RazorLight not working in single-file bundle

[afucher]

Describe the bug
I'm trying to use this package but when I publish using -p:PublishSingleFile=true, my application throws an error when the code touch this library.

To Reproduce
Steps to reproduce the behavior:

1. Build a project using RazorLight
2. Publish the project using the argument -p:PublishSingleFile=true, for example: dotnet publish . -c Release -r win-x64 -p:PublishSingleFile=true
3. Run the project, and make the application run the specific part that use RazorLight

Expected behavior
I expected that my application works.

fail: Microsoft.AspNetCore.Server.Kestrel[13]
      Connection id "0HM6E5ELP1500", Request id "0HM6E5ELP1500:00000002": An unhandled exception was thrown by the application.
      System.NotSupportedException: CodeBase is not supported on assemblies loaded from a single-file bundle.
         at System.Reflection.RuntimeAssembly.get_CodeBase()
         at Microsoft.Extensions.DependencyModel.DependencyContextLoader.GetNormalizedCodeBasePath(Assembly assembly)
         at Microsoft.Extensions.DependencyModel.DependencyContextLoader.GetDepsJsonPath(Assembly assembly)
         at Microsoft.Extensions.DependencyModel.DependencyContextLoader.LoadAssemblyContext(Assembly assembly, IDependencyContextReader reader)
         at Microsoft.Extensions.DependencyModel.DependencyContextLoader.Load(Assembly assembly)
         at Microsoft.Extensions.DependencyModel.DependencyContext.Load(Assembly assembly)
         at RazorLight.Compilation.RoslynCompilationService.GetDependencyContextCompilationOptions()
         at RazorLight.Compilation.RoslynCompilationService.EnsureOptions()
         at RazorLight.Compilation.RoslynCompilationService.get_ParseOptions()
         at RazorLight.Compilation.RoslynCompilationService.CreateSyntaxTree(SourceText sourceText)
         at RazorLight.Compilation.RoslynCompilationService.CreateCompilation(String compilationContent, String assemblyName)
         at RazorLight.Compilation.RoslynCompilationService.CompileAndEmit(IGeneratedRazorTemplate razorTemplate)
         at RazorLight.Compilation.RazorTemplateCompiler.CompileAndEmit(RazorLightProjectItem projectItem)
         at RazorLight.Compilation.RazorTemplateCompiler.OnCacheMissAsync(String templateKey)
      --- End of stack trace from previous location ---
         at RazorLight.EngineHandler.CompileTemplateAsync(String key)
         at RazorLight.EngineHandler.CompileRenderAsync[T](String key, T model, ExpandoObject viewBag)
         at aera_core.Controllers.DownloadController.geraLista(Int32 id)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.TaskOfIActionResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)

Information (please complete the following information):

• OS: Windows 10
• Platform .NET 5.0.100
• RazorLight version 2.0.0-rc.3
• Are you using the OFFICIAL RazorLight package? Yes
• Visual Studio version: N/A, I'm using Rider.

Additional context

[marcosdimitrio]

I experienced the same problem but with a different error message.

Everything works fine locally, but when I publish it I get:

RazorLight: Can't load metadata reference from the entry assembly. Make sure 
PreserveCompilationContext is set to true in *.csproj file

Stack trace:
at RazorLight.Compilation.DefaultMetadataReferenceManager.Resolve(Assembly assembly, DependencyContext dependencyContext)
at RazorLight.Compilation.DefaultMetadataReferenceManager.Resolve(Assembly assembly)
at RazorLight.Compilation.RoslynCompilationService.EnsureOptions()
at RazorLight.Compilation.RoslynCompilationService.get_ParseOptions()
at RazorLight.Compilation.RoslynCompilationService.CreateSyntaxTree(SourceText sourceText)
at RazorLight.Compilation.RoslynCompilationService.CreateCompilation(String compilationContent, String assemblyName)
at RazorLight.Compilation.RoslynCompilationService.CompileAndEmit(IGeneratedRazorTemplate razorTemplate)
at RazorLight.Compilation.RazorTemplateCompiler.CompileAndEmit(RazorLightProjectItem projectItem)
at RazorLight.Compilation.RazorTemplateCompiler.OnCacheMissAsync(String templateKey)
--- End of stack trace from previous location ---
at RazorLight.EngineHandler.CompileTemplateAsync(String key)
at RazorLight.EngineHandler.CompileRenderAsync[T](String key, T model, ExpandoObject viewBag)
at MyApplication.MyTemplateParser.CompileAsync(TemplateDto templateDto)
...

If I set PublishSingleFile to False in the Publish Profile, then the error disappears:

<?xml version="1.0" encoding="utf-8"?>
<!--
https://go.microsoft.com/fwlink/?LinkID=208121. 
-->
<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    ...
    <PublishSingleFile>False</PublishSingleFile>
    ...
  </PropertyGroup>
</Project>

Additional information

• OS: Windows Server 2012, IIS version 8.5
• Platform .NET 5.0
• RazorLight version 2.0.0-rc.3
• Are you using the OFFICIAL RazorLight package? Yes
• Visual Studio version: Professional 2019 version 16.8.1.

[b0wter]

This also happens to me on linux (Ubuntu 20.04).

[b0wter]

I experienced the same problem but with a different error message.

Everything works fine locally, but when I publish it I get:

RazorLight: Can't load metadata reference from the entry assembly. Make sure 
PreserveCompilationContext is set to true in *.csproj file

Stack trace:
at RazorLight.Compilation.DefaultMetadataReferenceManager.Resolve(Assembly assembly, DependencyContext dependencyContext)
at RazorLight.Compilation.DefaultMetadataReferenceManager.Resolve(Assembly assembly)
at RazorLight.Compilation.RoslynCompilationService.EnsureOptions()
at RazorLight.Compilation.RoslynCompilationService.get_ParseOptions()
at RazorLight.Compilation.RoslynCompilationService.CreateSyntaxTree(SourceText sourceText)
at RazorLight.Compilation.RoslynCompilationService.CreateCompilation(String compilationContent, String assemblyName)
at RazorLight.Compilation.RoslynCompilationService.CompileAndEmit(IGeneratedRazorTemplate razorTemplate)
at RazorLight.Compilation.RazorTemplateCompiler.CompileAndEmit(RazorLightProjectItem projectItem)
at RazorLight.Compilation.RazorTemplateCompiler.OnCacheMissAsync(String templateKey)
--- End of stack trace from previous location ---
at RazorLight.EngineHandler.CompileTemplateAsync(String key)
at RazorLight.EngineHandler.CompileRenderAsync[T](String key, T model, ExpandoObject viewBag)
at MyApplication.MyTemplateParser.CompileAsync(TemplateDto templateDto)
...

If I set PublishSingleFile to False in the Publish Profile, then the error disappears:

<?xml version="1.0" encoding="utf-8"?>
<!--
https://go.microsoft.com/fwlink/?LinkID=208121. 
-->
<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    ...
    <PublishSingleFile>False</PublishSingleFile>
    ...
  </PropertyGroup>
</Project>

Additional information

* OS: Windows Server 2012, IIS version 8.5

* Platform .NET 5.0

* RazorLight version 2.0.0-rc.3

* Are you using the OFFICIAL RazorLight package? Yes

* Visual Studio version: Professional 2019 version 16.8.1.

@marcosdimitrio :
You need to add the following into a <PropertyGroup> your csproj-file:

<PreserveCompilationContext>true</PreserveCompilationContext>

Unfortunately that will not help you fix all errors but the one you're currently encountering.
See this for details.

[b0wter]

I've done some more digging an am not sure that there is anything this project can do.

RazorLight.Compilation.RoslynCompilationService.GetDependencyContextCompilationOptions

calls

Microsoft.Extensions.DependencyModel.DependencyContext.Load

which calls

Microsoft.Extensions.DependencyModel.DependencyContextLoader.GetDepsJsonPath

That method calls

string assemblyLocation = assembly.Location;

which will always set null because there is no meaningful value to set in a single-file bundle as it can no longer point to a filename.
(See the file here)
Since no valid value is set the code falls back to calling assembly.CodeBase which suffers the same problem but will raise an exception instead of returning null.

[marcosdimitrio]

@marcosdimitrio :
You need to add the following into a <PropertyGroup> your csproj-file:

<PreserveCompilationContext>true</PreserveCompilationContext>

Unfortunately that will not help you fix all errors but the one you're currently encountering.
See this for details.

I did include it in both projects (webapi and razorlight project), it only worked when PublishSingleFile is set to false. When I set PublishSingleFile to true it stops working.

[toddams]

RazorLight indeed does not work in a single-file bundle yet.
This is relatively new feature and nobody did any work to support that. But it should be supported, imo

[toddams]

dotnet/runtime#35493

[FLAMESpl]

Hi @toddams, is there any work going on in the matter of supporting single-file bundles?

[akhanalcs]

Any update on this? I'm affected by this issue.