Blazor .NET 5.0.3 service-worker.published.js broken

[groogiam]

Describe the bug

The service worker defined by service-worker.published.js throws Uncaught (in promise) TypeError: Failed to fetch when running from visual studio.

To Reproduce

See attached repro. Run the project and check the browsers dev console.
PWATest.zip

Note: repro is the exact output that visual studio generate except the service worker path in the index.html has been updated to the production worker.

I cannot get this to work on both
Chrome 88.0.4324.190 and Edge 88.0.705.81

Exceptions (if any)

Further technical details

• ASP.NET Core version
• Include the output of dotnet --info
• Runtime Environment:
  OS Name: Windows
  OS Version: 10.0.19042
  OS Platform: Windows
  RID: win10-x64
  Base Path: C:\Program Files\dotnet\sdk\5.0.103\

Host (useful for support):
Version: 5.0.3
Commit: c636bbdc8a

.NET SDKs installed:
5.0.103 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.All 2.1.25 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.25 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.1.25 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.12 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.3 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.1.12 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.3 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET runtimes or SDKs:
https://aka.ms/dotnet-download

Visual Studio 16.8.6

[mkArtakMSFT]

Thanks for contacting us.
We see many customers hit similar issues and most of those are usually caused by mistakes on their side. Please have a look at these docs to help you with this issue.
If you still face this issue after going through the docs let us know.

[groogiam]

After some more investigation this appears to be related to what looks like a bug in the service-worker-assets.js generation. Whatever msbuild logic is creating this js file seems to always add the blazor css isolation files {asm}.bundle.scp.css and {asm}.styles.css even if these files are not generated in the output. This causes the await caches.open(cacheName).then(cache => cache.addAll(assetsRequests)); line in the service worker to fail as the missing assets on the server result in a 404.

Thanks for contacting us.
We're moving this issue to the Next sprint planning milestone for future evaluation / consideration. We will evaluate the request when we are planning the work for the next milestone. To learn more about what to expect next and how this issue will be handled you can read more about our triage process here.

[javiercn]

@groogiam thanks for the additional details.

This seems like a bug then.