404 Errors for all assets in Test Server – Unable to load assets and check UI tests

[Cyrus-Sushiant]

Is there an existing issue for this?

• [X] I have searched the existing issues

Describe the bug

I'm encountering an issue when trying to open the test server app in the browser. Some assets (e.g., CSS, JS, images, etc.) are returning 404 errors, which prevents the application from loading correctly.

As a result, the app does not display with full functionality, and I am unable to properly check the UI for testing purposes. This issue makes it difficult to run effective UI tests.

Expected Behavior

The assets should load correctly, allowing the app to display and function as expected to proceed with UI testing.

Steps To Reproduce

Example steps:

1. Clone my repo at https://github.com/Cyrus-Sushiant/PlaywrightIssue
2. Run the GotoCounterPage test in the MyTest class in the tests project
3. Open http://127.0.0.1:2001 in your browser
4. Some assets (e.g., CSS, JS, images, etc.) are returning 404 errors, which prevents the application from loading correctly.

Exceptions (if any)

No response

.NET Version

8.0.401

Anything else?

No response

[javiercn]

@Cyrus-Sushiant thanks for contacting us.

That likely is caused by you running the build output in Production without explicitly setting up static web assets.

Static Web Assets are only loaded in Developmnet environment. You need to call StaticWebAssetsLoader.UseStaticWebAssets if you are not running in development.

[ysmoradi]

The environment has been set to development, so I assume calling StaticWebAssetsLoader.UseStaticWebAssets is not required (Even though I called it without success)

Note that if we set Sdk of test project to Microsoft.NET.Sdk.Web the staticwebassets.development.json file gets generated, but for some reason, aspnetcore doesn't use it.

[Cyrus-Sushiant]

As @ysmoradi said, the environment has been set to development. You can see in this class: https://github.com/Cyrus-Sushiant/PlaywrightIssue/blob/master/PlaywrightIssue.Tests/MyTest.cs

[javiercn]

@ysmoradi You need to call this one StaticWebAssetsLoader.UseStaticWebAssets(builder.Environment, builder.Configuration); not the one you called.

You also need to pass in the file to load, since otherwise is going to try and load the one from the test project, not the one from your host project.

You have all the logic https://github.com/dotnet/aspnetcore/blob/main/src/Hosting/Hosting/src/StaticWebAssets/StaticWebAssetsLoader.cs

[dotnet-policy-service[bot]]

Hi @Cyrus-Sushiant. We have added the "Needs: Author Feedback" label to this issue, which indicates that we have an open question for you before we can take further action. This issue will be closed automatically in 7 days if we do not hear back from you by then - please feel free to re-open it if you come back to this issue after that time.

[ysmoradi]

Thanks for your efforts, I really appreciate it. Two notes to consider:

1- Changing test project sdk to Microsoft.NET.Sdk.Web will result into generating all required files such as staticwebassets.development.json, so we don't have to look for these files in host project (aspnetcore project)

2- Event though calling StaticWebAssetsLoader.UseStaticWebAssets(builder.Environment, builder.Configuration); is not required if dev environment, but even if you call it, it won't work! you can easily test that in the sample source code.

[ysmoradi]

The builder.Environment.ApplicationName is testhost (for the builder that is being built in mstest method) Assigning appropriate ApplicationName resolved the issue

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