Added Firebase connector (#2)

* Added Firebase connector
* Added empty line
* Updated library to 1.1.0 version

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@myplanet/multivariate",
-  "version": "1.0.0",
+  "version": "1.1.0",
   "description": "A Javascript multivariate testing library",
   "repository": {
     "type": "git",

src/Multivariate.js

@@ -105,4 +105,4 @@ class Multivariate {
 Multivariate.IGNORED_IP_ADDRESSES = [];
 Multivariate.ROBOT_REGEX = /$^|trivial|facebook|MetaURI|butterfly|google|amazon|goldfire|sleuth|xenu|msnbot|SiteUptime|Slurp|WordPress|ZIBB|ZyBorg|pingdom|bot|yahoo|slurp|java|fetch|spider|url|crawl|oneriot|abby|commentreader|twiceler/i;
 
-module.exports = Multivariate;
+module.exports = Multivariate;

src/connector/FirebaseConnector.js

@@ -0,0 +1,64 @@
+const Connector = require('./Connector');
+
+class FirebaseConnector extends Connector {
+    constructor(firebaseClient, rootRef) {
+        super();
+        this.firebaseClient = firebaseClient;
+        this.rootRef = rootRef;
+    }
+
+    getReference(key, field) {
+        const path = field ? `${key}/${field}` : `${key}`;
+        return this.firebaseClient.ref(this.rootRef).child(path);
+    }
+
+    async get(type, key, field) {
+        const experimentsStatsRef = this.getReference(key, field);
+        return experimentsStatsRef.once('value')
+            .then(dataSnapshot => {
+                return dataSnapshot.val();
+            });
+    }
+
+    async set(type, key, field, value) {
+        return value
+            ? this.getReference(key).update({ [field]: value })
+            : this.getReference(key, field).remove();
+    }
+
+    async increment(type, key, field, amount = 1) {
+        const experimentsStatsRef = this.getReference(key);
+        const childRef = experimentsStatsRef.child(field);
+        const child = await childRef.once('value');
+        if (child.val) {
+            const currentVal = child.val();
+            return experimentsStatsRef.update({ [field]: currentVal + amount });
+        } else {
+            return this.save(type, key, { [field]: amount });
+        }
+
+    }
+
+    async save(type, key, saveData) {
+        return this.getReference(key).set(saveData);
+    }
+
+    async load(type, key) {
+        const experimentsStatsRef = this.getReference(key);
+        return experimentsStatsRef.once('value')
+            .then(dataSnapshot => {
+                return dataSnapshot.val();
+            });
+    }
+
+    async reset(type, key, ...fields) {
+        const saveData = fields.reduce((res, el) => res[field] = 0, {});
+        return this.getReference(key).set(saveData);
+    }
+
+    async delete(type, key) {
+        return this.getReference(key).remove();
+    }
+}
+
+module.exports = FirebaseConnector;

src/index.js

@@ -1,9 +1,11 @@
 const Multivariate = require('./Multivariate');
 const Connector = require('./connector/Connector');
 const RedisConnector = require('./connector/RedisConnector');
+const FirebaseConnector = require('./connector/FirebaseConnector');
 
 module.exports = {
     Multivariate: Multivariate,
     Connector: Connector,
-    RedisConnector: RedisConnector
+    RedisConnector: RedisConnector,
+    FirebaseConnector: FirebaseConnector
 }