From 7ffab38728014fffdeedbc9906258f693c26167a Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Thu, 8 Oct 2020 17:43:08 +0900
Subject: [PATCH] Add test coverage of TransactionalCommitComponent

---
 .../TransactionalCommitComponentTest.cs       | 100 ++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100644 osu.Game.Tests/Editing/TransactionalCommitComponentTest.cs

diff --git a/osu.Game.Tests/Editing/TransactionalCommitComponentTest.cs b/osu.Game.Tests/Editing/TransactionalCommitComponentTest.cs
new file mode 100644
index 0000000000..4ce9115ec4
--- /dev/null
+++ b/osu.Game.Tests/Editing/TransactionalCommitComponentTest.cs
@@ -0,0 +1,100 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System;
+using NUnit.Framework;
+using osu.Game.Screens.Edit;
+
+namespace osu.Game.Tests.Editing
+{
+    [TestFixture]
+    public class TransactionalCommitComponentTest
+    {
+        private TestHandler handler;
+
+        [SetUp]
+        public void SetUp()
+        {
+            handler = new TestHandler();
+        }
+
+        [Test]
+        public void TestCommitTransaction()
+        {
+            Assert.That(handler.StateUpdateCount, Is.EqualTo(0));
+
+            handler.BeginChange();
+            Assert.That(handler.StateUpdateCount, Is.EqualTo(0));
+            handler.EndChange();
+
+            Assert.That(handler.StateUpdateCount, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void TestSaveOutsideOfTransactionTriggersUpdates()
+        {
+            Assert.That(handler.StateUpdateCount, Is.EqualTo(0));
+
+            handler.SaveState();
+            Assert.That(handler.StateUpdateCount, Is.EqualTo(1));
+
+            handler.SaveState();
+            Assert.That(handler.StateUpdateCount, Is.EqualTo(2));
+        }
+
+        [Test]
+        public void TestEventsFire()
+        {
+            int transactionBegan = 0;
+            int transactionEnded = 0;
+            int stateSaved = 0;
+
+            handler.TransactionBegan += () => transactionBegan++;
+            handler.TransactionEnded += () => transactionEnded++;
+            handler.SaveStateTriggered += () => stateSaved++;
+
+            handler.BeginChange();
+            Assert.That(transactionBegan, Is.EqualTo(1));
+
+            handler.EndChange();
+            Assert.That(transactionEnded, Is.EqualTo(1));
+
+            Assert.That(stateSaved, Is.EqualTo(0));
+            handler.SaveState();
+            Assert.That(stateSaved, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void TestSaveDuringTransactionDoesntTriggerUpdate()
+        {
+            Assert.That(handler.StateUpdateCount, Is.EqualTo(0));
+
+            handler.BeginChange();
+
+            handler.SaveState();
+            Assert.That(handler.StateUpdateCount, Is.EqualTo(0));
+
+            handler.EndChange();
+
+            Assert.That(handler.StateUpdateCount, Is.EqualTo(1));
+        }
+
+        [Test]
+        public void TestEndWithoutBeginThrows()
+        {
+            handler.BeginChange();
+            handler.EndChange();
+            Assert.That(() => handler.EndChange(), Throws.TypeOf<InvalidOperationException>());
+        }
+
+        private class TestHandler : TransactionalCommitComponent
+        {
+            public int StateUpdateCount { get; private set; }
+
+            protected override void UpdateState()
+            {
+                StateUpdateCount++;
+            }
+        }
+    }
+}