Improve exception handling

DPE/DPEWebClient.cs

@@ -18,8 +18,8 @@ namespace pEp.DPE
         /// </summary>
         /// <param name="patch">The patch to reject.</param>
         /// <param name="me">The own identity that rejects the patch.</param>
-        /// <exception cref="ArgumentNullException" />
-        /// <exception cref="HttpRequestException" />
+        /// <exception cref="ArgumentNullException">The post URI is null.</exception>
+        /// <exception cref="HttpRequestException">The HTTP request failed.</exception>
         /// <returns>The Http response.</returns>
         public static async Task<HttpResponseMessage> RejectPatch(Patch patch, PEPIdentity me)
         {

DPE/DistributedPolicyEngine.cs

@@ -145,7 +145,7 @@ namespace pEp.DPE
         {
             Outlook.Folder inbox = null;
             Outlook.Items items = null;
-            
+
             try
             {
                 inbox = Globals.ThisAddIn.Application.Session.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderInbox) as Outlook.Folder;
@@ -168,7 +168,7 @@ namespace pEp.DPE
                     // Now find the one with the respective patch id
                     string filter = string.Format("[{0}] = '{1}'", MailItemExtensions.USER_PROPERTY_KEY_DPE_PATCH_ID, patch.Id);
                     items = items.Restrict(filter);
-                    
+
                     if (items.Count > 1)
                     {
                         Log.Error("GetPatchMailItem: More than one item found with patch id " + patch.Id);
@@ -206,42 +206,32 @@ namespace pEp.DPE
         /// <param name="patch">The patch to post.</param>
         /// <param name="me">The own identity.</param>
         /// <param name="postAction">The POST action to perform.</param>
-        /// <returns></returns>
-        private async Task<Exception> PostAsync(Patch patch, PEPIdentity me, PostAction postAction)
+        /// <exception cref="HttpRequestException">The HTTP request failed.</exception>
+        private async Task PostAsync(Patch patch, PEPIdentity me, PostAction postAction)
         {
             // Determine the correct method to execute
-            Task<HttpResponseMessage> postTask = null;
+            HttpResponseMessage httpResponseMessage = null;
             switch (postAction)
             {
                 case PostAction.Reject:
-                    postTask = DPEWebClient.RejectPatch(patch, me);
+                    httpResponseMessage = await DPEWebClient.RejectPatch(patch, me);
                     break;
                 case PostAction.Suggest:
-                    postTask = DPEWebClient.SuggestPatch(patch, me);
+                    httpResponseMessage = await DPEWebClient.SuggestPatch(patch, me);
                     break;
                 case PostAction.Support:
-                    postTask = DPEWebClient.SupportPatch(patch, me);
+                    httpResponseMessage = await DPEWebClient.SupportPatch(patch, me);
                     break;
                 default:
                     Log.ErrorAndFailInDebugMode("PostAsync: Unknown post action.");
                     break;
             }
 
-            // Execute the task and return status
-            return await postTask.ContinueWith((task) =>
+            if (httpResponseMessage.StatusCode != HttpStatusCode.OK)
             {
-                if (task.Exception != null)
-                {
-                    Log.Error("ExecuteAsync: Error executing POST of type " + Enum.GetName(typeof(PostAction), postAction));
-                    return task.Exception;
-                }
-                else
-                {
-                    return (task.Result.StatusCode != HttpStatusCode.OK) ?
-                           new Exception(Enum.GetName(typeof(HttpStatusCode), task.Result.StatusCode)) :
-                           null;
-                }
-            });
+                Log.Error("PostAsync: Status code is " + Enum.GetName(typeof(HttpStatusCode), httpResponseMessage.StatusCode));
+                throw new HttpRequestException(Enum.GetName(typeof(HttpStatusCode), httpResponseMessage.StatusCode));
+            }
         }
 
         /// <summary>
@@ -249,9 +239,15 @@ namespace pEp.DPE
         /// </summary>
         /// <param name="patch">The patch to reject.</param>
         /// <param name="me">The own identity that rejects the patch.</param>
+        /// <exception cref="HttpRequestException">The HTTP request failed.</exception>
+        /// <exception cref="UpdatePatchMailItemException">The update of the mail item failed.</exception>
         public async Task Reject(Patch patch, PEPIdentity me)
         {
-            if (await this.PostAsync(patch, me, PostAction.Reject) is Exception ex)
+            try
+            {
+                await this.PostAsync(patch, me, PostAction.Reject);
+            }
+            catch (HttpRequestException ex)
             {
                 throw ex;
             }
@@ -262,7 +258,7 @@ namespace pEp.DPE
             }
             else
             {
-                throw new Exception("Error updating patch mail item.");
+                throw new UpdatePatchMailItemException("Error updating patch mail item.");
             }
         }
 
@@ -318,9 +314,14 @@ namespace pEp.DPE
         /// </summary>
         /// <param name="patch">The patch to suggest.</param>
         /// <param name="me">The own identity that suggests the patch.</param>
+        /// <exception cref="HttpRequestException">The HTTP request failed.</exception>
         public async Task Suggest(Patch patch, PEPIdentity me)
         {
-            if (await this.PostAsync(patch, me, PostAction.Suggest) is Exception ex)
+            try
+            {
+                await this.PostAsync(patch, me, PostAction.Suggest);
+            }
+            catch (HttpRequestException ex)
             {
                 throw ex;
             }
@@ -333,20 +334,26 @@ namespace pEp.DPE
         /// </summary>
         /// <param name="patch">The patch to support.</param>
         /// <param name="me">The own identity that supports the patch.</param>
+        /// <exception cref="HttpRequestException">The HTTP request failed.</exception>
+        /// <exception cref="UpdatePatchMailItemException">The update of the mail item failed.</exception>
         public async Task Support(Patch patch, PEPIdentity me)
         {
-            if (await this.PostAsync(patch, me, PostAction.Support) is Exception ex)
+            try
+            {
+                await this.PostAsync(patch, me, PostAction.Support);
+            }
+            catch (HttpRequestException ex)
             {
                 throw ex;
             }
-            
+
             if (this.UpdatePatchMailItem(patch, PatchStatus.Supported))
             {
                 AdapterExtensions.ShowNotification("Patch supported", patch.CommitMessage);
             }
             else
             {
-                throw new Exception("Error updating patch mail item.");
+                throw new UpdatePatchMailItemException("Error updating patch mail item.");
             }
         }
 
@@ -362,5 +369,15 @@ namespace pEp.DPE
         }
 
         #endregion
+
+        /// <summary>
+        /// Custom exception for when the update of the patch mail item fails.
+        /// </summary>
+        public class UpdatePatchMailItemException : Exception
+        {
+            public UpdatePatchMailItemException(string message) : base(message)
+            {
+            }
+        }
     }
 }
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