Add counter to onError trigger to break possible loops

libraries/Microsoft.Bot.Builder.Dialogs.Adaptive/Schemas/TriggerConditions/Microsoft.OnError.schema

@@ -3,5 +3,16 @@
     "$role": [ "implements(Microsoft.ITrigger)", "extends(Microsoft.OnCondition)" ],
     "title": "On error",
     "description": "Action to perform when an 'Error' dialog event occurs.",
-    "type": "object"
+    "type": "object",
+    "properties": {
+        "executionLimit": {
+            "$ref": "schema:#/definitions/numberExpression",
+            "title": "Execution limit",
+            "description": "Number of executions allowed for this trigger. Used to break loops in case of errors inside the trigger.",
+            "examples": [
+                3,
+                "=f(x)"
+            ]
+        }
+    }
 }

libraries/Microsoft.Bot.Builder.Dialogs.Adaptive/Schemas/TriggerConditions/Microsoft.OnError.uischema

@@ -3,7 +3,8 @@
     "form": {
         "order": [
             "condition",
-            "*"
+            "*",
+            "executionLimit"
         ],
         "hidden": [
             "actions"

libraries/Microsoft.Bot.Builder.Dialogs.Adaptive/TriggerConditions/OnError.cs

@@ -3,6 +3,8 @@
 
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
+using System.Threading.Tasks;
+using AdaptiveExpressions.Properties;
 using Newtonsoft.Json;
 
 namespace Microsoft.Bot.Builder.Dialogs.Adaptive.Conditions
@@ -31,6 +33,26 @@ public OnError(List<Dialog> actions = null, string condition = null, [CallerFile
         {
         }
 
+        /// <summary>
+        /// Gets or sets the number of executions allowed. Used to avoid infinite loops in case of error.
+        /// </summary>
+        /// <value>The number of executions allowed for this trigger.</value>
+        [JsonProperty("executionLimit")]
+        public NumberExpression ExecutionLimit { get; set; } = new NumberExpression();
+
+        /// <summary>
+        /// Method called to execute the rule's actions.
+        /// </summary>
+        /// <param name="actionContext">Context.</param>
+        /// <returns>A <see cref="Task"/> with plan change list.</returns>
+        public override Task<List<ActionChangeList>> ExecuteAsync(ActionContext actionContext)
+        {
+            // 10 is the default number of executions we'll allow before breaking the loop.
+            var limit = ExecutionLimit.Value > 0 ? ExecutionLimit.Value : 10;
+            actionContext.State.SetValue(TurnPath.ExecutionLimit, limit);
+            return base.ExecuteAsync(actionContext);
+        }
+
         /// <summary>
         /// Called when a change list is created.
         /// </summary>

libraries/Microsoft.Bot.Builder.Dialogs/DialogExtensions.cs

@@ -12,6 +12,7 @@
 using Microsoft.Bot.Builder.Skills;
 using Microsoft.Bot.Connector.Authentication;
 using Microsoft.Bot.Schema;
+using Newtonsoft.Json.Linq;
 
 namespace Microsoft.Bot.Builder.Dialogs
 {
@@ -64,6 +65,8 @@ internal static async Task<DialogTurnResult> InternalRunAsync(ITurnContext turnC
             // or we have had an exception AND there was an OnError action which captured the error.  We need to continue the 
             // turn based on the actions the OnError handler introduced.
             var endOfTurn = false;
+            var errorHandlerCalled = 0;
+
             while (!endOfTurn)
             {
                 try
@@ -79,8 +82,29 @@ internal static async Task<DialogTurnResult> InternalRunAsync(ITurnContext turnC
                     var innerExceptions = new List<Exception>();
                     try
                     {
+                        errorHandlerCalled++;
+
                         // fire error event, bubbling from the leaf.
                         handled = await dialogContext.EmitEventAsync(DialogEvents.Error, err, bubble: true, fromLeaf: true, cancellationToken: cancellationToken).ConfigureAwait(false);
+
+                        var turnObject = (JObject)turnContext.TurnState["turn"];
+
+                        var executionLimit = 0;
+
+                        foreach (var childToken in turnObject.Children<JProperty>())
+                        {
+                            if (childToken.Name == "executionLimit")
+                            {
+                                executionLimit = (int)childToken.Value;
+                            }
+                        }
+
+                        if (executionLimit > 0 && errorHandlerCalled > executionLimit)
+                        {
+                            // if the errorHandler has being called multiple times, there's an error inside the onError.
+                            // We should throw the exception and break the loop.
+                            handled = false;
+                        }
                     }
 #pragma warning disable CA1031 // Do not catch general exception types (capture the error in case it's not handled properly)
                     catch (Exception emitErr)

libraries/Microsoft.Bot.Builder.Dialogs/Memory/TurnPath.cs

@@ -72,6 +72,11 @@ public class TurnPath
         /// </summary>
         public const string ActivityProcessed = "turn.activityProcessed";
 
+        /// <summary>
+        /// Used to limit the execution of a trigger avoiding infinite loops in case of errors.
+        /// </summary>
+        public const string ExecutionLimit = "turn.executionLimit";
+
         /// <summary>
         /// The result from the last dialog that was called.
         /// </summary>

tests/Microsoft.Bot.Builder.Dialogs.Adaptive.Tests/ConditionalsTests.cs

@@ -89,6 +89,18 @@ public async Task ConditionalsTests_OnChooseIntent()
             await TestUtils.RunTestScript(_resourceExplorerFixture.ResourceExplorer);
         }
 
+        [Fact]
+        public async Task ConditionalsTests_OnErrorLoop()
+        {
+            await TestUtils.RunTestScript(_resourceExplorerFixture.ResourceExplorer);
+        }
+
+        [Fact]
+        public async Task ConditionalsTests_OnErrorLoopDefaultLimit()
+        {
+            await TestUtils.RunTestScript(_resourceExplorerFixture.ResourceExplorer);
+        }
+
         [Fact]
         public void OnConditionWithCondition()
         {

tests/Microsoft.Bot.Builder.Dialogs.Adaptive.Tests/Tests/ConditionalsTests/ConditionalsTests_OnErrorLoop.test.dialog

@@ -0,0 +1,65 @@
+{
+    "$schema": "../../../tests.schema",
+    "$kind": "Microsoft.Test.Script",
+    "dialog": {
+        "$kind": "Microsoft.AdaptiveDialog",
+        "id": "ErrorLoop",
+        "autoEndDialog": true,
+        "defaultResultProperty": "dialog.result",
+        "triggers": [
+            {
+                "$kind": "Microsoft.OnBeginDialog",
+                "actions": [
+                    {
+                        "$kind": "Microsoft.SendActivity",
+                        "activity": "Throw Exception in BeginDialog."
+                    },
+                    {
+                        "$kind": "Microsoft.ThrowException",
+                        "errorValue": "Exception in BeginDialog."
+                    }
+                ]
+            },
+            {
+                "$kind": "Microsoft.OnError",
+                "actions": [
+                    {
+                        "$kind": "Microsoft.SendActivity",
+                        "activity": "Throw Exception in OnError."
+                    },
+                    {
+                        "$kind": "Microsoft.ThrowException",
+                        "errorValue": "Exception in OnError."
+                    }
+                ],
+                "executionLimit": 3
+            }
+        ]
+    },
+    "script": [
+        {
+            "$kind": "Microsoft.Test.UserSays",
+            "text": "hi"
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Throw Exception in BeginDialog."
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Throw Exception in OnError."
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Throw Exception in OnError."
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Throw Exception in OnError."
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Exception in OnError."
+        }
+    ]
+}

tests/Microsoft.Bot.Builder.Dialogs.Adaptive.Tests/Tests/ConditionalsTests/ConditionalsTests_OnErrorLoopDefaultLimit.test.dialog

@@ -0,0 +1,92 @@
+{
+    "$schema": "../../../tests.schema",
+    "$kind": "Microsoft.Test.Script",
+    "dialog": {
+        "$kind": "Microsoft.AdaptiveDialog",
+        "id": "ErrorLoop",
+        "autoEndDialog": true,
+        "defaultResultProperty": "dialog.result",
+        "triggers": [
+            {
+                "$kind": "Microsoft.OnBeginDialog",
+                "actions": [
+                    {
+                        "$kind": "Microsoft.SendActivity",
+                        "activity": "Throw Exception in BeginDialog."
+                    },
+                    {
+                        "$kind": "Microsoft.ThrowException",
+                        "errorValue": "Exception in BeginDialog."
+                    }
+                ]
+            },
+            {
+                "$kind": "Microsoft.OnError",
+                "actions": [
+                    {
+                        "$kind": "Microsoft.SendActivity",
+                        "activity": "Throw Exception in OnError."
+                    },
+                    {
+                        "$kind": "Microsoft.ThrowException",
+                        "errorValue": "Exception in OnError."
+                    }
+                ]
+            }
+        ]
+    },
+    "script": [
+        {
+            "$kind": "Microsoft.Test.UserSays",
+            "text": "hi"
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Throw Exception in BeginDialog."
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Throw Exception in OnError."
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Throw Exception in OnError."
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Throw Exception in OnError."
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Throw Exception in OnError."
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Throw Exception in OnError."
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Throw Exception in OnError."
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Throw Exception in OnError."
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Throw Exception in OnError."
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Throw Exception in OnError."
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Throw Exception in OnError."
+        },
+        {
+            "$kind": "Microsoft.Test.AssertReply",
+            "text": "Exception in OnError."
+        }
+    ]
+}

tests/tests.schema

@@ -6498,6 +6498,15 @@
         }
       },
       "properties": {
+        "executionLimit": {
+          "$ref": "#/definitions/numberExpression",
+          "title": "Execution limit",
+          "description": "Number of executions allowed for this trigger. Used to break loops in case of errors inside the trigger.",
+          "examples": [
+            3,
+            "=f(x)"
+          ]
+        },
         "condition": {
           "$ref": "#/definitions/condition",
           "title": "Condition",

tests/tests.uischema

@@ -1166,7 +1166,8 @@
       "label": "Error occurred",
       "order": [
         "condition",
-        "*"
+        "*",
+        "executionLimit"
       ],
       "subtitle": "Error event"
     },