[Curllog (curllog)]

Register core output caching services in Redis output cache integration

Fixes #21221

Problem

On .NET 11, an app that uses Aspire's Redis output caching together with app.UseOutputCache() crashes at startup:

System.InvalidOperationException: Unable to resolve service for type
'Microsoft.AspNetCore.OutputCaching.IOutputCachePolicyProvider' while attempting to activate
'Microsoft.AspNetCore.OutputCaching.OutputCacheMiddleware'.

This affects the Aspire Starter template's Web frontend as soon as it targets net11.0.

AddRedisOutputCache, AddKeyedRedisOutputCache and AddRedisClientBuilder(...).WithOutputCache() only registered the Redis IOutputCacheStore (through AddStackExchangeRedisOutputCache). They never called AddOutputCache(). In .NET 11, OutputCacheMiddleware requires IOutputCachePolicyProvider, which only AddOutputCache() registers, so the middleware can't be created.

Fix

AddRedisOutputCacheCore, which all three public APIs call, now calls builder.Services.AddOutputCache() before registering the Redis store.

• Calling it twice is harmless: AddOutputCache() uses TryAdd*, so apps that already call it themselves are unaffected.
• The Redis store is still used: AddOutputCache() registers its in-memory IOutputCacheStore with TryAdd, so it doesn't replace the Redis store. The existing AddsRedis*OutputCacheCorrectly tests still pass and check this.
• Works on .NET 8, 9 and 10: AddOutputCache() exists on all supported TFMs. No public API changes.

Tests

I added RegistersOutputCachePolicyProvider to AspireRedisOutputCacheExtensionsTests.cs, a [Theory] that covers all three entry points (plain, keyed, builder). Each case checks that IOutputCachePolicyProvider is registered.

The test is wrapped in #if NET11_0_OR_GREATER, because IOutputCachePolicyProvider doesn't exist before .NET 11. The repo already uses the same pattern elsewhere, e.g. tests/Shared/Processes/ProcessTestFixture.cs. It doesn't need Redis or Docker; it only checks DI registrations.

Before the fix (net11.0):

failed RegistersOutputCachePolicyProvider(api: "builder")
  Assert.NotNull() Failure: Value is null
failed RegistersOutputCachePolicyProvider(api: "plain")
  Assert.NotNull() Failure: Value is null
failed RegistersOutputCachePolicyProvider(api: "keyed")
  Assert.NotNull() Failure: Value is null
  total: 3, failed: 3, succeeded: 0

After the fix (net11.0):

  total: 3, failed: 0, succeeded: 3

How to test

1. Run the new tests on .NET 11:

   dotnet test tests/Aspire.StackExchange.Redis.OutputCaching.Tests -f net11.0 --filter-method "*OutputCachePolicyProvider*"
   

   Expected: 3 passed.

[github-actions]

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/microsoft/aspire/main/eng/scripts/get-aspire-cli-pr.sh | bash -s -- 21222

Or

• Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/microsoft/aspire/main/eng/scripts/get-aspire-cli-pr.ps1) } 21222"

[Curllog (curllog)]

@microsoft-github-policy-service agree

[github-actions]

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[github-actions]

Retrying the failed CI jobs for this pull request from the CI run attempt. The rerun is being tracked in the rerun attempt.