Wasm size is increasing in .Net 9

[gfoidl]

Discussed in dotnet/aspnetcore#58914

^{Originally posted by codemahek November 13, 2024}

Today I migrated one of my project from .Net 8 to .Net 9 and to my surprise wasm size of almost all of them has increased compared to .net 8 and especially MudBlazor was worst with 9.1 mb.
Is it because it’s not yet compiled with .net 9 or it’s a regression from asp.net

[javiercn]

@gfoidl thanks for contacting us.

Is that the deployed app?

Is it being served with compression?

[halter73]

Also, what size did you see for the MudBlazor assembly in .NET 8?

@lewing Could this have been caused by mono changes?

[gfoidl]

@javiercn it's not me that sees the size increase, I just "moderated" from the discussion to the issue here.

@codemahek please see the comments above.

[codemahek]

Apologies, I forgot to mention that I had deployed it as Debug and not release. But still even in Debug mode .Net 8 wasm is smaller than .Net 9 Which seems unusual.

[codemahek]

I think the main culprit is "app.MapStaticAssets()". If I use that suddenly the size is increased and if I revert it back to "app.UseStaticFiles()" everything looks good and even the size is very small.

[ScarletKuro]

Apologies, I forgot to mention that I had deployed it as Debug and not release. But still even in Debug mode .Net 8 wasm is smaller than .Net 9 Which seems unusual.

A few questions:

1. Why are you deploying in "Debug" mode? FYI, trimming doesn't work for assemblies compiled in Debug mode. It only works when you publish.
2. What was the size on .NET 8?

The thing is, the untrimmed full size of MudBlazor is exactly 9.1 MB, which matches the one in your screenshot. So, it would be odd if you had a smaller size in .NET 8, especially considering you're deploying in Debug mode.

You really scared me with the issues. I thought MSFT had broken trimming. However, I couldn't reproduce the problem. After publishing, the size reduced from 9.1 MB to 550 KB (using NET9 SDK).

[codemahek]

Apologies for that. I deployed on Debug mode by mistake.
Since I am new to Blazor so please bear with me about my understanding.
I thought even in Debug mode both .net 8 and .net 9 should produce the same size but things change when you replace "app.UseStaticFiles()" to "app.MapStaticAssets()"

[gfoidl]

in Debug mode both .net 8 and .net 9 should produce the same size but things change when you replace "app.UseStaticFiles()" to "app.MapStaticAssets()"

But in Release it's not a problem?

If so, can we close this issue?