Supporting both .Net Core and .Net Framework in one process.

[DmitrySyrkin]

Good morning, everyone.
First of all, thanks to @agracio for the work he is doing.

My question is as follows:
we are using edge-js with Specflow tests and now are are switching our backend API from .Net Framework 4.8 to .Net 8.0.
The main issue, as far as I understand, that prevents me to use edge-cs for both new and old versions of API is having all settings as environment variables. For example, EDGE_APP_ROOT should be empty in case of .net framework and should be set for .net core.

I can imagine rebuilding edge-js from source code with settings renaming (like EDGE_CORE_APP_ROOT) and referencing two version of package, but, not sure it is a great idea.

If anyone can share thoughts\experience, I'd really appreciate that.

Thank you.
Dmitry Syrkin

[agracio]

This is actually not an issue when switching between .NET Core and .NET Framework. You can always set EDGE_APP_ROOT variable but .NET Framework ignores it, you can see this use case in tools/test.js.

However when switching between .NET Core and .NET Standard it is important to NOT set EDGE_APP_ROOT for .NET Standard. You can see that in https://github.com/agracio/edge-js-quick-start main.js. But if you have such a use case then consider sending runtime parameters to your process.

[agracio]

Another important thing to clarify is usage of different .NET flavours in one process as you put it in the title of this discussion. It is not possible to switch between .NET Framework and .NET Core during the process lifetime once Edge.Js is loaded.

For example setting EDGE_USE_CORECLR=1 running some code and then setting EDGE_USE_CORECLR=undefined programmatically from within the running application then trying to run some code will lead to unexpected Edge.js errors for second .NET flavour.

This does not mean that EDGE_USE_CORECLR variable has to be specified via command line, but when running .NET Core application it needs to be set before executing 'const edge = require('edge-js');'.

process.env.EDGE_USE_CORECLR = 1;
const edge = require('edge-js');

[DmitrySyrkin]

Thank you very much for quick response. I've rechecked if we used netstandard, but looks like you've spotted the real problem in your comment. So, for now I see two possibilities: 1) try to rebuild your project with different env settings names or 2) try to migrate our application to .net core.

[agracio]

Not sure if I understand your reply correctly, if you use .NET Standard then you don't need to set EDGE_APP_ROOT parameter at all.
And if you use .NET Core then you can set EDGE_APP_ROOT and it will be ignored by .NET Framework and only used by .NET Core.
I don't see what benefit you can get from adding extra parameter in Edge.Js.

Here is an explanation of EDGE_APP_ROOT usage.

Framework	EDGE_APP_ROOT Impact
.NET 4.x	Ignored, can be set to anything
.NET Core	Required if dll paths are not absolute
.NET Standard	Should NOT be set

[agracio]

Let me know if the comment above clarifies your question.

[DmitrySyrkin]

Thank you very much for clarifications. We have some netstandard libraries in a solution, but the one we use for edge-js is on .net framework (that's why I was a bit confused).
My current understanding is that not EDGE_APP_ROOT is the issue but EDGE_USE_CORECLR itself. And we cannot set it to 1 and use with both .net8 and net48 projects in same process (e.g. because of using HttpContext from System.Web). I'll try to discuss with the team if migration to net8 can be done.
Please let me know if I'm missing anything again and thank you for your time and support.

[agracio]

You can run .NET Core and .NET Standard applications without setting EDGE_USE_CORECLR variable.
Take https://github.com/agracio/edge-js-quick-start as an example, it will run in both Core and Standard mode even if EDGE_USE_CORECLR not set, the underlying code will default to using .NET Framework execution and the code will run just fine.

Also while testing different variations of the code I discovered that EDGE_APP_ROOT is not actually required if your specify absolute paths to dlls that you are using.
For example in https://github.com/agracio/edge-js-quick-start I specify absolute paths to baseDll parameters in each method , in this case EDGE_APP_ROOT is not required.

var getAppDomainDirectory = edge.func({
    assemblyFile: baseDll,
    typeName: localTypeName,
    methodName: 'GetAppDomainDirectory'
});

But in edge-js tests EDGE_APP_ROOT is set while assemblyFile is passed a name test without .dll extension. This tell Edje.Js to look for that assembly in the specified root.

[DmitrySyrkin]

I think that when I tried to load net8.0 assembly without CORECLR flag set, I was getting
Could not load file or assembly 'System.Runtime, Version=8.0.0.0,

I'll recheck with quick-start project and will let you know. Thank you!