Use the annotation resolver in ValueProvider

Author: mhutch

src/System.CommandLine.Subsystems/ValueAnnotationExtensions.cs

@@ -17,9 +17,12 @@ public static class ValueAnnotationExtensions
     /// <param name="option">The option</param>
     /// <returns>The option's default value annotation if any, otherwise <see langword="null"/></returns>
     /// <remarks>
-    /// This is intended to be called by CLI authors. Subsystems should instead call <see cref="PipelineResult.GetValue{T}(CliOption)"/>,
-    /// which calculates the actual default value, based on the default value annotation and default value calculation,
-    /// whether directly stored on the symbol or from the subsystem's <see cref="IAnnotationProvider"/>.
+    /// This is intended to be called by CLI authors inspecting the default value source they have
+    /// associated directly with the <paramref name="valueSymbol"/>.
+    /// <para>
+    /// Subsystems should instead use <see cref="PipelineResult.GetValue(CliValueSymbol)"/>, which caches calculated
+    /// values and respects dynamic/lazy annotations from the <see cref="Pipeline.AnnotationProviders"/>.
+    /// </para>
     /// </remarks>
     public static bool TryGetDefaultValueSource(this CliValueSymbol valueSymbol, [NotNullWhen(true)] out ValueSource? defaultValueSource)
         => valueSymbol.TryGetAnnotation(ValueAnnotations.DefaultValueSource, out defaultValueSource);

src/System.CommandLine.Subsystems/ValueProvider.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System.CommandLine.Subsystems.Annotations;
 using System.CommandLine.ValueSources;
 
 namespace System.CommandLine;
@@ -48,7 +49,7 @@ private bool TryGetValue<T>(CliSymbol symbol, out T? value)
         {
             return UseValue(valueSymbol, valueResult.GetValue<T>());
         }
-        if (valueSymbol.TryGetDefaultValueSource(out ValueSource? defaultValueSource))
+        if (pipelineResult.Annotations.TryGet(valueSymbol, ValueAnnotations.DefaultValueSource, out ValueSource? defaultValueSource))
         {
             if (defaultValueSource is not ValueSource<T> typedDefaultValueSource)
             {