From af44a85cfdb505e1806762564b1541cd701263ba Mon Sep 17 00:00:00 2001
From: YoshiRulz <OSSYoshiRulz@gmail.com>
Date: Sun, 4 Dec 2022 06:25:59 +1000
Subject: [PATCH] Add unit tests for `IMemoryApi.{Read,Write}ByteRange`

---
 .../Api/Classes/MemoryApi.cs                  |   2 +-
 .../Client.Common/Api/MemoryApiTests.cs       | 110 ++++++++++++++++++
 2 files changed, 111 insertions(+), 1 deletion(-)
 create mode 100644 src/BizHawk.Tests/Client.Common/Api/MemoryApiTests.cs

diff --git a/src/BizHawk.Client.Common/Api/Classes/MemoryApi.cs b/src/BizHawk.Client.Common/Api/Classes/MemoryApi.cs
index 0cfc267379..b3a3fd202d 100644
--- a/src/BizHawk.Client.Common/Api/Classes/MemoryApi.cs
+++ b/src/BizHawk.Client.Common/Api/Classes/MemoryApi.cs
@@ -13,7 +13,7 @@ namespace BizHawk.Client.Common
 		private IEmulator Emulator { get; set; }
 
 		[OptionalService]
-		private IMemoryDomains MemoryDomainCore { get; set; }
+		public IMemoryDomains MemoryDomainCore { get; set; }
 
 		private readonly Action<string> LogCallback;
 
diff --git a/src/BizHawk.Tests/Client.Common/Api/MemoryApiTests.cs b/src/BizHawk.Tests/Client.Common/Api/MemoryApiTests.cs
new file mode 100644
index 0000000000..b127bd8fc6
--- /dev/null
+++ b/src/BizHawk.Tests/Client.Common/Api/MemoryApiTests.cs
@@ -0,0 +1,110 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+
+using BizHawk.Client.Common;
+using BizHawk.Emulation.Common;
+
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace BizHawk.Tests.Client.Common.Api
+{
+	[TestClass]
+	public sealed class MemoryApiTests
+	{
+		/// <remarks><see cref="CollectionAssert.AreEqual(ICollection, ICollection)"/> and its overloads can't take <see cref="IReadOnlyCollection{T}"/> -_-</remarks>
+		private static void AssertAreSequenceEqual<T>(IReadOnlyList<T> expected, IReadOnlyList<T> actual, string message)
+			=> Assert.IsTrue(actual.SequenceEqual(expected), message);
+
+		private IMemoryApi CreateDummyApi(byte[] memDomainContents)
+			=> new MemoryApi(Console.WriteLine) //TODO capture and check for error messages?
+			{
+				MemoryDomainCore = new MemoryDomainList(new MemoryDomain[]
+				{
+					new MemoryDomainByteArray("ADomain", MemoryDomain.Endian.Little, memDomainContents, writable: true, wordSize: 1),
+				}),
+			};
+
+		[TestMethod]
+		public void TestBulkPeek()
+		{
+			var memApi = CreateDummyApi(new byte[] { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF });
+			AssertAreSequenceEqual(
+				new byte[] { default, default, default },
+				memApi.ReadByteRange(addr: -5, length: 3),
+				"fully below lower boundary");
+			AssertAreSequenceEqual(
+				new byte[] { default, default, 0x01, 0x23 },
+				memApi.ReadByteRange(addr: -2, length: 4),
+				"crosses lower boundary");
+			AssertAreSequenceEqual(
+				new byte[] { default, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, default },
+				memApi.ReadByteRange(addr: -1, length: 10),
+				"crosses both boundaries");
+			AssertAreSequenceEqual(
+				new byte[] { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
+				memApi.ReadByteRange(addr: 0, length: 8),
+				"whole domain");
+			AssertAreSequenceEqual(
+				new byte[] { 0x23, 0x45, 0x67, 0x89, 0xAB },
+				memApi.ReadByteRange(addr: 1, length: 5),
+				"strict contains");
+			AssertAreSequenceEqual(
+				Array.Empty<byte>(),
+				memApi.ReadByteRange(addr: 3, length: 0),
+				"empty");
+			AssertAreSequenceEqual(
+				new byte[] { 0xCD, 0xEF, default },
+				memApi.ReadByteRange(addr: 6, length: 3),
+				"crosses upper boundary");
+			AssertAreSequenceEqual(
+				new byte[] { default, default, default, default },
+				memApi.ReadByteRange(addr: 9, length: 4),
+				"fully above upper boundary");
+		}
+
+		[TestMethod]
+		public void TestBulkPoke()
+		{
+			void TestCase(IReadOnlyList<byte> expected, Action<IMemoryApi> action, string message)
+			{
+				var memDomainContents = new byte[8];
+				action(CreateDummyApi(memDomainContents));
+				AssertAreSequenceEqual(expected, memDomainContents, message);
+			}
+			TestCase(
+				new byte[8],
+				memApi => memApi.WriteByteRange(-5, new byte[] { 0x01, 0x23, 0x45 }),
+				"fully below lower boundary");
+			TestCase(
+				new byte[] { 0x45, 0x67, default, default, default, default, default, default },
+				memApi => memApi.WriteByteRange(-2, new byte[] { 0x01, 0x23, 0x45, 0x67 }),
+				"crosses lower boundary");
+			TestCase(
+				new byte[] { 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0xFE },
+				memApi => memApi.WriteByteRange(-1, new byte[] { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0xFE, 0xDC }),
+				"crosses both boundaries");
+			TestCase(
+				new byte[] { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
+				memApi => memApi.WriteByteRange(0, new byte[] { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF }),
+				"whole domain");
+			TestCase(
+				new byte[] { default, 0x01, 0x23, 0x45, 0x67, 0x89, default, default },
+				memApi => memApi.WriteByteRange(1, new byte[] { 0x01, 0x23, 0x45, 0x67, 0x89 }),
+				"strict contains");
+			TestCase(
+				new byte[8],
+				memApi => memApi.WriteByteRange(3, Array.Empty<byte>()),
+				"empty");
+			TestCase(
+				new byte[] { default, default, default, default, default, default, 0x01, 0x23 },
+				memApi => memApi.WriteByteRange(6, new byte[] { 0x01, 0x23, 0x45 }),
+				"crosses upper boundary");
+			TestCase(
+				new byte[8],
+				memApi => memApi.WriteByteRange(9, new byte[] { 0x01, 0x23, 0x45, 0x67 }),
+				"fully above upper boundary");
+		}
+	}
+}