Remove aria-invalid when validation state changes to valid

src/Components/Web/src/Forms/InputBase.cs

@@ -226,24 +226,25 @@ public override Task SetParametersAsync(ParameterView parameters)
                     $"{nameof(Forms.EditContext)} dynamically.");
             }
 
-            SetAdditionalAttributesIfValidationFailed();
+            UpdateAdditionalValidationAttributes();
 
             // For derived components, retain the usual lifecycle with OnInit/OnParametersSet/etc.
             return base.SetParametersAsync(ParameterView.Empty);
         }
 
         private void OnValidateStateChanged(object? sender, ValidationStateChangedEventArgs eventArgs)
         {
-            SetAdditionalAttributesIfValidationFailed();
+            UpdateAdditionalValidationAttributes();
 
             StateHasChanged();
         }
 
-        private void SetAdditionalAttributesIfValidationFailed()
+        private void UpdateAdditionalValidationAttributes()
         {
+            var hasAriaInvalidAttribute = AdditionalAttributes != null && AdditionalAttributes.ContainsKey("aria-invalid");
             if (EditContext.GetValidationMessages(FieldIdentifier).Any())
             {
-                if (AdditionalAttributes != null && AdditionalAttributes.ContainsKey("aria-invalid"))
+                if (hasAriaInvalidAttribute)
                 {
                     // Do not overwrite the attribute value
                     return;
@@ -258,6 +259,25 @@ private void SetAdditionalAttributesIfValidationFailed()
                 // we will automatically render the `aria-invalid` attribute when the validation fails
                 additionalAttributes["aria-invalid"] = true;
             }
+            else if (hasAriaInvalidAttribute)
+            {
+                // No validation errors. Need to remove `aria-invalid` if it was rendered already
+
+                if (AdditionalAttributes!.Count == 1)
+                {
+                    // Only aria-invalid argument is present which we don't need any more
+                    AdditionalAttributes = null;
+                }
+                else
+                {
+                    if (ConvertToDictionary(AdditionalAttributes, out var additionalAttributes))
+                    {
+                        AdditionalAttributes = additionalAttributes;
+                    }
+
+                    additionalAttributes.Remove("aria-invalid");
+                }
+            }
         }
 
         /// <summary>

src/Components/Web/test/Forms/InputBaseTest.cs

@@ -468,6 +468,43 @@ public async Task UserSpecifiedAriaValueIsNotChangedIfInvalid()
             Assert.Equal("userSpecifiedValue", component.AdditionalAttributes["aria-invalid"]);
         }
 
+        [Fact]
+        public async Task AriaAttributeRemovedWhenStateChangesToValidFromInvalid()
+        {
+            // Arrange
+            var model = new TestModel();
+            var rootComponent = new TestInputHostComponent<string, TestInputComponent<string>>
+            {
+                EditContext = new EditContext(model),
+                ValueExpression = () => model.StringProperty
+            };
+            var fieldIdentifier = FieldIdentifier.Create(() => model.StringProperty);
+            var renderer = new TestRenderer();
+            var messageStore = new ValidationMessageStore(rootComponent.EditContext);
+            messageStore.Add(fieldIdentifier, "Artificial error message");
+            var rootComponentId = renderer.AssignRootComponentId(rootComponent);
+            await renderer.RenderRootComponentAsync(rootComponentId);
+
+            // Initally, it rendered one batch and is invalid
+            var batch1 = renderer.Batches.Single();
+            var componentFrame1 = batch1.GetComponentFrames<TestInputComponent<string>>().Single();
+            var inputComponentId = componentFrame1.ComponentId;
+            var component = (TestInputComponent<string>)componentFrame1.Component;
+            Assert.Equal("invalid", component.CssClass);
+            Assert.NotNull(component.AdditionalAttributes);
+            Assert.True(component.AdditionalAttributes.ContainsKey("aria-invalid"));
+
+            // Act: update the field state in the EditContext and notify
+            messageStore.Clear(fieldIdentifier);
+            await renderer.Dispatcher.InvokeAsync(rootComponent.EditContext.NotifyValidationStateChanged);
+
+            // Assert: The input component rendered itself again and now has the new class
+            var batch2 = renderer.Batches.Skip(1).Single();
+            Assert.Equal(inputComponentId, batch2.DiffsByComponentId.Keys.Single());
+            Assert.Equal("valid", component.CssClass);
+            Assert.Null(component.AdditionalAttributes);
+        }
+
         class TestModel
         {
             public string StringProperty { get; set; }