Endpoint routing failures are cached

[davidfowl]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

When an EndpointDataSources throws an exception while building endpoints the exception is observed once on the first request and subsequent requests end up 404-ing.

Expected Behavior

The exception should be thrown every time.

Steps To Reproduce

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.MapGet("/", () => "Hello World!"u8);

app.Run();

Exceptions (if any)

An exception and then a 404 on the second request.

.NET Version

7.0.100-rc.2.22426.5

Anything else?

No response

[TanayParikh]

Hey @davidfowl where does the exception come from in this case; is it the UTF8 string?

[danroth27]

System.InvalidProgramException: Common Language Runtime detected an invalid program.
at System.Reflection.Emit.DynamicMethod.CreateDelegate(Type delegateType, Object target)
at System.Linq.Expressions.Compiler.LambdaCompiler.Compile(LambdaExpression lambda)
at System.Linq.Expressions.Expression1.Compile() at Microsoft.AspNetCore.Http.RequestDelegateFactory.CreateTargetableRequestDelegate(MethodInfo methodInfo, Expression targetExpression, FactoryContext factoryContext, Expression1 targetFactory)
at Microsoft.AspNetCore.Http.RequestDelegateFactory.Create(Delegate handler, RequestDelegateFactoryOptions options)
at Microsoft.AspNetCore.Routing.RouteEndpointDataSource.CreateRouteEndpointBuilder(RouteEntry entry, RoutePattern groupPrefix, IReadOnlyList1 groupConventions, IReadOnlyList1 groupFinallyConventions)
at Microsoft.AspNetCore.Routing.RouteEndpointDataSource.get_Endpoints()
at Microsoft.AspNetCore.Routing.CompositeEndpointDataSource.CreateEndpointsUnsynchronized()
at Microsoft.AspNetCore.Routing.CompositeEndpointDataSource.EnsureEndpointsInitialized()
at Microsoft.AspNetCore.Routing.DataSourceDependentCache1.Initialize() at System.Threading.LazyInitializer.EnsureInitializedCore[T](T& target, Boolean& initialized, Object& syncLock, Func1 valueFactory)
at Microsoft.AspNetCore.Routing.Matching.DataSourceDependentMatcher..ctor(EndpointDataSource dataSource, Lifetime lifetime, Func1 matcherBuilderFactory) at Microsoft.AspNetCore.Routing.Matching.DfaMatcherFactory.CreateMatcher(EndpointDataSource dataSource) at Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.InitializeCoreAsync() --- End of stack trace from previous location --- at Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.<Invoke>g__AwaitMatcher|8_0(EndpointRoutingMiddleware middleware, HttpContext httpContext, Task1 matcherTask)
at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddlewareImpl.Invoke(HttpContext context)

[davidfowl]

@halter73 can you take a look at this one? It’s from the composite data source changes

[halter73]

Yeah. I'll definitely look into this tomorrow.