How to get started and addressing misconceptions

[Joseph-Steven-S]

Hey, I new to MrAdvice. I tried to my best to go through a lot of the example projects that are available but I still am not able to get an Advice up and running. I made to projects both targeting .Net 8.0. One project is a class library with the MrAspect NuGet package and the other is a test project where reference the first project and attempt to use it in a test class.

Is there something I am missing some build tasks that I have to configure to get this working?

In Project 1;

public class LogMethodExecutionAttribute: Attribute, IMethodAdvice 
{
    public static long ElapsedMilliseconds { get; private set; }
    public void Advise(MethodAdviceContext context)
    {
        var stopWatch = System.Diagnostics.Stopwatch.StartNew();
        Console.WriteLine($"Method {context.TargetMethod.Name} is called");
        context.Proceed();
        Console.WriteLine($"Method {context.TargetMethod.Name} is finished");
        stopWatch.Stop();
        Console.WriteLine($"Method {context.TargetMethod.Name} took {stopWatch.ElapsedMilliseconds} ms");
        ElapsedMilliseconds = stopWatch.ElapsedMilliseconds;
    }
}

Test Project 2:
    using ProjectOne.Advices

    [TestClass]
    public class LogMethodExecutionTest
    {

        [TestMethod]
        public void TestAdvice()
        {
            var testClass = new TestClass();
            testClass.TestMethod();
            Console.WriteLine(LogMethodExecutionAttribute.ElapsedMilliseconds);
        }
    }

    public class TestClass
    {
        [LogMethodExecution]
        public void TestMethod()
        {
            var methodInfo = this.GetType().GetMethod("TestMethod");
            Console.WriteLine(methodInfo?.Name);
            var methodBody = methodInfo?.GetMethodBody();
            Console.WriteLine(methodBody?.GetILAsByteArray()?.Length);
            // simulating expensive work
            Task.Delay(2000);
        }
    }

[Joseph-Steven-S]

I would also be happy to take what I learn from this and create documentation for it for future newcomers like myself. Thank you!

[picrap]

Hi Joseph,

you need to weave the project that uses advices, in your case the Test Project 2 also requires the package.
MrAdvice comes as a post-build step, it changes the compiled code to insert hook calls.

Pascal.

[Joseph-Steven-S]

But wouldn't the MrAdvice package on the class library be accessible to the Test project 2? At least, this is what I intuitively understand unless the package reference to MrAdvice in the class project was a private asset. Does it have to do with the Targeting framework(s)?

Thank you! I will give it a try, and hopefully, it will work!

[picrap]

No it’s just a post-build step requirement, that the nuget package adds. The advice must be injected where you use it, not where you declare it.

[Joseph-Steven-S]

Makes sense. I was able to get it running! Thank you so much!

[Joseph-Steven-S]

I have another question, is it possible to introduce attributes on properties, classes or methods using an Advice? And if so how would one do that? Is it possible to do so? I tried going through the examples but I could not find a used example

Thank you again!

[picrap]

Unfortunately, no.

[Joseph-Steven-S]

Hey @picrap , I hope you're doing well. I'm having trouble building MrAdvice on my Linux machine. There was an issue related to this, but it's been resolved. However, I'm still getting errors. I could share the mistakes with you, but I'm also wondering if there might be something I need to configure, like a custom build task.

Or could it be because I set the package reference to the consuming project to PrivateAssets="All"?

Thanks again!

[Joseph-Steven-S]

Unhandled exception: dnlib.DotNet.Writer.ModuleWriterException: Expected a null constant.

Linux only?

If you run into this error while building your project on linux I suggest you do the following to find the issue:

MrAdvice Build Failure on Linux: Decimal Constant Issue (Summary of this)

• .Net Target Framework (net8.0)

Problem Description

• MrAdvice build task fails on Linux (Debian) but works on Windows
• Error occurs during assembly loading/processing in the test project

Debugging Process

1. Commented out all references except MrAdvice in the test project

   • Build succeeded on Linux
   • Windows build unaffected, works with all references

2. Gradually re-added references and files

   • Identified problematic file referencing Project 1 code

3. Isolated specific line causing the issue:

   const decimal price = 0.01m;

Solution

Changing the declaration to either of these forms resolves the issue:

• var price = 0.01m;
• decimal price = 0.01m;

Observations

• Issue specific to Linux (Debian)
• Windows builds unaffected
• Only occurs with const decimal declaration using a literal value

Request for Insight

If anyone can explain why this difference occurs between Linux and Windows platforms when using MrAdvice, please share your knowledge.

Conclusion

This workaround may help others encountering similar issues with MrAdvice on Linux platforms. Further investigation into the root cause would be beneficial for the community.

[picrap]

I am not sure I will be able to fex this. We use a library named dnlib. I’ll update it and produce new versions of Mr Advice. I’ll let you know on this thread. Congratulations for your patience and the accuracy of your report.

[Joseph-Steven-S]

Thank you! You have done a fantastic job already. My patience is respect to your work

[picrap]

I just checked, and unfortunately, dnlib is up to date.

[Joseph-Steven-S]

It must be something else. But thank you again