From 88a74e17725e54a370dd6626fb4fedd518ffece4 Mon Sep 17 00:00:00 2001
From: Gergely Nemeth <mail@nemethgergely.com>
Date: Thu, 6 Aug 2015 14:12:54 +0200
Subject: [PATCH] feat(ignoreHeaders): add ignoreHeaders to the config

---
 README.md                               |  4 +++
 lib/index.js                            |  2 +-
 lib/wraps/http.Server.prototype.js      | 16 +++++++++-
 lib/wraps/http.Server.prototype.spec.js | 40 +++++++++++++++++++++++++
 lib/wraps/index.js                      | 12 ++++----
 5 files changed, 66 insertions(+), 8 deletions(-)
 create mode 100644 lib/wraps/http.Server.prototype.spec.js

diff --git a/README.md b/README.md
index 2d9ac47..94e1f45 100644
--- a/README.md
+++ b/README.md
@@ -36,6 +36,10 @@ var config = {};
 
 config.appName = 'Users';
 
+config.ignoreHeaders = {
+  'user-agent': ['007']
+};
+
 config.reporter = require('@risingstack/trace/lib/reporters').trace.create({
  apiKey: '1234',
  appName: config.appName
diff --git a/lib/index.js b/lib/index.js
index 1ef4d7b..cba6e86 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -29,7 +29,7 @@ var config = getConfig();
 
 var collector = new Collector(config);
 
-wraps.instrument(collector);
+wraps.instrument(collector, config);
 
 function setService(config, callback) {
   var reporter = config.reporter;
diff --git a/lib/wraps/http.Server.prototype.js b/lib/wraps/http.Server.prototype.js
index 017d188..ac48041 100644
--- a/lib/wraps/http.Server.prototype.js
+++ b/lib/wraps/http.Server.prototype.js
@@ -3,16 +3,30 @@ var url = require('url');
 var qs = require('qs');
 var uuid = require('node-uuid');
 var microtime = require('microtime');
+var reduce = require('lodash/collection/reduce');
 
 var getNamespace = require('continuation-local-storage').getNamespace;
 
 var Collector = require('../collector');
 
-function wrapListener(listener, collector) {
+function wrapListener(listener, collector, config) {
+
+  var ignoreHeaders = config.ignoreHeaders;
 
   return function (request, response) {
     var headers = request.headers;
 
+    var skipped = reduce(ignoreHeaders, function (found, value, key) {
+      if (headers[key] && value.indexOf(headers[key]) > -1) {
+        found = true;
+      }
+      return found;
+    }, false);
+
+    if (skipped) {
+      return listener.apply(this, arguments);
+    }
+
     var requestUrl = url.parse(request.url);
     var requestQuery = qs.parse(requestUrl.query).requestId;
     var originalWriteHead = response.writeHead;
diff --git a/lib/wraps/http.Server.prototype.spec.js b/lib/wraps/http.Server.prototype.spec.js
new file mode 100644
index 0000000..c697bc1
--- /dev/null
+++ b/lib/wraps/http.Server.prototype.spec.js
@@ -0,0 +1,40 @@
+var expect = require('chai').expect;
+
+var wrapper = require('./http.Server.prototype');
+
+var dummyCollector = {
+  emit: function () {
+  },
+  getService: function () {
+    return 1;
+  }
+};
+
+describe('The http.Server.prototype wrapper module', function () {
+
+  describe('ingoreHeaders option', function () {
+
+    it('skips requests if there is a match', function () {
+
+      var request = {
+        headers: {
+          'user-agent': '007'
+        }
+      };
+
+      var listener = this.sandbox.spy();
+
+      var wrappedListener = wrapper(listener, dummyCollector, {
+        ignoreHeaders: {
+          'user-agent': ['006', '007']
+        }
+      });
+
+      wrappedListener(request);
+
+      expect(listener).to.be.calledWith(request);
+    });
+
+  });
+
+});
diff --git a/lib/wraps/index.js b/lib/wraps/index.js
index b408220..369cae3 100644
--- a/lib/wraps/index.js
+++ b/lib/wraps/index.js
@@ -5,13 +5,13 @@ var stream = require('stream');
 var getNamespace = require('continuation-local-storage').getNamespace;
 var Shimmer = require('./shimmer');
 
-function instrument (collector) {
+function instrument (collector, config) {
   Shimmer.wrap(http.Server.prototype, 'http.Server.prototype', ['on', 'addListener'],
     function (addListener) {
       return function (type, listener) {
         if (type === 'request' && typeof listener === 'function') {
           return addListener.call(this, type,
-            require('./http.Server.prototype.js')(listener, collector));
+            require('./http.Server.prototype.js')(listener, collector, config));
         } else {
           return addListener.apply(this, arguments);
         }
@@ -23,7 +23,7 @@ function instrument (collector) {
       return function (type, listener) {
         if (type === 'request' && typeof listener === 'function') {
           return addListener.call(this, type,
-            require('./http.Server.prototype.js')(listener, collector));
+            require('./http.Server.prototype.js')(listener, collector, config));
         } else {
           return addListener.apply(this, arguments);
         }
@@ -31,15 +31,15 @@ function instrument (collector) {
     });
 
   Shimmer.wrap(http, 'http', 'request', function (original) {
-    return require('./http.request')(original, collector);
+    return require('./http.request')(original, collector, config);
   });
 
   Shimmer.wrap(https, 'https', 'request', function (original) {
-    return require('./http.request')(original, collector);
+    return require('./http.request')(original, collector, config);
   });
 
   Shimmer.wrap(process, 'process', '_fatalException', function (original) {
-    return require('./process._fatalException')(original, collector);
+    return require('./process._fatalException')(original, collector, config);
   });
 
   getNamespace('trace').bindEmitter(stream.prototype);