Use AssertionScope to always include response.DebugInformation in the response body Should() assertions. This changes the way assertions are executed though, reporting on all ALL the failures. Since we do quite a few assertions in a single method this would become noisy so we hack the message to only include the first failure as before (#3408)

(cherry picked from commit df95930)

Author: Mpdreamz

src/Tests/Tests/Framework/EndpointTests/ApiIntegrationTestBase.cs

@@ -6,6 +6,7 @@
 using Elastic.Xunit.XunitPlumbing;
 using Elasticsearch.Net;
 using FluentAssertions;
+using FluentAssertions.Execution;
 using Nest;
 using Tests.Core.Client;
 using Tests.Core.Extensions;
@@ -53,7 +54,20 @@ protected override Task AssertOnAllResponses(Action<TResponse> assert)
 					return;
 				}
 
-				assert(r);
+				using (var scope = new AssertionScope())
+				{
+					assert(r);
+					var failures = scope.Discard();
+					if (failures.Length <= 0) return;
+					
+					var failure = failures[0];
+					scope.AddReportable("Failure", failure);
+					scope.AddReportable("DebugInformation", r.DebugInformation);
+					scope.FailWith( $@"{{Failure}}
+Response Under Test:
+{{DebugInformation}}");
+
+				}
 			});
 		}
 	}

src/Tests/Tests/Search/Request/FieldsUsageTests.cs

@@ -60,7 +60,6 @@ [I] protected Task FieldsAreReturned() => this.AssertOnAllResponses(r =>
 				var name = fieldValues.Value<string>(Field<Project>(p => p.Name));
 				name.Should().NotBeNullOrWhiteSpace();
 
-
 				var commits = fieldValues.ValueOf<Project, float?>(p => p.NumberOfCommits);
 				commits.Should().BeGreaterThan(0);