Prevent the callback to be called twice

and add test cases

red/runtime/nodes/context/memory.js

@@ -30,19 +30,24 @@ Memory.prototype.close = function(){
 
 Memory.prototype.get = function(scope, key, callback) {
     var value;
+    var error;
     try{
         if(this.data[scope]){
             value = util.getMessageProperty(this.data[scope], key);
         }
     }catch(err){
         if(callback){
-            callback(err);
+            error = err;
         }else{
             throw err;
         }
     }
     if(callback){
+        if(error){
+            callback(error);
+        } else {
             callback(null, value);
+        }
     } else {
         return value;
     }
@@ -52,22 +57,24 @@ Memory.prototype.set =function(scope, key, value, callback) {
     if(!this.data[scope]){
         this.data[scope] = {};
     }
+    var error;
     try{
         util.setMessageProperty(this.data[scope],key,value);
     }catch(err){
         if(callback){
-            callback(err);
+            error = err;
         }else{
             throw err;
         }
     }
     if(callback){
-        callback(null);
+        callback(error || null);
     }
 };
 
 Memory.prototype.keys = function(scope, callback){
     var values = [];
+    var error;
     try{
         if(this.data[scope]){
             if (scope !== "global") {
@@ -80,13 +87,17 @@ Memory.prototype.keys = function(scope, callback){
         }
     }catch(err){
         if(callback){
-            callback(err);
+            error = err;
         }else{
             throw err;
         }
     }
     if(callback){
+        if(error){
+            callback(error);
+        } else {
             callback(null, values);
+        }
     } else {
         return values;
     }

test/red/runtime/nodes/context/memory_spec.js

@@ -32,6 +32,7 @@ describe('memory',function() {
     });
 
     describe('#get/set',function() {
+        describe('sync',function() {
             it('should store property',function() {
                 should.not.exist(context.get("nodeX","foo"));
                 context.set("nodeX","foo","test");
@@ -64,9 +65,50 @@ describe('memory',function() {
                 context.get("nodeX","foo").should.equal("testX");
                 context.get("nodeY","foo").should.equal("testY");
             });
+
+            it('should thorw the error if the error occurs', function() {
+                try{
+                    context.set("nodeX",".foo","test");
+                    should.fail("Error was not thrown");
+                }catch(err){
+                    should.exist(err);
+                    try{
+                        context.get("nodeX",".foo");
+                        should.fail("Error was not thrown");
+                    }catch(err){
+                        should.exist(err);
+                    }
+                }
+            });
+        });
+
+        describe('async',function() {
+            it('should store property',function(done) {
+                context.get("nodeX","foo",function(err, value){
+                    should.not.exist(value);
+                    context.set("nodeX","foo","test",function(err){
+                        context.get("nodeX","foo",function(err, value){
+                            value.should.equal("test");
+                            done();
+                        });
+                    });
+                });
+            });
+
+            it('should pass the error to callback if the error occurs',function(done) {
+                context.set("nodeX",".foo","test",function(err, value){
+                    should.exist(err);
+                    context.get("nodeX",".foo",function(err){
+                        should.exist(err);
+                        done();
+                    });
+                });
+            });
+        });
     });
 
     describe('#keys',function() {
+        describe('sync',function() {
             it('should enumerate context keys', function() {
                 var keys = context.keys("nodeX");
                 keys.should.be.an.Array();
@@ -102,7 +144,29 @@ describe('memory',function() {
                 keysY.should.have.length(1);
                 keysY[0].should.equal("hoge");
             });
+        });
 
+        describe('async',function() {
+            it('should enumerate context keys', function(done) {
+                context.keys("nodeX", function(err, keys) {
+                    keys.should.be.an.Array();
+                    keys.should.be.empty();
+                    context.set("nodeX", "foo", "bar", function(err) {
+                        context.keys("nodeX", function(err, keys) {
+                            keys.should.have.length(1);
+                            keys[0].should.equal("foo");
+                            context.set("nodeX","abc.def","bar",function(err){
+                                context.keys("nodeX",function(err, keys){
+                                    keys.should.have.length(2);
+                                    keys[1].should.equal("abc");
+                                    done();
+                                });
+                            });
+                        });
+                    });
+                });
+            });
+        });
     });
 
     describe('#delete',function() {