fix: Address issue with FeatureClient not being resolved when no Provider added

[kylejuliandev]

This PR

This PR fixes an issue when configuring OpenFeature without a Provider. The singleton approach provided by Api.Instance can handle this scenario, so the Dependency Injection approach should be able to. Take the following:

var builder = WebApplication.CreateSlimBuilder(args);

builder.Services.AddOpenFeature(featureBuilder =>
{
    featureBuilder
        .AddContext(dict => dict.Set("region", "euw"));
});

var app = builder.Build();

app.MapGet("/welcome", async ([FromServices] IFeatureClient featureClient) =>
{
    var welcomeMessageEnabled = await featureClient.GetBooleanValueAsync("welcome-message", false);

    if (welcomeMessageEnabled)
    {
        return TypedResults.Ok("Hello world! The welcome-message feature flag was enabled!");
    }

    return TypedResults.Ok("Hello world!");
});

app.Run();

When you run this and try to send a request to GET /welcome you will get an error trying to resolve IFeatureClient. This only manifests at runtime.

Related Issues

Fixes #544

Notes

Follow-up Tasks

How to test

[kylejuliandev]

Blocked by #606

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.85%. Comparing base (c987b58) to head (123f4e8).
⚠️ Report is 7 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #607   +/-   ##
=======================================
  Coverage   89.84%   89.85%           
=======================================
  Files          77       77           
  Lines        3162     3163    +1     
  Branches      364      364           
=======================================
+ Hits         2841     2842    +1     
  Misses        251      251           
  Partials       70       70           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[kylejuliandev]

/gemini review

[gemini-code-assist]

Code Review

This pull request effectively resolves a runtime error that occurred when trying to resolve IFeatureClient via dependency injection without any feature providers configured. The fix involves two key changes: ensuring OpenFeatureOptions is always registered in the service collection, and using FirstOrDefault() instead of First() to safely handle cases with no provider names. A new test case has also been added to validate this fix. The changes are correct and well-implemented. I have one minor suggestion to improve code clarity.

[askpt]

Thanks for the PR. I wonder what is the impact of that change.