[mbr] hot reload doesn't work on lambda bodies

[SteveSandersonMS]

Description

The hot reload feature seems to work a lot better on Index.razor than on certain other files. I'm not sure why the behavior differs.

Steps:

• Use latest preview 3 SDK
• dotnet new blazorwasm -o MyApp
• cd MyApp
• dotnet watch
• When the app is running, modify some text in Pages/Index.razor - see it appears correctly in the browser
• Now try a similar edit inside Shared/NavMenu.razor, for example change the text Home to Home2.
  • Expected: change is applied
  • Actual: runtime crashes

Configuration

This is with SDK 6.0.100-preview.3.21173.6, with Microsoft.NETCoreSdk.BundledVersions.props patched to use the runtime version 6.0.0-preview.4.21174.4.

cc @lambdageek

Tagging subscribers to 'arch-wasm': @lewing
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

The hot reload feature seems to work a lot better on Index.razor than on certain other files. I'm not sure why the behavior differs.

Steps:

• Use latest preview 3 SDK
• dotnet new blazorwasm -o MyApp
• cd MyApp
• dotnet watch
• When the app is running, modify some text in Pages/Index.razor - see it appears correctly in the browser
• Now try a similar edit inside Shared/NavMenu.razor, for example change the text Home to Home2.
  • Expected: change is applied
  • Actual: runtime crashes

Configuration

This is with SDK 6.0.100-preview.3.21173.6, with Microsoft.NETCoreSdk.BundledVersions.props patched to use the runtime version 6.0.0-preview.4.21174.4.

cc @lambdageek

Author:	SteveSandersonMS
Assignees:	-
Labels:	arch-wasm
Milestone:	-

[SteveSandersonMS]

@lambdageek I've no idea if this is also addressed by #50248 but thought it best to report it rather than waiting to see.

[lambdageek]

@SteveSandersonMS doesn't look like it's the same thing.

@SteveSandersonMS when reporting these, one thing that would be super helpful:

1. Save the baseline .dll
2. Open a JS console and put a breakpoint in aspnetcore-browser-refresh.js in the applyBlazorDeltas function inside the foreach.
3. When it hits the breakpoint, in the console display the values of d.metadataDelta and d.ilDelta and save them. (please make sure that the JS console isn't eliding the middle with "...")
4. hit Continue in the JS debugger and repeat for any other deltas.

[lambdageek]

The body of the NavLink component is a RenderFragment lambda, and changing "Home" => "Home2" is updating the lambda body. It's emitting new fields and methods on the lambda, which Mono MBR doesn't support yet. (ie this is a rude edit - but we need dotnet/roslyn#49010 in order to signal it)

(Update, just for my info)
The decompiled relevant part of NavMenu::BuildRenderTree body before the update is:

			__builder.OpenComponent<NavLink>(20);
			__builder.AddAttribute(21, "class", "nav-link");
			__builder.AddAttribute(22, "href", "");
			__builder.AddAttribute(23, "Match", Microsoft.AspNetCore.Components.CompilerServices.RuntimeHelpers.TypeCheck(NavLinkMatch.All));
			__builder.AddAttribute(24, "ChildContent", (RenderFragment)delegate(RenderTreeBuilder __builder2)
			{
				__builder2.AddMarkupContent(25, "<span class=\"oi oi-home\" aria-hidden=\"true\" b-zgi052wrvj></span> Home\r\n            ");
			});
			__builder.CloseComponent();

---

Update
So really this is an issue about supporting updates of lambdas. Which we should do. But we're not there yet

Tagging subscribers to this area: @CoffeeFlux
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

The hot reload feature seems to work a lot better on Index.razor than on certain other files. I'm not sure why the behavior differs.

Steps:

• Use latest preview 3 SDK
• dotnet new blazorwasm -o MyApp
• cd MyApp
• dotnet watch
• When the app is running, modify some text in Pages/Index.razor - see it appears correctly in the browser
• Now try a similar edit inside Shared/NavMenu.razor, for example change the text Home to Home2.
  • Expected: change is applied
  • Actual: runtime crashes

Configuration

This is with SDK 6.0.100-preview.3.21173.6, with Microsoft.NETCoreSdk.BundledVersions.props patched to use the runtime version 6.0.0-preview.4.21174.4.

cc @lambdageek

Author:	SteveSandersonMS
Assignees:	lambdageek
Labels:	arch-wasm, area-VM-meta-mono
Milestone:	6.0.0