Add RemoveType methods of PageConventionCollection

src/Microsoft.AspNetCore.Mvc.RazorPages/ApplicationModels/PageConventionCollection.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using Microsoft.AspNetCore.Mvc.RazorPages;
 
@@ -9,6 +10,23 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
 {
     public class PageConventionCollection : Collection<IPageConvention>
     {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="PageConventionCollection"/> class that is empty.
+        /// </summary>
+        public PageConventionCollection()
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="PageConventionCollection"/> class
+        /// as a wrapper for the specified list.
+        /// </summary>
+        /// <param name="conventions">The list that is wrapped by the new collection.</param>
+        public PageConventionCollection(IList<IPageConvention> conventions)
+            : base(conventions)
+        {
+        }
+
         /// <summary>
         /// Creates and adds an <see cref="IPageApplicationModelConvention"/> that invokes an action on the
         /// <see cref="PageApplicationModel"/> for the page with the speciifed name.
@@ -87,6 +105,31 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
             return Add(new FolderRouteModelConvention(folderPath, action));
         }
 
+        /// <summary>
+        /// Removes all <see cref="IPageConvention"/> instances of the specified type.
+        /// </summary>
+        /// <typeparam name="TPageConvention">The type to remove.</typeparam>
+        public void RemoveType<TPageConvention>() where TPageConvention : IPageConvention
+        {
+            RemoveType(typeof(TPageConvention));
+        }
+
+        /// <summary>
+        /// Removes all <see cref="IPageConvention"/> instances of the specified type.
+        /// </summary>
+        /// <param name="pageConventionType">The type to remove.</param>
+        public void RemoveType(Type pageConventionType)
+        {
+            for (var i = Count - 1; i >= 0; i--)
+            {
+                var pageConvention = this[i];
+                if (pageConvention.GetType() == pageConventionType)
+                {
+                    RemoveAt(i);
+                }
+            }
+        }
+
         // Internal for unit testing
         internal static void EnsureValidPageName(string pageName)
         {

test/Microsoft.AspNetCore.Mvc.RazorPages.Test/ApplicationModels/PageConventionCollectionTest.cs

@@ -72,5 +72,49 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
                 "folderPath",
                 "Path must be a root relative path that starts with a forward slash '/'.");
         }
+
+        [Fact]
+        public void RemoveType_RemovesAllOfType()
+        {
+            // Arrange
+            var collection = new PageConventionCollection
+            {
+                new FooPageConvention(),
+                new BarPageConvention(),
+                new FooPageConvention()
+            };
+
+            // Act
+            collection.RemoveType(typeof(FooPageConvention));
+
+            // Assert
+            Assert.Collection(
+                collection,
+                convention => Assert.IsType<BarPageConvention>(convention));
+        }
+
+        [Fact]
+        public void GenericRemoveType_RemovesAllOfType()
+        {
+            // Arrange
+            var collection = new PageConventionCollection
+            {
+                new FooPageConvention(),
+                new BarPageConvention(),
+                new FooPageConvention()
+            };
+
+            // Act
+            collection.RemoveType<FooPageConvention>();
+
+            // Assert
+            Assert.Collection(
+               collection,
+               convention => Assert.IsType<BarPageConvention>(convention));
+        }
+
+        private class FooPageConvention : IPageConvention { }
+
+        private class BarPageConvention : IPageConvention { }
     }
 }