adding caching.keys() function (issue #6)

lib/caching.js

@@ -1,3 +1,4 @@
+/*jshint maxcomplexity:10*/
 var caching = function (args) {
     args = args || {};
     var self = {};
@@ -61,6 +62,10 @@ var caching = function (args) {
         self.reset = self.store.reset.bind(self.store);
     }
 
+    if (typeof self.store.keys === 'function') {
+        self.keys = self.store.keys.bind(self.store);
+    }
+
     return self;
 };
 

lib/stores/memory.js

@@ -39,6 +39,17 @@ var memory_store = function (args) {
         }
     };
 
+    self.keys = function (cb) {
+        var keys = lru_cache.keys();
+        if (cb) {
+            process.nextTick(function () {
+                cb(null, keys);
+            });
+        } else {
+            return keys;
+        }
+    };
+
     return self;
 };
 

test/caching.unit.js

@@ -1,6 +1,7 @@
 // TODO: These are really a mix of unit and integration tests.
 
 var assert = require('assert');
+var async = require('async');
 var sinon = require('sinon');
 var support = require('./support');
 var check_err = support.check_err;
@@ -132,7 +133,7 @@ describe("caching", function () {
             });
         });
 
-        it("lets us clear the cache without a callback", function (done) {
+        it("lets us clear the cache without a callback (memory store only)", function (done) {
             cache.reset();
             setTimeout(function () {
                 cache.get(key, function (err, result) {
@@ -147,6 +148,43 @@ describe("caching", function () {
         });
     });
 
+    describe("keys()", function () {
+        var key_count;
+        var saved_keys = [];
+
+        beforeEach(function (done) {
+            key_count = 10;
+            var processed = 0;
+
+            cache = caching({store: 'memory'});
+
+            function is_done() {
+                return processed === key_count;
+            }
+
+            async.until(is_done, function (cb) {
+                processed += 1;
+                key = support.random.string(20);
+                saved_keys.push(key);
+                value = support.random.string();
+                cache.set(key, value, cb);
+            }, done);
+        });
+
+        it("calls back with all keys in cache", function (done) {
+            cache.keys(function (err, keys) {
+                check_err(err);
+                assert.deepEqual(keys.sort, saved_keys.sort);
+                done();
+            });
+        });
+
+        it("lets us get the keys without a callback (memory store only)", function () {
+            var keys = cache.keys();
+            assert.deepEqual(keys.sort, saved_keys.sort);
+        });
+    });
+
     describe("wrap()", function () {
         describe("using memory (lru-cache) store", function () {
             var memory_store_stub;
@@ -166,7 +204,7 @@ describe("caching", function () {
                 memory_store.create.restore();
             });
 
-            it("calls back with the result of a function", function (done) {
+            it("calls back with the result of the wrapped function", function (done) {
                 cache.wrap(key, function (cb) {
                     methods.get_widget(name, cb);
                 }, function (err, widget) {