Add test for SortByDependencies

framework/src/Volo.Abp.Core/System/Collections/Generic/AbpListExtensions.cs

@@ -180,7 +180,10 @@ namespace System.Collections.Generic
         /// <typeparam name="T">The type of the members of values.</typeparam>
         /// <param name="source">A list of objects to sort</param>
         /// <param name="getDependencies">Function to resolve the dependencies</param>
-        /// <returns></returns>
+        /// <returns>
+        /// Returns a new list ordered by dependencies.
+        /// If A depends on B, then B will come before than A in the resulting list. 
+        /// </returns>
         public static List<T> SortByDependencies<T>(this IEnumerable<T> source, Func<T, IEnumerable<T>> getDependencies)
         {
             /* See: http://www.codeproject.com/Articles/869059/Topological-sorting-in-Csharp

framework/test/Volo.Abp.Core.Tests/System/Collections/Generic/AbpListExtensions_Tests.cs

@@ -1,5 +1,6 @@
 using System.Linq;
 using Shouldly;
+using Volo.Abp;
 using Xunit;
 
 namespace System.Collections.Generic
@@ -171,5 +172,36 @@ namespace System.Collections.Generic
             list[1].ShouldBe(42);
             list[2].ShouldBe(3);
         }
+
+        [Fact]
+        public void SortByDependencies()
+        {
+            var dependencies = new Dictionary<char, char[]>
+            {
+                {'A', new[] {'B', 'G'}},
+                {'B', new[] {'C', 'E'}},
+                {'C', new[] {'D'}},
+                {'D', new char[0]},
+                {'E', new[] {'C', 'F'}},
+                {'F', new[] {'C'}},
+                {'G', new[] {'F'}}
+            };
+
+            for (int i = 0; i < 3; i++)
+            {
+                var list = RandomHelper
+                    .GenerateRandomizedList(new char[] {'A', 'B', 'C', 'D', 'E', 'F', 'G'});
+                
+                list = list.SortByDependencies(c => dependencies[c]);
+
+                foreach (var dependency in dependencies)
+                {
+                    foreach (var dependedValue in dependency.Value)
+                    {
+                        list.IndexOf(dependency.Key).ShouldBeGreaterThan(list.IndexOf(dependedValue));
+                    }
+                }
+            }
+        }
     }
-}
+}