From 3a857ab58440e2d1fad5d1b8867194027f92c959 Mon Sep 17 00:00:00 2001
From: Andy Butland <abutland73@gmail.com>
Date: Thu, 20 Jul 2023 08:33:49 +0200
Subject: [PATCH] Added tests for TopoGraph. (#14583)

---
 .../Collections/TopoGraphTests.cs             | 126 ++++++++++++++++++
 1 file changed, 126 insertions(+)
 create mode 100644 tests/Umbraco.Tests.UnitTests/Umbraco.Core/Collections/TopoGraphTests.cs

diff --git a/tests/Umbraco.Tests.UnitTests/Umbraco.Core/Collections/TopoGraphTests.cs b/tests/Umbraco.Tests.UnitTests/Umbraco.Core/Collections/TopoGraphTests.cs
new file mode 100644
index 0000000000..ce54c6e762
--- /dev/null
+++ b/tests/Umbraco.Tests.UnitTests/Umbraco.Core/Collections/TopoGraphTests.cs
@@ -0,0 +1,126 @@
+using NUnit.Framework;
+using Umbraco.Cms.Core.Collections;
+
+namespace Umbraco.Cms.Tests.UnitTests.Umbraco.Core.Collections;
+
+[TestFixture]
+public class TopoGraphTests
+{
+    [Test]
+    public void CycleTest()
+    {
+        var graph = new TopoGraph<int, Thing>(x => x.Id, x => x.Dependencies);
+        graph.AddItem(new Thing { Id = 1, Name = "One" }.Depends(3));
+        graph.AddItem(new Thing { Id = 2, Name = "Two" }.Depends(1));
+        graph.AddItem(new Thing { Id = 3, Name = "Three" }.Depends(2));
+
+        try
+        {
+            var ordered = graph.GetSortedItems().ToArray();
+            Assert.Fail("Expected: Exception.");
+        }
+        catch (Exception e)
+        {
+            Assert.IsTrue(e.Message.StartsWith(TopoGraph.CycleDependencyError));
+        }
+    }
+
+    [Test]
+    public void IgnoreCycleTest()
+    {
+        var graph = new TopoGraph<int, Thing>(x => x.Id, x => x.Dependencies);
+        graph.AddItem(new Thing { Id = 1, Name = "One" }.Depends(3));
+        graph.AddItem(new Thing { Id = 2, Name = "Two" }.Depends(1));
+        graph.AddItem(new Thing { Id = 3, Name = "Three" }.Depends(2));
+
+        var ordered = graph.GetSortedItems(throwOnCycle: false).ToArray();
+
+        // default order is dependencies before item
+        Assert.AreEqual(2, ordered[0].Id); // ignored cycle
+        Assert.AreEqual(3, ordered[1].Id);
+        Assert.AreEqual(1, ordered[2].Id);
+    }
+
+    [Test]
+    public void MissingTest()
+    {
+        var graph = new TopoGraph<int, Thing>(x => x.Id, x => x.Dependencies);
+        graph.AddItem(new Thing { Id = 1, Name = "One" }.Depends(4));
+        graph.AddItem(new Thing { Id = 2, Name = "Two" }.Depends(1));
+        graph.AddItem(new Thing { Id = 3, Name = "Three" }.Depends(2));
+
+        try
+        {
+            var ordered = graph.GetSortedItems().ToArray();
+            Assert.Fail("Expected: Exception.");
+        }
+        catch (Exception e)
+        {
+            Assert.IsTrue(e.Message.StartsWith(TopoGraph.MissingDependencyError));
+        }
+    }
+
+    [Test]
+    public void IgnoreMissingTest()
+    {
+        var graph = new TopoGraph<int, Thing>(x => x.Id, x => x.Dependencies);
+        graph.AddItem(new Thing { Id = 1, Name = "One" }.Depends(4));
+        graph.AddItem(new Thing { Id = 2, Name = "Two" }.Depends(1));
+        graph.AddItem(new Thing { Id = 3, Name = "Three" }.Depends(2));
+
+        var ordered = graph.GetSortedItems(throwOnMissing: false).ToArray();
+
+        // default order is dependencies before item
+        Assert.AreEqual(1, ordered[0].Id); // ignored dependency
+        Assert.AreEqual(2, ordered[1].Id);
+        Assert.AreEqual(3, ordered[2].Id);
+    }
+
+    [Test]
+    public void OrderTest()
+    {
+        var graph = new TopoGraph<int, Thing>(x => x.Id, x => x.Dependencies);
+        graph.AddItem(new Thing { Id = 1, Name = "One" });
+        graph.AddItem(new Thing { Id = 2, Name = "Two" }.Depends(1));
+        graph.AddItem(new Thing { Id = 3, Name = "Three" }.Depends(2));
+
+        var ordered = graph.GetSortedItems().ToArray();
+
+        // default order is dependencies before item
+        Assert.AreEqual(1, ordered[0].Id);
+        Assert.AreEqual(2, ordered[1].Id);
+        Assert.AreEqual(3, ordered[2].Id);
+    }
+
+    [Test]
+    public void ReverseTest()
+    {
+        var graph = new TopoGraph<int, Thing>(x => x.Id, x => x.Dependencies);
+        graph.AddItem(new Thing { Id = 1, Name = "One" });
+        graph.AddItem(new Thing { Id = 2, Name = "Two" }.Depends(1));
+        graph.AddItem(new Thing { Id = 3, Name = "Three" }.Depends(2));
+
+        var ordered = graph.GetSortedItems(reverse: true).ToArray();
+
+        // reverse order is item before dependencies
+        Assert.AreEqual(3, ordered[0].Id);
+        Assert.AreEqual(2, ordered[1].Id);
+        Assert.AreEqual(1, ordered[2].Id);
+    }
+
+    public class Thing
+    {
+        public int Id { get; set; }
+
+        public string Name { get; set; }
+
+        public List<int> Dependencies { get; } = new List<int>();
+
+        public Thing Depends(params int[] dependencies)
+        {
+            Dependencies.AddRange(dependencies);
+            return this;
+        }
+    }
+
+}