refactored tests for mocha and tweaked some internals

.gitignore

@@ -1,4 +1,5 @@
 node_modules
 coverage
+artifacts
 .DS_Store
 .DS_Store?

.istanbul.yml

@@ -0,0 +1,11 @@
+reporting:
+    reports:
+        - lcov
+        - text
+        - text-summary
+check:
+    global:
+        statements: 100
+        lines: 100
+        branches: 100
+        functions: 100

.travis.yml

@@ -2,5 +2,7 @@ language: node_js
 node_js:
     - "0.8"
     - "0.10"
-    - "0.11"
-before_install: npm install -g npm
+    - "0.12"
+    - "4"
+    - "6"
+before_install: npm install -g npm@latest-2

lib/cache.js

@@ -14,6 +14,7 @@ var CacheObject = function (conf) {
 
     this.count = 0;
     this.data = {};
+    /*istanbul ignore next*/
     var next = global.setImmediate || process.nextTick;
 
     this.set = function (key, value, callback) {
@@ -68,59 +69,52 @@ var CacheObject = function (conf) {
                     self.count = self.count + 1;
                 }
             }
-
-            if (callback) {
-                callback(null, value);
-            }
+            /* jshint -W030 */
+            callback && callback(null, value);
         });
     };
 
     this.get = function (key, callback) {
         var self = this;
+        if (!callback) {
+            throw('cache.get callback is required.');
+        }
 
+        if (!this.data[key]) {
+            return callback(null, undefined);
+        }
         next(function () {
-            if (self.data[key]) {
-                if (conf.ttl !== 0 && (Date.now() - self.data[key].ts) >= self.ttl) {
-                    if (self.data[key].newer) {
-                        if (self.data[key].older) {
-                            // in the middle of the list
-                            self.data[key].newer.older = self.data[key].older;
-                            self.data[key].older.newer = self.data[key].newer;
-                        } else {
-                            // tail
-                            self.tail = self.data[key].newer;
-                            delete self.tail.older;
-                        }
+            var value;
+            if (conf.ttl !== 0 && (Date.now() - self.data[key].ts) >= self.ttl) {
+                if (self.data[key].newer) {
+                    if (self.data[key].older) {
+                        // in the middle of the list
+                        self.data[key].newer.older = self.data[key].older;
+                        self.data[key].older.newer = self.data[key].newer;
                     } else {
-                        // the first item
-                        if (self.data[key].older) {
-                            self.head = self.data[key].older;
-                            delete self.head.newer;
-                        } else {
-                            // 1 items
-                            delete self.head;
-                            delete self.tail;
-                        }
-                    }
-
-                    delete self.data[key];
-                    self.count = self.count - 1;
-
-                    if (callback) {
-                        callback(null, undefined);
+                        // tail
+                        self.tail = self.data[key].newer;
+                        delete self.tail.older;
                     }
                 } else {
-                    self.data[key].hit = self.data[key].hit + 1;
-
-                    if (callback) {
-                        callback(null, self.data[key].val);
+                    // the first item
+                    if (self.data[key].older) {
+                        self.head = self.data[key].older;
+                        delete self.head.newer;
+                    } else {
+                        // 1 items
+                        delete self.head;
+                        delete self.tail;
                     }
                 }
+
+                delete self.data[key];
+                self.count = self.count - 1;
             } else {
-                if (callback) {
-                    callback(null, undefined);
-                }
+                self.data[key].hit = self.data[key].hit + 1;
+                value = self.data[key].val;
             }
+            callback(null, value);
         });
     };
 };