HelpPageMiddlewareExtensions.GetBinPath() causes The path is not of a legal form.

[willemsevenster]

The error is in how the CodeBase value is formatted - it is a Uri rather than a path. The implementation of the GetBinPath() method could perhaps be changed to:
return Path.GetDirectoryName(new Uri(Assembly.GetExecutingAssembly().GetName().CodeBase)?.LocalPath);

or at least to

return Path.GetDirectoryName((Assembly.GetExecutingAssembly().GetName().CodeBase ?? string.Empty).Replace("file:///", string.Empty))

[DalSoft]

Under what conditions are you getting this exception?

The return already does the replace.

var executingAssemblyPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().GetName().CodeBase) ?? string.Empty;
return executingAssemblyPath.Replace("file:\\", string.Empty);

[willemsevenster]

I'm running my project in a self-hosted Owin Web Api project using .Net 4.6.2. After investigating further, in my Owin StartUp class, the call to Assembly.GetExecutingAssembly().GetName() returns "file:///D:/Work/tfs/SPQ.MicroScheduler/SPQ.MicroScheduler.Services.Api/bin/Debug/mschedapisvc.EXE".

If I execute the following in the Immediate Window, I get the The path is not of a legal form exception:
Path.GetDirectoryName("file:///D:/Work/tfs/SPQ.MicroScheduler/SPQ.MicroScheduler.Services.Api/bin/Debug/mschedapisvc.EXE")

If I remove the `file:///' bit at the start, it works fine in the Immediate Window.

If I execute the same instruction above in the C# Interactive window, I do not get the error. This does not seem to be an issue with your code, but rather an anomoly/bug in the .Net framework. My fix above does work in all instances.

[DalSoft]

Sure but doesn't mine:

var executingAssemblyPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().GetName().CodeBase) ?? string.Empty;
return executingAssemblyPath.Replace("file:\\", string.Empty);

And yours ...

return Path.GetDirectoryName((Assembly.GetExecutingAssembly().GetName().CodeBase ?? string.Empty).Replace("file:///", string.Empty))

Do the same thing or am I missing something? Please feel free to re-open if I am.

[willemsevenster]

The difference between the 2 sets of code are that in my code, the file:/// is removed from the path before it is being sent to the Path.GetDirectory() method. This seems to overcome the issue in the framework code.

[DalSoft]

Ok I see what your saying under certain conditions Path.GetDirectory throws before the return. Thank you that makes sense. I'll make the change so that file:// is striped off first.

[willemsevenster]

Thank you, I appreciate it. Thank you also for sharing a great tool.