Flows/subflows must preinitialise their context objects

Fixes #2513

If a node inside a subflow accessed its context object in its
constructor, the subflow-instance flow context would not yet
have been created. This would cause a place holder context
to get created on its behalf, but that place holder doesn't
have its parent set properly. This then breaks the usage
of $parent inside such a subflow.

This fix has changed it so flows (and subflows) create their
flow context as part of their initial creation. That ensures
it exists when individual nodes from the subflow are created,
allowing them to safely access their context.

This has also fixed a related issue where any attempt to use
$parent to access beyond the root parent would seemingly hang
as the callback was never being called. This would cause
messages to get stuck in flows. The fix ensures the callback
is used in the root context objects and undefined is returned.

packages/node_modules/@node-red/runtime/lib/nodes/context/index.js

@@ -420,15 +420,39 @@ function createRootContext() {
     Object.defineProperties(obj, {
         get: {
             value: function(key, storage, callback) {
+                if (!callback && typeof storage === 'function') {
+                    callback = storage;
+                    storage = undefined;
+                }
+                if (callback) {
+                    callback()
+                    return;
+                }
                 return undefined;
             }
         },
         set: {
             value: function(key, value, storage, callback) {
+                if (!callback && typeof storage === 'function') {
+                    callback = storage;
+                    storage = undefined;
+                }
+                if (callback) {
+                    callback()
+                    return
+                }
             }
         },
         keys: {
             value: function(storage, callback) {
+                if (!callback && typeof storage === 'function') {
+                    callback = storage;
+                    storage = undefined;
+                }
+                if (callback) {
+                    callback();
+                    return;
+                }
                 return undefined;
             }
         }
@@ -436,25 +460,48 @@ function createRootContext() {
     return obj;
 }
 
-function getContext(localId,flowId,parent) {
+/**
-    var contextId = localId;
+ * Get a flow-level context object.
+ * @param  {string} flowId       [description]
+ * @param  {string} parentFlowId the id of the parent flow. undefined
+ * @return {object}}             the context object
+ */
+function getFlowContext(flowId,parentFlowId) {
+    if (contexts.hasOwnProperty(flowId)) {
+        return contexts[flowId];
+    }
+    var parentContext = contexts[parentFlowId];
+    if (!parentContext) {
+        parentContext = createRootContext();
+        contexts[parentFlowId] = parentContext;
+        // throw new Error("Flow "+flowId+" is missing parent context "+parentFlowId);
+    }
+    var newContext = createContext(flowId,undefined,parentContext);
+    contexts[flowId] = newContext;
+    return newContext;
+
+}
+
+function getContext(nodeId, flowId) {
+    var contextId = nodeId;
     if (flowId) {
-        contextId = localId+":"+flowId;
+        contextId = nodeId+":"+flowId;
     }
     if (contexts.hasOwnProperty(contextId)) {
         return contexts[contextId];
     }
-    var newContext = createContext(contextId,undefined,parent);
+    var newContext = createContext(contextId);
+
     if (flowId) {
-        var node = flows.get(flowId);
+        var flowContext = contexts[flowId];
-        var parent = undefined;
+        if (!flowContext) {
-        if (node && node.type.startsWith("subflow:")) {
+            // This is most likely due to a unit test for a node which doesn't
-            parent = node.context().flow;
+            // initialise the flow properly.
+            // To keep things working, initialise the missing context.
+            // This *does not happen* in normal node-red operation
+            flowContext = createContext(flowId,undefined,createRootContext());
+            contexts[flowId] = flowContext;
         }
-        else {
-            parent = createRootContext();
-        }
-        var flowContext = getContext(flowId,undefined,parent);
         Object.defineProperty(newContext, 'flow', {
             value: flowContext
         });
@@ -466,6 +513,39 @@ function getContext(localId,flowId,parent) {
     return newContext;
 }
 
+//
+// function getContext(localId,flowId,parent) {
+//     var contextId = localId;
+//     if (flowId) {
+//         contextId = localId+":"+flowId;
+//     }
+//     console.log("getContext",localId,flowId,"known?",contexts.hasOwnProperty(contextId));
+//     if (contexts.hasOwnProperty(contextId)) {
+//         return contexts[contextId];
+//     }
+//     var newContext = createContext(contextId,undefined,parent);
+//     if (flowId) {
+//         var node = flows.get(flowId);
+//         console.log("flows,get",flowId,node&&node.type)
+//         var parent = undefined;
+//         if (node && node.type.startsWith("subflow:")) {
+//             parent = node.context().flow;
+//         }
+//         else {
+//             parent = createRootContext();
+//         }
+//         var flowContext = getContext(flowId,undefined,parent);
+//         Object.defineProperty(newContext, 'flow', {
+//             value: flowContext
+//         });
+//     }
+//     Object.defineProperty(newContext, 'global', {
+//         value: contexts['global']
+//     })
+//     contexts[contextId] = newContext;
+//     return newContext;
+// }
+
 function deleteContext(id,flowId) {
     if(!hasConfiguredStore){
         // only delete context if there's no configured storage.
@@ -517,6 +597,7 @@ module.exports = {
     load: load,
     listStores: listStores,
     get: getContext,
+    getFlowContext:getFlowContext,
     delete: deleteContext,
     clean: clean,
     close: close

packages/node_modules/@node-red/runtime/lib/nodes/flows/Flow.js

@@ -18,6 +18,7 @@ var clone = require("clone");
 var redUtil = require("@node-red/util").util;
 var flowUtil = require("./util");
 var events = require("../../events");
+const context = require('../context');
 
 var Subflow;
 var Log;
@@ -54,6 +55,8 @@ class Flow {
         this.catchNodes = [];
         this.statusNodes = [];
         this.path = this.id;
+        // Ensure a context exists for this flow
+        this.context = context.getFlowContext(this.id,this.parent.id);
     }
 
     /**

packages/node_modules/@node-red/runtime/lib/nodes/flows/Subflow.js

@@ -16,7 +16,7 @@
 
 const clone = require("clone");
 const Flow = require('./Flow').Flow;
-
+const context = require('../context');
 const util = require("util");
 
 const redUtil = require("@node-red/util").util;
@@ -227,6 +227,10 @@ class Subflow extends Flow {
         this.node.on("input", function(msg) { this.send(msg);});
         this.node.on("close", function() { this.status({}); })
         this.node.status = status => this.parent.handleStatus(this.node,status);
+        // Create a context instance
+        console.log("Node.context",this.type,"id:",this._alias||this.id,"z:",this.z)
+        this._context = context.get(this._alias||this.id,this.z);
+
 
         this.node._updateWires = this.node.updateWires;
 

test/unit/@node-red/runtime/lib/nodes/context/index_spec.js

@@ -32,17 +32,20 @@ describe('context', function() {
             return Context.close();
         });
         it('stores local property',function() {
+            var flowContext = Context.getFlowContext("flowA")
             var context1 = Context.get("1","flowA");
             should.not.exist(context1.get("foo"));
             context1.set("foo","test");
             context1.get("foo").should.equal("test");
         });
         it('stores local property - creates parent properties',function() {
+            var flowContext = Context.getFlowContext("flowA")
             var context1 = Context.get("1","flowA");
             context1.set("foo.bar","test");
             context1.get("foo").should.eql({bar:"test"});
         });
         it('deletes local property',function() {
+            var flowContext = Context.getFlowContext("flowA")
             var context1 = Context.get("1","flowA");
             context1.set("foo.abc.bar1","test1");
             context1.set("foo.abc.bar2","test2");
@@ -55,12 +58,14 @@ describe('context', function() {
             should.not.exist(context1.get("foo"));
         });
         it('stores flow property',function() {
+            var flowContext = Context.getFlowContext("flowA")
             var context1 = Context.get("1","flowA");
             should.not.exist(context1.flow.get("foo"));
             context1.flow.set("foo","test");
             context1.flow.get("foo").should.equal("test");
         });
         it('stores global property',function() {
+            var flowContext = Context.getFlowContext("flowA")
             var context1 = Context.get("1","flowA");
             should.not.exist(context1.global.get("foo"));
             context1.global.set("foo","test");
@@ -68,6 +73,7 @@ describe('context', function() {
         });
 
         it('keeps local context local', function() {
+            var flowContext = Context.getFlowContext("flowA")
             var context1 = Context.get("1","flowA");
             var context2 = Context.get("2","flowA");
 
@@ -79,6 +85,7 @@ describe('context', function() {
             should.not.exist(context2.get("foo"));
         });
         it('flow context accessible to all flow nodes', function() {
+            var flowContext = Context.getFlowContext("flowA")
             var context1 = Context.get("1","flowA");
             var context2 = Context.get("2","flowA");
 
@@ -91,6 +98,8 @@ describe('context', function() {
         });
 
         it('flow context not shared to nodes on other flows', function() {
+            var flowContextA = Context.getFlowContext("flowA")
+            var flowContextB = Context.getFlowContext("flowB")
             var context1 = Context.get("1","flowA");
             var context2 = Context.get("2","flowB");
 
@@ -103,6 +112,9 @@ describe('context', function() {
         });
 
         it('global context shared to all nodes', function() {
+            var flowContextA = Context.getFlowContext("flowA")
+            var flowContextB = Context.getFlowContext("flowB")
+
             var context1 = Context.get("1","flowA");
             var context2 = Context.get("2","flowB");
 
@@ -115,6 +127,7 @@ describe('context', function() {
         });
 
         it('context.flow/global are not enumerable', function() {
+            var flowContextA = Context.getFlowContext("flowA")
             var context1 = Context.get("1","flowA");
             Object.keys(context1).length.should.equal(0);
             Object.keys(context1.flow).length.should.equal(0);
@@ -122,6 +135,7 @@ describe('context', function() {
         })
 
         it('context.flow/global cannot be deleted', function() {
+            var flowContextA = Context.getFlowContext("flowA")
             var context1 = Context.get("1","flowA");
             delete context1.flow;
             should.exist(context1.flow);
@@ -130,6 +144,7 @@ describe('context', function() {
         })
 
         it('deletes context',function() {
+            var flowContextA = Context.getFlowContext("flowA")
             var context = Context.get("1","flowA");
             should.not.exist(context.get("foo"));
             context.set("foo","abc");
@@ -142,6 +157,7 @@ describe('context', function() {
         });
 
         it('enumerates context keys - sync', function() {
+            var flowContextA = Context.getFlowContext("flowA")
             var context = Context.get("1","flowA");
 
             var keys = context.keys();
@@ -160,6 +176,7 @@ describe('context', function() {
         });
 
         it('enumerates context keys - async', function(done) {
+            var flowContextA = Context.getFlowContext("flowA")
             var context = Context.get("1","flowA");
 
             var keys = context.keys(function(err,keys) {
@@ -183,6 +200,7 @@ describe('context', function() {
         it('should enumerate only context keys when GlobalContext was given - sync', function() {
             Context.init({functionGlobalContext: {foo:"bar"}});
             Context.load().then(function(){
+                var flowContextA = Context.getFlowContext("flowA")
                 var context = Context.get("1","flowA");
                 context.global.set("foo2","bar2");
                 var keys = context.global.keys();
@@ -195,6 +213,7 @@ describe('context', function() {
         it('should enumerate only context keys when GlobalContext was given - async', function(done) {
             Context.init({functionGlobalContext: {foo:"bar"}});
             Context.load().then(function(){
+                var flowContextA = Context.getFlowContext("flowA")
                 var context = Context.get("1","flowA");
                 context.global.set("foo2","bar2");
                 context.global.keys(function(err,keys) {
@@ -210,6 +229,7 @@ describe('context', function() {
         it('returns functionGlobalContext value if store value undefined', function() {
             Context.init({functionGlobalContext: {foo:"bar"}});
             return Context.load().then(function(){
+                var flowContextA = Context.getFlowContext("flowA")
                 var context = Context.get("1","flowA");
                 var v = context.global.get('foo');
                 v.should.equal('bar');
@@ -219,6 +239,7 @@ describe('context', function() {
         it('returns functionGlobalContext sub-value if store value undefined', function() {
             Context.init({functionGlobalContext: {foo:{bar:123}}});
             return Context.load().then(function(){
+                var flowContextA = Context.getFlowContext("flowA")
                 var context = Context.get("1","flowA");
                 var v = context.global.get('foo.bar');
                 should.equal(v,123);
@@ -227,40 +248,67 @@ describe('context', function() {
 
         describe("$parent", function() {
             it('should get undefined for $parent without key', function() {
+                var flowContextA = Context.getFlowContext("flowA")
+                var flowContextB = Context.getFlowContext("flowB","flowA")
                 var context0 = Context.get("0","flowA");
-                var context1 = Context.get("1","flowB", context0);
+                var context1 = Context.get("1","flowB");
                 var parent = context1.get("$parent");
                 should.equal(parent, undefined);
             });
 
             it('should get undefined for $parent of root', function() {
+                var flowContextA = Context.getFlowContext("flowA")
+                var flowContextB = Context.getFlowContext("flowB","flowA")
                 var context0 = Context.get("0","flowA");
-                var context1 = Context.get("1","flowB", context0);
+                var context1 = Context.get("1","flowB");
-                var parent = context1.get("$parent.$parent.K");
+                var parent = context1.flow.get("$parent.$parent.K");
                 should.equal(parent, undefined);
             });
 
-            it('should get value in $parent', function() {
+            it('should get undefined for $parent of root - callback', function(done) {
+                var flowContextA = Context.getFlowContext("flowA")
+                var flowContextB = Context.getFlowContext("flowB","flowA")
                 var context0 = Context.get("0","flowA");
-                var context1 = Context.get("1","flowB", context0);
+                var context1 = Context.get("1","flowB");
-                context0.set("K", "v");
+                context1.flow.get("$parent.$parent.K", function(err, result) {
-                var v = context1.get("$parent.K");
+                    try {
+                        should.equal(err, undefined);
+                        should.equal(result, undefined);
+                        done();
+                    } catch(err) {
+                        done(err);
+                    }
+                });
+
+            });
+
+            it('should get value in $parent', function() {
+                var flowContextA = Context.getFlowContext("flowA")
+                var flowContextB = Context.getFlowContext("flowB","flowA")
+                var context0 = Context.get("0","flowA");
+                var context1 = Context.get("1","flowB");
+                flowContextA.set("K", "v");
+                var v = context1.flow.get("$parent.K");
                 should.equal(v, "v");
             });
 
             it('should set value in $parent', function() {
+                var flowContextA = Context.getFlowContext("flowA")
+                var flowContextB = Context.getFlowContext("flowB","flowA")
                 var context0 = Context.get("0","flowA");
-                var context1 = Context.get("1","flowB", context0);
+                var context1 = Context.get("1","flowB");
-                context1.set("$parent.K", "v");
+                context1.flow.set("$parent.K", "v");
-                var v = context0.get("K");
+                var v = flowContextA.get("K");
                 should.equal(v, "v");
             });
 
             it('should not contain $parent in keys', function() {
+                var flowContextA = Context.getFlowContext("flowA")
+                var flowContextB = Context.getFlowContext("flowB","flowA")
                 var context0 = Context.get("0","flowA");
-                var context1 = Context.get("1","flowB", context0);
+                var context1 = Context.get("1","flowB");
                 var parent = context1.get("$parent");
-                context0.set("K0", "v0");
+                flowContextA.set("K0", "v0");
                 context1.set("K1", "v1");
                 var keys = context1.keys();
                 keys.should.have.length(1);
@@ -366,6 +414,7 @@ describe('context', function() {
             it('should ignore reserved storage name `_`', function(done) {
                 Context.init({contextStorage:{_:{module:testPlugin}}});
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow")
                     var context = Context.get("1","flow");
                     var cb = function(){}
                     context.set("foo","bar","_",cb);
@@ -452,6 +501,7 @@ describe('context', function() {
                 Context.init({contextStorage:contextStorage});
                 var cb = function(){done("An error occurred")}
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     context.set("foo","bar","test",cb);
                     context.get("foo","test",cb);
@@ -465,6 +515,7 @@ describe('context', function() {
             it('should store flow property to external context storage',function(done) {
                 Context.init({contextStorage:contextStorage});
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     var cb = function(){done("An error occurred")}
                     context.flow.set("foo","bar","test",cb);
@@ -479,6 +530,7 @@ describe('context', function() {
             it('should store global property to external context storage',function(done) {
                 Context.init({contextStorage:contextStorage});
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     var cb = function(){done("An error occurred")}
                     context.global.set("foo","bar","test",cb);
@@ -493,6 +545,7 @@ describe('context', function() {
             it('should store data to the default context when non-existent context storage was specified', function(done) {
                 Context.init({contextStorage:contextDefaultStorage});
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     var cb = function(){done("An error occurred")}
                     context.set("foo","bar","nonexist",cb);
@@ -510,6 +563,7 @@ describe('context', function() {
             it('should use the default context', function(done) {
                 Context.init({contextStorage:contextDefaultStorage});
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     var cb = function(){done("An error occurred")}
                     context.set("foo","bar","default",cb);
@@ -527,6 +581,7 @@ describe('context', function() {
             it('should use the alias of default context', function(done) {
                 Context.init({contextStorage:contextDefaultStorage});
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     var cb = function(){done("An error occurred")}
                     context.set("foo","alias",cb);
@@ -541,10 +596,11 @@ describe('context', function() {
                     done();
                 }).catch(done);
             });
-            
+
             it('should allow the store name to be provide in the key', function(done) {
                 Context.init({contextStorage:contextDefaultStorage});
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     var cb = function(){done("An error occurred")}
                     context.set("#:(test)::foo","bar");
@@ -561,6 +617,7 @@ describe('context', function() {
             it('should use default as the alias of other context', function(done) {
                 Context.init({contextStorage:contextAlias});
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     var cb = function(){done("An error occurred")}
                     context.set("foo","alias",cb);
@@ -575,6 +632,7 @@ describe('context', function() {
             it('should not throw an error using undefined storage for local context', function(done) {
                 Context.init({contextStorage:contextStorage});
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     var cb = function(){done("An error occurred")}
                     context.get("local","nonexist",cb);
@@ -584,6 +642,7 @@ describe('context', function() {
             it('should throw an error using undefined storage for flow context', function(done) {
                 Context.init({contextStorage:contextStorage});
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     var cb = function(){done("An error occurred")}
                     context.flow.get("flow","nonexist",cb);
@@ -595,6 +654,7 @@ describe('context', function() {
                 var fGC = { "foo": 456 };
                 Context.init({contextStorage:memoryStorage, functionGlobalContext:fGC });
                 Context.load().then(function() {
+                    var flowContext = Context.getFlowContext("flow");
                     var context = Context.get("1","flow");
                     // Get foo - should be value from fGC
                     var v = context.global.get("foo");
@@ -615,6 +675,7 @@ describe('context', function() {
                 var fGC = { "foo": 456 };
                 Context.init({contextStorage:memoryStorage, functionGlobalContext:fGC });
                 Context.load().then(function() {
+                    var flowContext = Context.getFlowContext("flow");
                     var context = Context.get("1","flow");
                     // Get foo - should be value from fGC
                     context.global.get("foo", function(err, v) {
@@ -647,6 +708,7 @@ describe('context', function() {
             it('should return multiple values if key is an array', function(done) {
                 Context.init({contextStorage:memoryStorage});
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     context.set("foo1","bar1","memory");
                     context.set("foo2","bar2","memory");
@@ -667,6 +729,7 @@ describe('context', function() {
                 var fGC = { "foo1": 456, "foo2": {"bar":789} };
                 Context.init({contextStorage:memoryStorage, functionGlobalContext:fGC });
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     context.global.get(["foo1","foo2.bar","foo3"], "memory", function(err,foo1,foo2,foo3){
                         if (err) {
@@ -685,6 +748,7 @@ describe('context', function() {
                 Context.init({contextStorage:contextStorage});
                 stubGet.onFirstCall().callsArgWith(2, "error2", "bar1");
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow")
                     var context =  Context.get("1","flow");
                     context.global.get(["foo1","foo2","foo3"], "memory", function(err,foo1,foo2,foo3){
                         if (err === "error2") {
@@ -702,6 +766,7 @@ describe('context', function() {
                 stubGet.onSecondCall().callsArgWith(2, null, "bar2");
                 stubGet.onThirdCall().callsArgWith(2, "error3");
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     context.get(["foo1","foo2","foo3"], "memory", function(err,foo1,foo2,foo3){
                         if (err === "error1") {
@@ -716,6 +781,7 @@ describe('context', function() {
             it('should store multiple properties if key and value are arrays', function(done) {
                 Context.init({contextStorage:memoryStorage});
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     context.set(["foo1","foo2","foo3"], ["bar1","bar2","bar3"], "memory", function(err){
                         if (err) {
@@ -739,6 +805,7 @@ describe('context', function() {
             it('should deletes multiple properties', function(done) {
                 Context.init({contextStorage:memoryStorage});
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     context.set(["foo1","foo2","foo3"], ["bar1","bar2","bar3"], "memory", function(err){
                         if (err) {
@@ -777,6 +844,7 @@ describe('context', function() {
             it('should use null for missing values if the value array is shorter than the key array', function(done) {
                 Context.init({contextStorage:memoryStorage});
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     context.set(["foo1","foo2","foo3"], ["bar1","bar2"], "memory", function(err){
                         if (err) {
@@ -804,6 +872,7 @@ describe('context', function() {
             it('should use null for missing values if the value is not array', function(done) {
                 Context.init({contextStorage:memoryStorage});
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     context.set(["foo1","foo2","foo3"], "bar1", "memory", function(err){
                         if (err) {
@@ -831,6 +900,7 @@ describe('context', function() {
             it('should ignore the extra values if the value array is longer than the key array', function(done) {
                 Context.init({contextStorage:memoryStorage});
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     context.set(["foo1","foo2","foo3"], ["bar1","bar2","bar3","ignored"], "memory", function(err){
                         if (err) {
@@ -859,6 +929,7 @@ describe('context', function() {
                 Context.init({contextStorage:contextStorage});
                 stubSet.onFirstCall().callsArgWith(3, "error2");
                 Context.load().then(function(){
+                    var flowContext = Context.getFlowContext("flow");
                     var context =  Context.get("1","flow");
                     context.set(["foo1","foo2","foo3"], ["bar1","bar2","bar3"], "memory", function(err){
                         if (err === "error2") {
@@ -873,6 +944,7 @@ describe('context', function() {
             it('should throw an error if callback of context.get is not a function', function (done) {
                 Context.init({ contextStorage: memoryStorage });
                 Context.load().then(function () {
+                    var flowContext = Context.getFlowContext("flow");
                     var context = Context.get("1", "flow");
                     context.get("foo", "memory", "callback");
                     done("should throw an error.");
@@ -884,6 +956,7 @@ describe('context', function() {
             it('should not throw an error if callback of context.get is not specified', function (done) {
                 Context.init({ contextStorage: memoryStorage });
                 Context.load().then(function () {
+                    var flowContext = Context.getFlowContext("flow");
                     var context = Context.get("1", "flow");
                     context.get("foo", "memory");
                     done();
@@ -893,6 +966,7 @@ describe('context', function() {
             it('should throw an error if callback of context.set is not a function', function (done) {
                 Context.init({ contextStorage: memoryStorage });
                 Context.load().then(function () {
+                    var flowContext = Context.getFlowContext("flow");
                     var context = Context.get("1", "flow");
                     context.set("foo", "bar", "memory", "callback");
                     done("should throw an error.");
@@ -904,6 +978,7 @@ describe('context', function() {
             it('should not throw an error if callback of context.set is not specified', function (done) {
                 Context.init({ contextStorage: memoryStorage });
                 Context.load().then(function () {
+                    var flowContext = Context.getFlowContext("flow");
                     var context = Context.get("1", "flow");
                     context.set("foo", "bar", "memory");
                     done();
@@ -913,6 +988,7 @@ describe('context', function() {
             it('should throw an error if callback of context.keys is not a function', function (done) {
                 Context.init({ contextStorage: memoryStorage });
                 Context.load().then(function () {
+                    var flowContext = Context.getFlowContext("flow");
                     var context = Context.get("1", "flow");
                     context.keys("memory", "callback");
                     done("should throw an error.");
@@ -924,6 +1000,7 @@ describe('context', function() {
             it('should not throw an error if callback of context.keys is not specified', function (done) {
                 Context.init({ contextStorage: memoryStorage });
                 Context.load().then(function () {
+                    var flowContext = Context.getFlowContext("flow");
                     var context = Context.get("1", "flow");
                     context.keys("memory");
                     done();
@@ -953,7 +1030,6 @@ describe('context', function() {
                 }).catch(done);
             });
         });
-
         describe('delete context',function(){
             it('should not call delete() when external context storage is used', function(done) {
                 Context.init({contextStorage:contextDefaultStorage});