instance);
+    app.use('/test', (req, res) => res.send('it worked'));
+    const agent = supertest(app);
+    agent
+      .get('/test')
+      .end(() => {
+        agent
+          .get('/metrics')
+          .end((err, res) => {
+            expect(res.status).toBe(200);
+            expect(res.text).not.toMatch(/200/);
+            done();
+          });
+      });
+  });
+
   it('Koa: metrics returns up=1', done => {
     const app = new Koa();
     const bundled = bundle({

spec/normalizePath.spec.js

@@ -4,25 +4,8 @@
 const normalizePath = require('../src/normalizePath');
 
 describe('normalizePath', () => {
-  it('returns original if disabled in opts', () => {
-    expect(
-     normalizePath({originalUrl: '/a/12345'}, {normalizePath: false})
-    ).toBe('/a/12345');
-  });
-
-  it('returns run callback if configured', () => {
-    expect(
-      normalizePath(
-        {originalUrl: '/a/12345'},
-        {
-          normalizePath: req => req.originalUrl + '-ok'
-        }
-      )
-    ).toBe('/a/12345-ok');
-  });
-
   it('uses UrlValueParser by default', () => {
-    expect(normalizePath({originalUrl: '/a/12345'}))
+    expect(normalizePath({url: '/a/12345'}))
       .toBe('/a/#val');
   });
 });

spec/normalizeStatusCode.spec.js

@@ -4,20 +4,9 @@
 const normalizeStatusCode = require('../src/normalizeStatusCode');
 
 describe('normalizeStatusCode', () => {
-  it('returns original if disabled in opts', () => {
-    expect(
-     normalizeStatusCode({status_code: 404}, {normalizeStatusCode: false})
-   ).toBe(404);
-  });
-
   it('returns run callback if configured', () => {
     expect(
-      normalizeStatusCode(
-        {status_code: 500},
-        {
-          formatStatusCode: res => String(res.status_code).slice(0, -2) + 'xx'
-        }
-      )
-    ).toBe('5xx');
+      normalizeStatusCode({status_code: 500})
+    ).toBe(500);
   });
 });

src/index.js

@@ -39,7 +39,15 @@ function prepareMetricNames(opts, metricTemplates) {
 }
 
 function main(opts) {
-  opts = Object.assign({autoregister: true}, opts);
+  opts = Object.assign(
+    {
+      autoregister: true,
+      includeStatusCode: true,
+      normalizePath: main.normalizePath,
+      formatStatusCode: main.normalizeStatusCode
+    },
+    opts
+  );
   if (arguments[2] && arguments[1] && arguments[1].send) {
     arguments[1].status(500)
       .send('<h1>500 Error</h1>\n'
@@ -114,20 +122,17 @@ function main(opts) {
     }
 
     if (metrics[httpMtricName]) {
-      labels = {'status_code': 0};
+      labels = {};
       let timer = metrics[httpMtricName].startTimer(labels);
       onFinished(res, () => {
-        if (opts.normalizeStatusCode) {
-          labels.status_code = main.normalizeStatusCode(res, opts);
-        } else {
-          labels.status_code = res.statusCode;
+        if (opts.includeStatusCode) {
+          labels.status_code = opts.formatStatusCode(res, opts);
         }
-
         if (opts.includeMethod) {
           labels.method = req.method;
         }
         if (opts.includePath) {
-          labels.path = main.normalizePath(req, opts);
+          labels.path = opts.normalizePath(req, opts);
         }
         timer();
       });

src/normalizePath.js

@@ -4,21 +4,12 @@ const UrlValueParser = require('url-value-parser');
 const url = require('url');
 let urlValueParser;
 
-module.exports = function(req, opts) {
-  opts = opts || {};
-
+module.exports = function(req) {
   // originalUrl is taken, because url and path can be changed
   // by middlewares such as 'router'. Note: this function is called onFinish
   /// i.e. always in the tail of the middleware chain
   const path = url.parse(req.originalUrl || req.url).pathname;
 
-  if (opts.normalizePath !== undefined && !opts.normalizePath) {
-    return path;
-  }
-  if (typeof opts.normalizePath === 'function') {
-    return opts.normalizePath(req, opts);
-  }
-
   if (!urlValueParser) {
     urlValueParser = new UrlValueParser();
   }

src/normalizeStatusCode.js

@@ -1,11 +1,5 @@
 'use strict';
 
-module.exports = function(res, opts) {
-  opts = opts || {};
-
-  if (typeof opts.formatStatusCode === 'function') {
-    return opts.formatStatusCode(res, opts);
-  }
-
-  return res.status_code;
+module.exports = function(res) {
+  return res.status_code || res.statusCode;
 };