Do not continue asserting on the concrete exception type when the exception is null (fluentassertions#2398)

* Improved the failure message for `ThrowExactly[Async]`

* Add release notes

Co-authored-by: Jonas Nyrup <[email protected]>

---------

Co-authored-by: IT-VBFK <[email protected]>
Co-authored-by: Jonas Nyrup <[email protected]>

Author: 3 people

Src/FluentAssertions/Specialized/AsyncFunctionAssertions.cs

@@ -138,12 +138,15 @@ public async Task<ExceptionAssertions<TException>> ThrowExactlyAsync<TException>
         {
             Exception exception = await InvokeWithInterceptionAsync(Subject);
 
-            Execute.Assertion
+            success = Execute.Assertion
                 .ForCondition(exception is not null)
                 .BecauseOf(because, becauseArgs)
                 .FailWith("Expected {0}{reason}, but no exception was thrown.", expectedType);
 
-            exception.Should().BeOfType(expectedType, because, becauseArgs);
+            if (success)
+            {
+                exception.Should().BeOfType(expectedType, because, becauseArgs);
+            }
 
             return new ExceptionAssertions<TException>(new[] { exception as TException });
         }

Src/FluentAssertions/Specialized/DelegateAssertions.cs

@@ -140,12 +140,15 @@ public ExceptionAssertions<TException> ThrowExactly<TException>(string because =
 
             Type expectedType = typeof(TException);
 
-            Execute.Assertion
+            success = Execute.Assertion
                 .ForCondition(exception is not null)
                 .BecauseOf(because, becauseArgs)
                 .FailWith("Expected {0}{reason}, but no exception was thrown.", expectedType);
 
-            exception.Should().BeOfType(expectedType, because, becauseArgs);
+            if (success)
+            {
+                exception.Should().BeOfType(expectedType, because, becauseArgs);
+            }
 
             return new ExceptionAssertions<TException>(new[] { exception as TException });
         }

Tests/FluentAssertions.Specs/Specialized/DelegateAssertionSpecs.cs

@@ -1,4 +1,6 @@
 using System;
+using System.Threading.Tasks;
+using FluentAssertions.Execution;
 using FluentAssertions.Specialized;
 using Xunit;
 
@@ -34,4 +36,22 @@ public void When_injecting_a_null_clock_it_should_throw()
         act.Should().ThrowExactly<ArgumentNullException>()
             .WithParameterName("clock");
     }
+
+    public class ThrowExactly
+    {
+        [Fact]
+        public void Does_not_continue_assertion_on_exact_exception_type()
+        {
+            // Arrange
+            var a = () => { };
+
+            // Act
+            using var scope = new AssertionScope();
+            a.Should().ThrowExactly<InvalidOperationException>();
+
+            // Assert
+            scope.Discard().Should().ContainSingle()
+                .Which.Should().Match("*InvalidOperationException*no exception*");
+        }
+    }
 }

Tests/FluentAssertions.Specs/Specialized/TaskAssertionSpecs.cs

@@ -3,6 +3,7 @@
 using System.Threading.Tasks;
 using FluentAssertions.Execution;
 using FluentAssertions.Extensions;
+using FluentAssertions.Specialized;
 using Xunit;
 using Xunit.Sdk;
 
@@ -466,6 +467,24 @@ await action.Should().ThrowAsync<XunitException>().WithMessage(
         }
     }
 
+    public class ThrowExactlyAsync
+    {
+        [Fact]
+        public async Task Does_not_continue_assertion_on_exact_exception_type()
+        {
+            // Arrange
+            var a = () => Task.Delay(1);
+
+            // Act
+            using var scope = new AssertionScope();
+            await a.Should().ThrowExactlyAsync<InvalidOperationException>();
+
+            // Assert
+            scope.Discard().Should().ContainSingle()
+                .Which.Should().Match("*InvalidOperationException*no exception*");
+        }
+    }
+
     [Collection("UIFacts")]
     public class CompleteWithinAsyncUIFacts
     {

docs/_pages/releases.md

@@ -21,6 +21,8 @@ sidebar:
 * Capitalize `true` and `false` in failure messages and make them formattable to a custom `BooleanFormatter` - [#2390](https://github.com/fluentassertions/fluentassertions/pull/2390), [#2393](https://github.com/fluentassertions/fluentassertions/pull/2393)
 * Improved the failure message for `NotBeOfType` when wrapped in an `AssertionScope` and the subject is null  - [#2399](https://github.com/fluentassertions/fluentassertions/pull/2399)
 * Improved the failure message for `BeWritable`/`BeReadable` when wrapped in an `AssertionScope` and the subject is read-only/write-only - [#2399](https://github.com/fluentassertions/fluentassertions/pull/2399)
+* Improved the failure message for `ThrowExactly[Async]` when wrapped in an `AssertionScope` and no exception is thrown - [#2398](https://github.com/fluentassertions/fluentassertions/pull/2398)
+
 
 ## 6.12.0