From a8b3cbab749239b79aed93e41a8ee843e11244e9 Mon Sep 17 00:00:00 2001
From: Sipke Schoorstra <sipkeschoorstra@outlook.com>
Date: Sun, 10 Sep 2023 21:31:57 +0200
Subject: [PATCH] Add request exception handling to SendHttpRequest activity

---
 .../Elsa.Http/Activities/FlowSendHttpRequest.cs |  8 +++++++-
 .../Elsa.Http/Activities/SendHttpRequest.cs     | 17 +++++++++++------
 .../Elsa.Http/Activities/SendHttpRequestBase.cs | 11 +++++++++++
 3 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/src/modules/Elsa.Http/Activities/FlowSendHttpRequest.cs b/src/modules/Elsa.Http/Activities/FlowSendHttpRequest.cs
index 017a87803..afc2ce4d3 100644
--- a/src/modules/Elsa.Http/Activities/FlowSendHttpRequest.cs
+++ b/src/modules/Elsa.Http/Activities/FlowSendHttpRequest.cs
@@ -36,11 +36,17 @@ public class FlowSendHttpRequest : SendHttpRequestBase
         await context.CompleteActivityWithOutcomesAsync(outcome);
     }
 
+    /// <inheritdoc />
+    protected override async ValueTask HandleRequestExceptionAsync(ActivityExecutionContext context, HttpRequestException exception)
+    {
+        await context.CompleteActivityWithOutcomesAsync("Failed to connect");
+    }
+
     private static ValueTask<IDictionary<string, object>> GetExpectedStatusCodesOptionsAsync(PropertyInfo property, CancellationToken cancellationToken = default)
     {
         var options = new Dictionary<string, object>
         {
-            [nameof(DynamicOutcomesOptions)] = new DynamicOutcomesOptions(new[]{"Unmatched status code", "Done"})
+            [nameof(DynamicOutcomesOptions)] = new DynamicOutcomesOptions(new[]{"Unmatched status code", "Failed to connect", "Done"})
         };
         
         return new(options);
diff --git a/src/modules/Elsa.Http/Activities/SendHttpRequest.cs b/src/modules/Elsa.Http/Activities/SendHttpRequest.cs
index cd966c245..eacbd0834 100644
--- a/src/modules/Elsa.Http/Activities/SendHttpRequest.cs
+++ b/src/modules/Elsa.Http/Activities/SendHttpRequest.cs
@@ -33,6 +33,11 @@ public class SendHttpRequest : SendHttpRequestBase
     [Port]
     public IActivity? UnmatchedStatusCode { get; set; }
 
+    /// <summary>
+    /// The activity to execute when the HTTP request fails to connect.
+    /// </summary>
+    public IActivity? FailedToConnect { get; set; }
+
     /// <inheritdoc />
     protected override async ValueTask HandleResponseAsync(ActivityExecutionContext context, HttpResponseMessage response)
     {
@@ -41,15 +46,15 @@ public class SendHttpRequest : SendHttpRequestBase
         var matchingCase = expectedStatusCodes.FirstOrDefault(x => x.StatusCode == statusCode);
         var activity = matchingCase != null ? matchingCase.Activity : UnmatchedStatusCode;
 
-        if (activity == null)
-        {
-            await context.CompleteActivityAsync();
-            return;
-        }
-
         await context.ScheduleActivityAsync(activity, OnChildActivityCompletedAsync);
     }
 
+    /// <inheritdoc />
+    protected override async ValueTask HandleRequestExceptionAsync(ActivityExecutionContext context, HttpRequestException exception)
+    {
+        await context.ScheduleActivityAsync(FailedToConnect, OnChildActivityCompletedAsync);
+    }
+
     private async ValueTask OnChildActivityCompletedAsync(ActivityCompletedContext context)
     {
         await context.TargetContext.CompleteActivityAsync();
diff --git a/src/modules/Elsa.Http/Activities/SendHttpRequestBase.cs b/src/modules/Elsa.Http/Activities/SendHttpRequestBase.cs
index 59c5a5df2..b24161e83 100644
--- a/src/modules/Elsa.Http/Activities/SendHttpRequestBase.cs
+++ b/src/modules/Elsa.Http/Activities/SendHttpRequestBase.cs
@@ -84,6 +84,11 @@ public abstract class SendHttpRequestBase : Activity<HttpResponseMessage>
     /// </summary>
     protected abstract ValueTask HandleResponseAsync(ActivityExecutionContext context, HttpResponseMessage response);
 
+    /// <summary>
+    /// Handles an exception that occurred while sending the request.
+    /// </summary>
+    protected abstract ValueTask HandleRequestExceptionAsync(ActivityExecutionContext context, HttpRequestException exception);
+
     private async Task TrySendAsync(ActivityExecutionContext context)
     {
         var request = PrepareRequest(context);
@@ -100,6 +105,12 @@ public abstract class SendHttpRequestBase : Activity<HttpResponseMessage>
 
             await HandleResponseAsync(context, response);
         }
+        catch(HttpRequestException e)
+        {
+            context.AddExecutionLogEntry("Error", e.Message, payload: new { StackTrace = e.StackTrace });
+            context.JournalData.Add("Error", e.Message);
+            await HandleRequestExceptionAsync(context, e);
+        }
         catch (TaskCanceledException e)
         {
             context.JournalData.Add("Cancelled", true);