Make ValidationContext a required property

Author: captainsafia

src/Http/Http.Abstractions/src/PublicAPI.Unshipped.txt

@@ -24,7 +24,7 @@ Microsoft.AspNetCore.Http.Validation.ValidateContext.CurrentDepth.set -> void
 Microsoft.AspNetCore.Http.Validation.ValidateContext.CurrentValidationPath.get -> string!
 Microsoft.AspNetCore.Http.Validation.ValidateContext.CurrentValidationPath.set -> void
 Microsoft.AspNetCore.Http.Validation.ValidateContext.ValidateContext() -> void
-Microsoft.AspNetCore.Http.Validation.ValidateContext.ValidationContext.get -> System.ComponentModel.DataAnnotations.ValidationContext?
+Microsoft.AspNetCore.Http.Validation.ValidateContext.ValidationContext.get -> System.ComponentModel.DataAnnotations.ValidationContext!
 Microsoft.AspNetCore.Http.Validation.ValidateContext.ValidationContext.set -> void
 Microsoft.AspNetCore.Http.Validation.ValidateContext.ValidationErrors.get -> System.Collections.Generic.Dictionary<string!, string![]!>?
 Microsoft.AspNetCore.Http.Validation.ValidateContext.ValidationErrors.set -> void

src/Http/Http.Abstractions/src/Validation/ValidatableParameterInfo.cs

@@ -63,11 +63,6 @@ public virtual async Task ValidateAsync(object? value, ValidateContext context,
             return;
         }
 
-        // ValidationContext requires a non-null value although the invocation pattern that we use
-        // calls `GetValidationResult` and passes the value there. `GetValidationResult` tolerates
-        // null values so we only need to set a non-null value to the ValidationContext here.
-        context.ValidationContext ??= new ValidationContext(value ?? new object(), displayName: DisplayName, serviceProvider: null, items: null);
-
         context.ValidationContext.DisplayName = DisplayName;
         context.ValidationContext.MemberName = Name;
 

src/Http/Http.Abstractions/src/Validation/ValidatablePropertyInfo.cs

@@ -74,8 +74,6 @@ public virtual async Task ValidateAsync(object? value, ValidateContext context,
             context.CurrentValidationPath = $"{originalPrefix}.{Name}";
         }
 
-        context.ValidationContext ??= new ValidationContext(value ?? new object(), displayName: DisplayName, serviceProvider: null, items: null);
-
         context.ValidationContext.DisplayName = DisplayName;
         context.ValidationContext.MemberName = Name;
 

src/Http/Http.Abstractions/src/Validation/ValidatableTypeInfo.cs

@@ -48,10 +48,6 @@ public virtual async Task ValidateAsync(object? value, ValidateContext context,
             return;
         }
 
-        // Although classes can be annotated with [DisplayName], we only process display names when producing
-        // errors for properties so we can pass the `Type.Name` as the display name for the type here.
-        context.ValidationContext ??= new ValidationContext(value, displayName: Type.Name, serviceProvider: null, items: null);
-
         // Check if we've exceeded the maximum depth
         if (context.CurrentDepth >= context.ValidationOptions.MaxDepth)
         {

src/Http/Http.Abstractions/src/Validation/ValidateContext.cs

@@ -14,7 +14,24 @@ public sealed class ValidateContext
     /// Gets or sets the validation context used for validating objects that implement <see cref="IValidatableObject"/> or have <see cref="ValidationAttribute"/>.
     /// This context provides access to service provider and other validation metadata.
     /// </summary>
-    public ValidationContext? ValidationContext { get; set; }
+    /// <remarks>
+    /// This property should be set by the consumer of the <see cref="IValidatableInfo"/>
+    /// interface to provide the necessary context for validation. The object should be initialized
+    /// with the current object being validated, the display name, and the service provider to support
+    /// the complete set of validation scenarios.
+    /// </remarks>
+    /// <example>
+    /// <code>
+    /// var validationContext = new ValidationContext(objectToValidate, serviceProvider, items);
+    /// var validationOptions = serviceProvider.GetService&lt;IOptions&lt;ValidationOptions&gt;&gt;()?.Value;
+    /// var validateContext = new ValidateContext
+    /// {
+    ///     ValidationContext = validationContext,
+    ///     ValidationOptions = validationOptions
+    /// };
+    /// </code>
+    /// </example>
+    public required ValidationContext ValidationContext { get; set; }
 
     /// <summary>
     /// Gets or sets the prefix used to identify the current object being validated in a complex object graph.

src/Http/Http.Abstractions/test/Validation/ValidatableParameterInfoTests.cs

@@ -285,60 +285,6 @@ public async Task Validate_ExceptionDuringValidation_CapturesExceptionAsError()
         Assert.Equal("Test exception", error.Value.First());
     }
 
-    [Fact]
-    public async Task Validate_WithoutValidationContext_RequiredParameter_AddsErrorAndInitializesValidationContext()
-    {
-        // Arrange
-        var paramInfo = CreateTestParameterInfo(
-            parameterType: typeof(string),
-            name: "testParam",
-            displayName: "Test Parameter",
-            validationAttributes: [new RequiredAttribute()]);
-
-        // Create a ValidateContext without a pre-populated ValidationContext
-        var context = new ValidateContext
-        {
-            ValidationOptions = new TestValidationOptions(new Dictionary<Type, ValidatableTypeInfo>())
-        };
-
-        // Sanity check
-        Assert.Null(context.ValidationContext);
-
-        // Act
-        await paramInfo.ValidateAsync(null, context, default);
-
-        // Assert – a ValidationContext should have been created and the error recorded
-        Assert.NotNull(context.ValidationContext);
-        var errors = context.ValidationErrors;
-        Assert.NotNull(errors);
-        var error = Assert.Single(errors);
-        Assert.Equal("testParam", error.Key);
-        Assert.Equal("The Test Parameter field is required.", error.Value.Single());
-    }
-
-    [Fact]
-    public async Task Validate_WithoutValidationContext_ValidValue_NoErrors()
-    {
-        // Arrange
-        var paramInfo = CreateTestParameterInfo(
-            parameterType: typeof(int),
-            name: "testParam",
-            displayName: "Test Parameter",
-            validationAttributes: [new RangeAttribute(10, 100)]);
-
-        var context = new ValidateContext
-        {
-            ValidationOptions = new TestValidationOptions(new Dictionary<Type, ValidatableTypeInfo>())
-        };
-
-        // Act
-        await paramInfo.ValidateAsync(50, context, default);
-
-        // Assert – ValidationContext initialized, but no errors added
-        Assert.NotNull(context.ValidationContext);
-        Assert.Null(context.ValidationErrors);
-    }
-
     private TestValidatableParameterInfo CreateTestParameterInfo(
         Type parameterType,
         string name,