feat: change transform error handling (#699)

* feat: change transformation exception handling

* Update CreateCohortDistributionTests.cs

Author: will-larkin-nhs

application/CohortManager/src/Functions/CohortDistributionServices/CreateCohortDistribution/CreateCohortDistribution.cs

@@ -91,10 +91,7 @@ await HandleErrorResponseAsync($"Unable to add to cohort distribution. As partic
             // Transformation
             var transformedParticipant = await _CohortDistributionHelper.TransformParticipantAsync(serviceProvider, participantData);
             if (transformedParticipant == null)
-            {
-                await HandleErrorResponseAsync("The transformed participant returned null from the transform participant function", transformedParticipant, basicParticipantCsvRecord.FileName);
                 return;
-            }
 
             // Add to cohort distribution table
             var cohortAddResponse = await AddCohortDistribution(transformedParticipant);

application/CohortManager/src/Functions/CohortDistributionServices/TransformDataService/TransformDataService.cs

@@ -98,6 +98,12 @@ public async Task<HttpResponseData> RunAsync([HttpTrigger(AuthorizationLevel.Ano
             }
             return _createResponse.CreateHttpResponse(HttpStatusCode.Accepted, req, "");
         }
+        catch (ArgumentException ex)
+        {
+            _logger.LogWarning(ex, "An error occurred during transformation");
+            await _exceptionHandler.CreateSystemExceptionLogFromNhsNumber(ex, participant.NhsNumber, "", "", JsonSerializer.Serialize(participant));
+            return _createResponse.CreateHttpResponse(HttpStatusCode.Accepted, req);
+        }
         catch (TransformationException ex)
         {
             _logger.LogWarning(ex, "An error occurred during transformation");
@@ -203,7 +209,7 @@ private static CohortDistributionParticipant TransformAddress(CohortDistribution
             string.IsNullOrEmpty(requestParticipant.AddressLine5))
         {
             if (requestParticipant.Postcode != databaseParticipant.PostCode)
-                throw new ArgumentException("Participant has an empty address and postcode does not match existing record");
+                throw new TransformationException("Participant has an empty address and postcode does not match existing record");
 
             requestParticipant.AddressLine1 = databaseParticipant.AddressLine1;
             requestParticipant.AddressLine2 = databaseParticipant.AddressLine2;

application/CohortManager/src/Functions/CohortDistributionServices/TransformDataService/TransformString.cs

@@ -66,17 +66,14 @@ private async Task<string> CheckParticipantCharactersAsync(string stringField)
             ParticipantUpdated = true;
             // Special characters that need to be handled separately
             if (stringField.Contains(@"\E\") || stringField.Contains(@"\T\"))
-            {
-                throw new ArgumentException("Participant contains illegal characters");
-            }
+                throw new ArgumentException($"Participant contains illegal characters");
 
             var transformedField = await TransformCharactersAsync(stringField);
 
             // Check to see if there are any unhandled invalid chars
             if (!Regex.IsMatch(transformedField, allowedCharacters, RegexOptions.None, matchTimeout))
-            {
                 throw new ArgumentException("Participant contains illegal characters");
-            }
+                
             return transformedField;
         }
     }

tests/UnitTests/CohortDistributionTests/CreateCohortDistributionTests/CreateCohortDistributionTests.cs

@@ -172,7 +172,7 @@ public async Task RunAsync_AllocateServiceProviderToParticipantRequestFails_Retu
     }
 
     [TestMethod]
-    public async Task RunAsync_TransformDataServiceRequestFails_LogError()
+    public async Task RunAsync_TransformDataServiceRequestFails_ReturnEarly()
     {
         // Arrange
         _cohortDistributionHelper
@@ -192,12 +192,8 @@ public async Task RunAsync_TransformDataServiceRequestFails_LogError()
         // Act
         await _sut.RunAsync(_requestBody);
 
-        _logger.Verify(x => x.Log(It.Is<LogLevel>(l => l == LogLevel.Error),
-            It.IsAny<EventId>(),
-            It.Is<It.IsAnyType>((v, t) => v.ToString().Contains("The transformed participant returned null from the transform participant function")),
-            It.IsAny<Exception>(),
-            It.IsAny<Func<It.IsAnyType, Exception, string>>()),
-        Times.Once);
+        // Assert
+        _callFunction.Verify(x => x.SendPost("AddCohortDistributionURL", It.IsAny<string>()), Times.Never);
     }
 
     [TestMethod]