niterim state for 2.0 development

.eslintrc

@@ -1,42 +1,54 @@
 {
-    "env": {
-        "node": true,
-        "es6": true
-    },
+  "parserOptions": {
+    "ecmaVersion": 6,
+    "sourceType": "module"
+  },
 
-    "extends": "eslint:recommended",
+  "globals": {
+    "app": true,
+    "fetch": true
+  },
 
-    "rules": {
-        "no-cond-assign": 0,
-        "no-constant-condition": 0,
-        "no-empty": 0,
-        "no-fallthrough": 0,
-        "no-unused-vars": 1,
-        "no-console": 1,
+  "env": {
+    "node": true,
+    "es6": true
+  },
 
-        "semi": 2,
-        "curly": 2,
-        "consistent-this": [2, "self"],
-        "indent": [ 2, 4, { "SwitchCase": 1 } ],
-        "linebreak-style": [2, "unix"],
-        "no-nested-ternary": 2,
+  "extends": "eslint:recommended",
 
-        "new-parens": 2,
-        "no-dupe-class-members": 2,
-        "require-yield": 2,
-        "arrow-spacing": 1,
-        "no-var": 2,
+  "rules": {
+    "array-bracket-spacing": [2, "never"],
+    "block-scoped-var": 2,
+    "brace-style": [2, "1tbs"],
+    "computed-property-spacing": [2, "never"],
+    "curly": 2,
+    "eol-last": 2,
+    "eqeqeq": [2, "smart"],
+    "max-depth": [1, 3],
+    "new-cap": 1,
+    "no-extend-native": 2,
+    "no-mixed-spaces-and-tabs": 2,
+    "no-trailing-spaces": 1,
+    "no-unused-vars": 1,
+    "no-use-before-define": [2, "nofunc"],
+    "object-curly-spacing": [2, "never"],
+    "quotes": [1, "single", "avoid-escape"],
+    "semi": [2, "always"],
+    "keyword-spacing": [2, {"before": true, "after": true}],
+    "space-unary-ops": 2,
+    "no-console": [1, { allow: ["info", "warn", "error"] }],
 
-        "no-multi-spaces": 1,
-        "space-return-throw-case": 0,
-        "space-infix-ops": [1, {"int32Hint": false}],
-        "brace-style": 1,
-        "space-before-blocks": 1,
-        "operator-linebreak": [1, "before"],
-        "no-unneeded-ternary": 1,
-        "no-lonely-if": 1,
-        "key-spacing": 1,
-        "quotes": [1, "double", "avoid-escape"],
-        "no-trailing-spaces": [1, { "skipBlankLines": true }]
-    }
+    "max-len": [1, 120],
+    "max-statements": [1, 50],
+
+    "consistent-this": [2, "self"],
+    "no-var": 2,
+    "no-dupe-class-members": 2,
+    "operator-linebreak": [1, "before"],
+    "no-unneeded-ternary": [1, {"defaultAssignment": false}],
+    "no-lonely-if": 1,
+    "linebreak-style": [2, "unix"],
+    "no-nested-ternary": 2,
+    "require-yield": 2
+  }
 }

advanced-example.js

@@ -1,45 +1,40 @@
-"use strict";
+'use strict';
 
-const express = require("express");
+const express = require('express');
 const app = express();
-const promBundle = require("express-prom-bundle");
+const promBundle = require('express-prom-bundle');
 
 const bundle = promBundle({
-    prefix: "demo_app:something:",
-    blacklist: [/up/],
-    buckets: [0.1, 0.4, 0.7],
-    includeMethod: true,
-    includePath: true,
-    keepDefaultMetrics: false
+  prefix: 'demo_app:something:',
+  blacklist: [/up/],
+  buckets: [0.1, 0.4, 0.7],
+  includeMethod: true,
+  includePath: true
 });
 
 app.use(bundle);
 
 // native prom-client metric (no prefix)
-const c1 = new bundle.promClient.Counter("c1", "c1 help");
+const c1 = new bundle.promClient.Counter('c1', 'c1 help');
 c1.inc(10);
 
-// create metric using factory (w/ prefix)
-const c2 = bundle.factory.newCounter("c2", "c2 help");
-c2.inc(20);
-
-app.get("/foo/:id", (req, res) => {
-    setTimeout(() => {
-        res.send("foo response\n");
-    }, 500);
+app.get('/foo/:id', (req, res) => {
+  setTimeout(() => {
+    res.send('foo response\n');
+  }, 500);
 });
-app.delete("/foo/:id", (req, res) => {
-    setTimeout(() => {
-        res.send("foo deleted\n");
-    }, 300);
+app.delete('/foo/:id', (req, res) => {
+  setTimeout(() => {
+    res.send('foo deleted\n');
+  }, 300);
 });
-app.get("/bar", (req, res) => res.send("bar response\n"));
+app.get('/bar', (req, res) => res.send('bar response\n'));
 
 app.listen(3000, () => console.info(  // eslint-disable-line
-  "listening on 3000\n"
-  + "test in shell console\n\n"
-  + "curl localhost:3000/foo/1234\n"
-  + "curl -X DELETE localhost:3000/foo/5432\n"
-  + "curl localhost:3000/bar\n"
-  + "curl localhost:3000/metrics\n"
+  'listening on 3000\n'
+  + 'test in shell console\n\n'
+  + 'curl localhost:3000/foo/1234\n'
+  + 'curl -X DELETE localhost:3000/foo/5432\n'
+  + 'curl localhost:3000/bar\n'
+  + 'curl localhost:3000/metrics\n'
 ));

package.json

@@ -16,7 +16,7 @@
   "license": "MIT",
   "dependencies": {
     "on-finished": "^2.3.0",
-    "prom-client": "^6.2.0",
+    "prom-client": "^6.3.0",
     "url-value-parser": "^1.0.0"
   },
   "devDependencies": {

spec/PromFactorySpec.js

@@ -1,65 +0,0 @@
-"use strict";
-/* eslint-env jasmine */
-const PromFactory = require("../src/PromFactory");
-
-describe("PromFactory", () => {
-    let factory;
-    beforeEach(() => {
-        factory = new PromFactory();
-    });
-    it("creates Counter", () => {
-        const metric = factory.newCounter(
-            "test1",
-            "help for test1",
-            ["label1", "label2"]
-        );
-        expect(metric.name).toBe("test1");
-        expect(metric.help).toBe("help for test1");
-        expect(metric.labelNames).toEqual(["label1", "label2"]);
-    });
-    it("creates Gauge", () => {
-        const metric = factory.newGauge(
-            "test2",
-            "help for test2",
-            ["label1", "label2"]
-        );
-        expect(metric.name).toBe("test2");
-        expect(metric.help).toBe("help for test2");
-        expect(metric.labelNames).toEqual(["label1", "label2"]);
-    });
-    it("creates Histogram with labels", () => {
-        const metric = factory.newHistogram(
-            "test3",
-            "help for test3",
-            ["label1", "label2"],
-            {buckets: [1, 2, 3]}
-        );
-        expect(metric.name).toBe("test3");
-        expect(metric.help).toBe("help for test3");
-        expect(metric.labelNames).toEqual(["label1", "label2"]);
-        expect(metric.bucketValues).toEqual({"1": 0, "2": 0, "3": 0});
-    });
-    it("creates Summary without labels", () => {
-        const metric = factory.newSummary(
-            "test4",
-            "help for test4",
-            {percentiles: [0.1, 0.5]}
-        );
-        expect(metric.name).toBe("test4");
-        expect(metric.help).toBe("help for test4");
-        expect(metric.percentiles).toEqual([0.1, 0.5]);
-    });
-    it("when regsitered with same name, just return old instance", () => {
-        const metric1 = factory.newSummary(
-            "test4",
-            "help for test4",
-            {percentiles: [0.1, 0.5]}
-        );
-        const metric2 = factory.newSummary(
-            "test4",
-            "help for test4",
-            {percentiles: [0.1, 0.5]}
-        );
-        expect(metric1).toBe(metric2);
-    });
-});

spec/index.spec.js

@@ -0,0 +1,213 @@
+'use strict';
+/* eslint-env jasmine */
+
+const express = require('express');
+const supertest = require('supertest');
+const bundle = require('../');
+const koa = require('koa');
+const c2k = require('koa-connect');
+const supertestKoa = require('supertest-koa-agent');
+const promClient = require('prom-client');
+
+// had to reinvent, because getSingleMetric() is still not in npm
+function myGetSingleMetric(name) {
+  let returnMetric;
+  promClient.register.getMetricsAsJSON().forEach(metric => {
+    if (metric.name === name) {
+      returnMetric = metric;
+    }
+  });
+  return returnMetric;
+}
+
+describe('index', () => {
+  beforeEach(() => {
+    promClient.register.clear();
+  });
+
+  it('metrics returns up=1', done => {
+    const app = express();
+    const bundled = bundle({
+      whitelist: ['up']
+    });
+    app.use(bundled);
+    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(/up\s1/);
+          done();
+        });
+    });
+  });
+
+  it('metrics should be attached to /metrics by default', done => {
+    const app = express();
+    const bundled = bundle({
+      prefix: 'hello:',
+      whitelist: ['up']
+    });
+    app.use(bundled);
+
+    const agent = supertest(app);
+    agent.get('/metrics')
+      .end((err, res) => {
+        expect(res.status).toBe(200);
+        done();
+      });
+  });
+
+  it('metrics can be attached to /metrics programatically', done => {
+    const app = express();
+    const bundled = bundle({
+      autoregister: false
+    });
+    app.use(bundled.metricsMiddleware);
+    app.use(bundled);
+
+    app.use('/test', (req, res) => res.send('it worked'));
+
+    const agent = supertest(app);
+    agent.get('/metrics')
+      .end((err, res) => {
+        expect(res.status).toBe(200);
+        done();
+      });
+  });
+
+  it('metrics can be filtered using exect match', () => {
+    const instance = bundle({blacklist: ['up']});
+    expect(instance.metrics.up).not.toBeDefined();
+    expect(instance.metrics.http_request_duration_seconds).toBeDefined();
+  });
+  it('metrics can be filtered using regex', () => {
+    const instance = bundle({blacklist: [/http/]});
+    expect(instance.metrics.up).toBeDefined();
+    expect(instance.metrics.http_request_duration_seconds).not.toBeDefined();
+  });
+  it('metrics can be whitelisted', () => {
+    const instance = bundle({whitelist: [/^up$/]});
+    expect(instance.metrics.up).toBeDefined();
+    expect(instance.metrics.nodejs_memory_heap_total_bytes).not.toBeDefined();
+    expect(instance.metrics.http_request_duration_seconds).not.toBeDefined();
+  });
+  it('throws on both white and blacklist', () => {
+    expect(() => {
+      bundle({whitelist: [/up/], blacklist: [/up/]});
+    }).toThrow();
+  });
+  it('returns error 500 on incorrect middleware usage', done => {
+    const app = express();
+    app.use(bundle);
+    supertest(app)
+      .get('/metrics')
+      .end((err, res) => {
+        expect(res.status).toBe(500);
+        done();
+      });
+  });
+  it('http latency gets counted', done => {
+    const app = express();
+    const instance = bundle();
+    app.use(instance);
+    app.use('/test', (req, res) => res.send('it worked'));
+    const agent = supertest(app);
+    agent
+      .get('/test')
+      .end(() => {
+        const metricHashMap = instance.metrics.http_request_duration_seconds.hashMap;
+        expect(metricHashMap['status_code:200']).toBeDefined();
+        const labeled = metricHashMap['status_code:200'];
+        expect(labeled.count).toBe(1);
+
+        agent
+          .get('/metrics')
+          .end((err, res) => {
+            expect(res.status).toBe(200);
+            done();
+          });
+      });
+  });
+  it('filters out the excludeRoutes', done => {
+    const app = express();
+    const instance = bundle({
+      excludeRoutes: ['/test']
+    });
+    app.use(instance);
+    app.use('/test', (req, res) => res.send('it worked'));
+    const agent = supertest(app);
+    agent
+      .get('/test')
+      .end(() => {
+        const metricHashMap = instance.metrics.http_request_duration_seconds.hashMap;
+        expect(metricHashMap['status_code:200']).not.toBeDefined();
+
+        agent
+          .get('/metrics')
+          .end((err, res) => {
+            expect(res.status).toBe(200);
+            done();
+          });
+      });
+  });
+
+  it('removes metrics on start with ', () => {
+    new promClient.Counter('foo', 'bar');
+    expect(promClient.getSingleMetric('foo')).toBeDefined();
+    bundle();
+    expect(promClient.getSingleMetric('foo')).not.toBeDefined();
+  });
+
+  it('tolerates includePath, includeMethod and keepDefaultMetrics', done => {
+    const app = express();
+    const instance = bundle({
+      includePath: true,
+      includeMethod: true,
+      keepDefaultMetrics: true
+    });
+    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);
+            done();
+          });
+      });
+  });
+
+  it('Koa: metrics returns up=1', done => {
+    const app = koa();
+    const bundled = bundle({
+      prefix: 'hello:',
+      whitelist: ['up']
+    });
+    app.use(c2k(bundled));
+
+    app.use(function*(next) {
+      if (this.path !== 'test') {
+        return yield next;
+      }
+      this.body = 'it worked';
+    });
+
+    const agent = supertestKoa(app);
+    agent.get('/test').end(() => {
+      agent
+        .get('/metrics')
+        .end((err, res) => {
+          expect(res.status).toBe(200);
+          expect(res.text).toMatch(/hello:up\s1/);
+          done();
+        });
+    });
+  });
+});

spec/indexSpec.js

@@ -1,231 +0,0 @@
-"use strict";
-/* eslint-env jasmine */
-
-const express = require("express");
-const supertest = require("supertest");
-const bundle = require("../");
-const koa = require("koa");
-const c2k = require("koa-connect");
-const supertestKoa = require("supertest-koa-agent");
-const promClient = require("prom-client");
-
-// had to reinvent, because getSingleMetric() is still not in npm
-function myGetSingleMetric(name) {
-    let returnMetric;
-    promClient.register.getMetricsAsJSON().forEach(metric => {
-        if (metric.name === name) {
-            returnMetric = metric;
-        }
-    });
-    return returnMetric;
-}
-
-describe("index", () => {
-    beforeEach(() => {
-        promClient.register.clear();
-    });
-
-    it("metrics returns up=1", done => {
-        const app = express();
-        const bundled = bundle({
-            prefix: "hello:",
-            whitelist: ["up"]
-        });
-        app.use(bundled);
-
-        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(/hello:up\s1/);
-                    done();
-                });
-        });
-    });
-
-    it("metrics should be attached to /metrics by default", done => {
-        const app = express();
-        const bundled = bundle({
-            prefix: "hello:",
-            whitelist: ["up"]
-        });
-        app.use(bundled);
-
-        const agent = supertest(app);
-        agent.get("/metrics")
-            .end((err, res) => {
-                expect(res.status).toBe(200);
-                done();
-            });
-    });
-
-    it("metrics can be attached to /metrics programatically", done => {
-        const app = express();
-        const bundled = bundle({
-            autoregister: false
-        });
-        app.use(bundled.metricsMiddleware);
-        app.use(bundled);
-
-        app.use("/test", (req, res) => res.send("it worked"));
-
-        const agent = supertest(app);
-        agent.get("/metrics")
-            .end((err, res) => {
-                expect(res.status).toBe(200);
-                done();
-            });
-    });
-
-    it("metrics can be filtered using exect match", () => {
-        const instance = bundle({blacklist: ["up"]});
-        expect(instance.metrics.up).not.toBeDefined();
-        expect(instance.metrics.nodejs_memory_heap_total_bytes).toBeDefined();
-    });
-    it("metrics can be filtered using regex", () => {
-        const instance = bundle({blacklist: [/memory/]});
-        expect(instance.metrics.up).toBeDefined();
-        expect(instance.metrics.nodejs_memory_heap_total_bytes).not.toBeDefined();
-    });
-    it("metrics can be whitelisted", () => {
-        const instance = bundle({whitelist: [/^up$/]});
-        expect(instance.metrics.up).toBeDefined();
-        expect(instance.metrics.nodejs_memory_heap_total_bytes).not.toBeDefined();
-        expect(instance.metrics.http_request_seconds).not.toBeDefined();
-    });
-    it("throws on both white and blacklist", () => {
-        expect(() => {
-            bundle({whitelist: [/up/], blacklist: [/up/]});
-        }).toThrow();
-    });
-    it("returns error 500 on incorrect middleware usage", done => {
-        const app = express();
-        app.use(bundle);
-        supertest(app)
-            .get("/metrics")
-            .end((err, res) => {
-                expect(res.status).toBe(500);
-                done();
-            });
-    });
-    it("http latency gets counted", done => {
-        const app = express();
-        const instance = bundle();
-        app.use(instance);
-        app.use("/test", (req, res) => res.send("it worked"));
-        const agent = supertest(app);
-        agent
-            .get("/test")
-            .end(() => {
-                const metricHashMap = instance.metrics.http_request_seconds.hashMap;
-                expect(metricHashMap["status_code:200"]).toBeDefined();
-                const labeled = metricHashMap["status_code:200"];
-                expect(labeled.count).toBe(1);
-
-                agent
-                    .get("/metrics")
-                    .end((err, res) => {
-                        expect(res.status).toBe(200);
-                        done();
-                    });
-            });
-    });
-    it("filters out the excludeRoutes", done => {
-        const app = express();
-        const instance = bundle({
-            excludeRoutes: ["/test"]
-        });
-        app.use(instance);
-        app.use("/test", (req, res) => res.send("it worked"));
-        const agent = supertest(app);
-        agent
-            .get("/test")
-            .end(() => {
-                const metricHashMap = instance.metrics.http_request_seconds.hashMap;
-                expect(metricHashMap["status_code:200"]).not.toBeDefined();
-
-                agent
-                    .get("/metrics")
-                    .end((err, res) => {
-                        expect(res.status).toBe(200);
-                        done();
-                    });
-            });
-    });
-
-    describe("initial metrics removal", () => {
-        it("removes unexpected metrics on start with no prefix", () => {
-            new promClient.Counter("foo", "bar");
-            expect(myGetSingleMetric("foo")).toBeDefined();
-            bundle();
-            expect(myGetSingleMetric("foo")).not.toBeDefined();
-        });
-
-        it("removes unexpected metrics on start with a prefix", () => {
-            new promClient.Counter("foo", "bar");
-            expect(myGetSingleMetric("foo")).toBeDefined();
-            bundle({prefix: "some_test_"});
-            expect(myGetSingleMetric("foo")).not.toBeDefined();
-        });
-
-        it("doesnt remove metrics with matched prefix", () => {
-            new promClient.Counter("some_test_foo", "bar");
-            expect(myGetSingleMetric("some_test_foo")).toBeDefined();
-            bundle({prefix: "some_test_"});
-            expect(myGetSingleMetric("some_test_foo")).toBeDefined();
-        });
-    });
-
-    it("tolerates includePath, includeMethod and keepDefaultMetrics", done => {
-        const app = express();
-        const instance = bundle({
-            includePath: true,
-            includeMethod: true,
-            keepDefaultMetrics: true
-        });
-        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);
-                        done();
-                    });
-            });
-    });
-
-    it("Koa: metrics returns up=1", done => {
-        const app = koa();
-        const bundled = bundle({
-            prefix: "hello:",
-            whitelist: ["up"]
-        });
-        app.use(c2k(bundled));
-
-        app.use(function*(next) {
-            if (this.path !== "test") {
-                return yield next;
-            }
-            this.body = "it worked";
-        });
-
-        const agent = supertestKoa(app);
-        agent.get("/test").end(() => {
-            agent
-                .get("/metrics")
-                .end((err, res) => {
-                    expect(res.status).toBe(200);
-                    expect(res.text).toMatch(/hello:up\s1/);
-                    done();
-                });
-        });
-    });
-});

spec/normalizePath.spec.js

@@ -0,0 +1,28 @@
+'use strict';
+/* eslint-env jasmine */
+
+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'}))
+      .toBe('/a/#val');
+  });
+});

spec/normalizePathSpec.js

@@ -1,28 +0,0 @@
-"use strict";
-/* eslint-env jasmine */
-
-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"}))
-            .toBe("/a/#val");
-    });
-});

src/PromFactory.js

@@ -1,46 +0,0 @@
-"use strict";
-
-module.exports = class {
-    constructor(opts) {
-        this.opts = opts || {};
-        this.promClient = this.opts.promClient || require("prom-client");
-    }
-
-    makeRealName(name) {
-        return (this.opts.prefix || "") + name;
-    }
-
-    makeMetric(TheClass, args) {
-        // convert pseudo-array
-        const applyParams = Array.prototype.slice.call(args);
-        const name = applyParams[0];
-        const realName = this.makeRealName(name);
-
-        const existing = this.promClient.register.getSingleMetric(realName);
-        if (existing) {
-            return existing;
-        }
-
-        applyParams[0] = realName;
-        applyParams.unshift(null); // add some dummy context for apply
-
-        // call constructor with variable params
-        return new (Function.prototype.bind.apply(TheClass, applyParams)); // eslint-disable-line
-    }
-
-    newCounter() {
-        return this.makeMetric(this.promClient.Counter, arguments);
-    }
-
-    newGauge() {
-        return this.makeMetric(this.promClient.Gauge, arguments);
-    }
-
-    newHistogram() {
-        return this.makeMetric(this.promClient.Histogram, arguments);
-    }
-
-    newSummary() {
-        return this.makeMetric(this.promClient.Summary, arguments);
-    }
-};

src/index.js

@@ -1,164 +1,145 @@
-"use strict";
-
-const PromFactory = require("./PromFactory");
-const onFinished = require("on-finished");
-const url = require("url");
-const promClient = require("prom-client");
-const normalizePath = require("./normalizePath");
+'use strict';
+const onFinished = require('on-finished');
+const url = require('url');
+const promClient = require('prom-client');
+const normalizePath = require('./normalizePath');
 
 function matchVsRegExps(element, regexps) {
-    for (let regexp of regexps) {
-        if (regexp instanceof RegExp) {
-            if (element.match(regexp)) {
-                return true;
-            }
-        } else if (element == regexp) {
-            return true;
-        }
+  for (let regexp of regexps) {
+    if (regexp instanceof RegExp) {
+      if (element.match(regexp)) {
+        return true;
+      }
+    } else if (element === regexp) {
+      return true;
     }
-    return false;
+  }
+  return false;
 }
 
 function filterArrayByRegExps(array, regexps) {
-    return array.filter(element => {
-        return matchVsRegExps(element, regexps);
-    });
+  return array.filter(element => {
+    return matchVsRegExps(element, regexps);
+  });
 }
 
 function prepareMetricNames(opts, metricTemplates) {
-    const names = Object.keys(metricTemplates);
-    if (opts.whitelist) {
-        if (opts.blacklist) {
-            throw new Error("you cannot have whitelist and blacklist at the same time");
-        }
-        return filterArrayByRegExps(names, opts.whitelist);
-    }
+  const names = Object.keys(metricTemplates);
+  if (opts.whitelist) {
     if (opts.blacklist) {
-        const blacklisted = filterArrayByRegExps(names, opts.blacklist);
-        return names.filter(name => blacklisted.indexOf(name) === -1);
+      throw new Error('you cannot have whitelist and blacklist at the same time');
     }
-    return names;
+    return filterArrayByRegExps(names, opts.whitelist);
+  }
+  if (opts.blacklist) {
+    const blacklisted = filterArrayByRegExps(names, opts.blacklist);
+    return names.filter(name => blacklisted.indexOf(name) === -1);
+  }
+  return names;
 }
 
 function main(opts) {
-    opts = Object.assign({ autoregister: true }, opts || {} );
-    if (arguments[2] && arguments[1] && arguments[1].send) {
-        arguments[1].status(500)
-            .send("<h1>500 Error</h1>\n"
-                + "<p>Unexpected 3rd param in express-prom-bundle.\n"
-                + "<p>Did you just put express-prom-bundle into app.use "
-                + "without calling it as a function first?");
-        return;
+  opts = Object.assign({autoregister: true}, opts || {});
+  if (arguments[2] && arguments[1] && arguments[1].send) {
+    arguments[1].status(500)
+      .send('<h1>500 Error</h1>\n'
+        + '<p>Unexpected 3rd param in express-prom-bundle.\n'
+        + '<p>Did you just put express-prom-bundle into app.use '
+        + 'without calling it as a function first?');
+    return;
+  }
+
+  // this is a really messy hack but needed for compatibility with v1
+  // will be completely removed in v2
+  if (opts.keepDefaultMetrics === false) {
+    const metrics = promClient.register.getMetricsAsJSON();
+    clearInterval(promClient.defaultMetrics());
+    metrics.forEach(metric => {
+      if (!opts.prefix || metric.name.substr(0, opts.prefix.length) !== opts.prefix) {
+        promClient.register.removeSingleMetric(metric.name);
+      }
+    });
+  }
+
+  const httpMtricName = opts.httpDurationMetricName || 'http_request_duration_seconds';
+
+  const metricTemplates = {
+    'up': () => new promClient.Gauge(
+      'up',
+      '1 = up, 0 = not up'
+    ),
+    'http_request_seconds': () => {
+      const labels = ['status_code'];
+      if (opts.includeMethod) {
+        labels.push('method');
+      }
+      if (opts.includePath) {
+        labels.push('path');
+      }
+      const metric = new promClient.Histogram(
+        httpMtricName,
+        'duration histogram of http responses labeled with: ' + labels.join(', '),
+        labels,
+        {
+          buckets: opts.buckets || [0.003, 0.03, 0.1, 0.3, 1.5, 10]
+        }
+      );
+      return metric;
+    }
+  };
+
+  const metrics = {};
+  const names = prepareMetricNames(opts, metricTemplates);
+
+  for (let name of names) {
+    metrics[name] = metricTemplates[name]();
+  }
+
+  if (metrics.up) {
+    metrics.up.set(1);
+  }
+
+  const metricsMiddleware = function(req,res) {
+    res.writeHead(200, {'Content-Type': 'text/plain'});
+    res.end(promClient.register.metrics());
+  };
+
+  const middleware = function (req, res, next) {
+
+    const path = req.path || url.parse(req.url).pathname;
+    let labels;
+
+    if (opts.autoregister && path === '/metrics') {
+      return metricsMiddleware(req,res);
     }
 
-    // this is a really messy hack but needed for compatibility with v1
-    // will be completely removed in v2
-    if (!opts.keepDefaultMetrics) {
-        const metrics = promClient.register.getMetricsAsJSON();
-        clearInterval(promClient.defaultMetrics());
-        metrics.forEach(metric => {
-            if (!opts.prefix || metric.name.substr(0, opts.prefix.length) != opts.prefix) {
-                promClient.register.removeSingleMetric(metric.name);
-            }
-        });
+    if (opts.excludeRoutes && matchVsRegExps(path, opts.excludeRoutes)) {
+      return next();
     }
 
-    const factory = new PromFactory(opts);
-
-    const metricTemplates = {
-        "up": () => factory.newGauge(
-            "up",
-            "1 = up, 0 = not up"
-        ),
-        "nodejs_memory_heap_total_bytes": () => factory.newGauge(
-            "nodejs_memory_heap_total_bytes",
-            "value of process.memoryUsage().heapTotal"
-        ),
-        "nodejs_memory_heap_used_bytes": () => factory.newGauge(
-            "nodejs_memory_heap_used_bytes",
-            "value of process.memoryUsage().heapUsed"
-        ),
-        "http_request_seconds": () => {
-            const labels = ["status_code"];
-            if (opts.includeMethod) {
-                labels.push("method");
-            }
-            if (opts.includePath) {
-                labels.push("path");
-            }
-            const metric = factory.newHistogram(
-                "http_request_seconds",
-                "number of http responses labeled with status code",
-                labels,
-                {
-                    buckets: opts.buckets || [0.003, 0.03, 0.1, 0.3, 1.5, 10]
-                }
-            );
-            return metric;
+    if (metrics[httpMtricName]) {
+      labels = {'status_code': 0};
+      let timer = metrics[httpMtricName].startTimer(labels);
+      onFinished(res, () => {
+        labels.status_code = res.statusCode;
+        if (opts.includeMethod) {
+          labels.method = req.method;
         }
-    };
-
-    const metrics = {};
-    const names = prepareMetricNames(opts, metricTemplates);
-
-    for (let name of names) {
-        metrics[name] = metricTemplates[name]();
+        if (opts.includePath) {
+          labels.path = normalizePath(req, opts);
+        }
+        timer();
+      });
     }
 
-    if (metrics.up) {
-        metrics.up.set(1);
-    }
+    next();
+  };
 
-    const metricsMiddleware = function(req,res) {
-        let memoryUsage = process.memoryUsage();
-        if (metrics["nodejs_memory_heap_total_bytes"]) {
-            metrics["nodejs_memory_heap_total_bytes"].set(memoryUsage.heapTotal);
-        }
-        if (metrics["nodejs_memory_heap_used_bytes"]) {
-            metrics["nodejs_memory_heap_used_bytes"].set(memoryUsage.heapUsed);
-        }
-
-        res.writeHead(200, {"Content-Type": "text/plain"});
-        res.end(factory.promClient.register.metrics());
-    };
-
-    const middleware = function (req, res, next) {
-
-        const path = req.path || url.parse(req.url).pathname;
-        let labels;
-
-        if (opts.autoregister && path == "/metrics") {
-            return metricsMiddleware(req,res);
-        }
-
-        if (opts.excludeRoutes && matchVsRegExps(path, opts.excludeRoutes)) {
-            return next();
-        }
-
-        if (metrics["http_request_seconds"]) {
-            labels = {"status_code": 0};
-            let timer = metrics["http_request_seconds"].startTimer(labels);
-            onFinished(res, () => {
-                labels.status_code = res.statusCode;
-                if (opts.includeMethod) {
-                    labels.method = req.method;
-                }
-                if (opts.includePath) {
-                    labels.path = normalizePath(req, opts);
-                }
-                timer();
-            });
-        }
-
-        next();
-    };
-
-    middleware.factory = factory;
-    middleware.metricTemplates = metricTemplates;
-    middleware.metrics = metrics;
-    middleware.promClient = factory.promClient;
-    middleware.metricsMiddleware = metricsMiddleware;
-    return middleware;
+  middleware.metricTemplates = metricTemplates;
+  middleware.metrics = metrics;
+  middleware.promClient = promClient;
+  middleware.metricsMiddleware = metricsMiddleware;
+  return middleware;
 }
 
 main.promClient = promClient;

src/normalizePath.js

@@ -1,26 +1,27 @@
-"use strict";
+'use strict';
 
-const UrlValueParser = require("url-value-parser");
-const url = require("url");
+const UrlValueParser = require('url-value-parser');
+const url = require('url');
 let urlValueParser;
 
 module.exports = function(req, opts) {
-    opts = opts || {};
+  opts = opts || {};
 
-    // 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).pathname;
+  // 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).pathname;
 
-    if (opts.normalizePath !== undefined && !opts.normalizePath) {
-        return path;
-    }
-    if (typeof opts.normalizePath === "function") {
-        return opts.normalizePath(req, opts);
-    }
+  if (opts.normalizePath !== undefined && !opts.normalizePath) {
+    return path;
+  }
+  if (typeof opts.normalizePath === 'function') {
+    return opts.normalizePath(req, opts);
+  }
 
-    if (!urlValueParser) {
-        urlValueParser = new UrlValueParser();
-    }
-    return urlValueParser.replacePathValues(path);
+  if (!urlValueParser) {
+    urlValueParser = new UrlValueParser();
+  }
+  return urlValueParser.replacePathValues(path);
 };
+