如何在catch块中获取Assert.Multiple的完整断言失败报告？

Great question! When you catch a MultipleAssertException and just call ToString() on it, you only get a condensed summary—but NUnit actually stores all the detailed failure details directly in the exception object. Here's how you can extract the full, report-like error message:

Step 1: Cast the exception to MultipleAssertException #

First, since you know the exception thrown from Assert.Multiple is a MultipleAssertException, you can safely cast it to that type to access its special properties (no need for generic Exception unless you're handling other error types too).

Step 2: Access the Results property #

This exception has a Results property that holds a list of AssertionResult objects—each one represents a single failed assertion in your multiple block. Every AssertionResult includes the full failure message exactly as it appears in the test report.

Modified Code Example #

Here's how to update your test method to capture the full failure details:

[Test]
public void AssertMultipleTest()
{
    try
    {
        Assert.Multiple(() =>
        {
            Assert.That(true, Is.False);
            Assert.That(7, Is.Zero);
        });
    }
    catch (MultipleAssertException multiEx)
    {
        // Build the full error message that matches the test report format
        var fullErrorMessage = new StringBuilder("One or more failures in Multiple Assert block:");
        for (int i = 0; i < multiEx.Results.Count; i++)
        {
            fullErrorMessage.AppendLine($"\n{i + 1}) {multiEx.Results[i].Message}");
        }
        
        // Log the complete message
        Log.Save(fullErrorMessage.ToString());
        
        // Re-throw the original exception to preserve test failure behavior
        throw;
    }
}

Bonus: Handle General Exceptions #

If you need to catch all exceptions (not just MultipleAssertException), you can add a check for the exception type:

catch (Exception e)
{
    if (e is MultipleAssertException multiEx)
    {
        // Build full message as shown above
        var fullErrorMessage = new StringBuilder("One or more failures in Multiple Assert block:");
        for (int i = 0; i < multiEx.Results.Count; i++)
        {
            fullErrorMessage.AppendLine($"\n{i + 1}) {multiEx.Results[i].Message}");
        }
        Log.Save(fullErrorMessage.ToString());
    }
    else
    {
        // Handle non-multiple assertion exceptions normally
        Log.Save(e.ToString());
    }
    throw;
}

You can also access multiEx.Results[i].StackTrace if you need to capture the stack trace for each individual failed assertion, though the test report usually focuses on the message itself.

内容的提问来源于stack exchange，提问作者Iceeman