Default Blazor Wasm template managed libraries size reduction

[marek-safar]

There is a lot of unnecessary assemblies left in the default Blazor Wasm template after trimming.

The list of assemblies which should be easy to fully eliminate

• System.Collections.Concurrent.dll - It has no use in single threaded environment
• System.Collections.Immutable.dll - It does not seem to be needed at all Remove System.Text.Json's DynamicDependencies on Collections.Immutable runtime#53317
• System.ComponentModel.dll - Single interface method is used from it
• System.Console.dll - Remove dependency on System.Console in default Blazor WASM app #31148
• System.IO.Pipelines Blazor WASM app leaves untrimmed System.IO.Pipelines assembly by default #27782
• System.Linq.dll - It should be possible to remove most if not all use of it
• System.ObjectModel.dll - Change Router _emptyParametersDictionary to a regular Dictionary #31460
• System.Private.Uri.dll - Only System.Uri::.ctor(string) is needed
• System.Runtime.CompilerServices.Unsafe.dll Typeforward System.Runtime.CompilerServices.Unsafe to SPC for netcore runtime#45475
• System.Text.Encodings.Web.dll - Single use to create JsonEncodedText from hardcoded string constant
• Microsoft.Extensions.Logging.Abstractions.dll Add option to disable logging in sample Blazor app #27721
• Microsoft.Extensions.Logging.dll Add option to disable logging in sample Blazor app #27721

Cleaning this up could reduce the trimmed output for managed libraries for the default template by ~15%

@eerhardt @lewing @SamMonoRT

[javiercn]

@marek-safar thanks for doing this investigation.

There are indeed some low-hanging fruits here.

For the logging assemblies, is the linker smart enough to remove the callsites from other assemblies if we tell it to remove the entire library?

[marek-safar]

Yes, if you remove the need for the dependency the linker will update the code not to require the assembly at all.

[eerhardt]

System.Collections.Concurrent.dll - It has no use in single threaded environment
System.Collections.Immutable.dll - It does not seem to be needed at all

I believe these are being rooted by System.Text.Json, and will be removed with the source generator work. (With the exception of ConcurrentDictionary, since ASP.NET and Microsoft.Extensions reference it in many places.)

cc @tannergooding - who is working on enabling the STJ source generator for Blazor WASM.

System.ComponentModel.dll - Single interface method is used from it

But that single interface is pretty important - IServiceProvider. You can't do DependencyInjection without it.

[eerhardt]

System.Text.Encodings.Web.dll - Single use to create JsonEncodedText from hardcoded string constant

I'm not understanding this comment. I see this assembly used to do escaping of property names and strings in System.Text.Json:

For example:

• https://github.com/dotnet/runtime/blob/8a52f1e948b6f22f418817ec1068f07b8dae2aa5/src/libraries/System.Text.Json/src/System/Text/Json/Writer/JsonWriterHelper.Escaping.cs#L56-L59
• https://github.com/dotnet/runtime/blob/8a52f1e948b6f22f418817ec1068f07b8dae2aa5/src/libraries/System.Text.Json/src/System/Text/Json/Writer/JsonWriterHelper.Escaping.cs#L138-L142

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[marek-safar]

System.Collections.Concurrent

This is primary Blazor report. This type is used at several places with no good reason for WebAssembly.

But that single interface is pretty important - IServiceProvider. You can't do DependencyInjection without it.

Do we need to do dependency injection in the default template? If it's really that important should we have an assembly with a single used method?

I'm not understanding this comment. I see this assembly used to do escaping of property names and strings in System.Text.Json:

This is primary Blazor size report. I didn't want to mix it with problems in STJ and will probably file a separate issue about it.