RDG002: Unable to resolve endpoint handler

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	Value
Rule ID	RDG002
Fix is breaking or non-breaking	Non-breaking

Cause

This diagnostic is emitted by the Request Delegate Generator when an endpoint contains a route handler that can't be statically analyzed.

Rule description

The Request Delegate Generator runs at compile-time and needs to be able to statically analyze route handlers in an app. The current implementation only supports route handlers that are provided as a lambda expression, method group references, or references to read-only fields or variables.

The following code generates the RDG002 warning because the route handler is provided as a reference to a method:

:::code language="csharp" source="~/../AspNetCore.Docs.Samples/fundamentals/aot/diagnostics/Rdg2/Program.cs" id="snippet_1" highlight="13-14,25-00":::

How to fix violations

Declare the route handler using supported syntax, such as an inline lambda:

:::code language="csharp" source="~/../AspNetCore.Docs.Samples/fundamentals/aot/diagnostics/Rdg2/Program.cs" id="snippet_1f" highlight="13":::

When to suppress warnings

This warning can be safely suppressed. When suppressed, the framework falls back to generating the request delegate at runtime.