2 files changed, 84 insertions, 0 deletions
diff --git a/src/SMAPI.Tests/Core/AssetNameTests.cs b/src/SMAPI.Tests/Core/AssetNameTests.cs
index 655e9bae..fdaa2c01 100644
--- a/src/SMAPI.Tests/Core/AssetNameTests.cs
+++ b/src/SMAPI.Tests/Core/AssetNameTests.cs
@@ -151,6 +151,12 @@ namespace SMAPI.Tests.Core
 
         // with locale codes
         [TestCase("Data/Achievements.fr-FR", "Data/Achievements", ExpectedResult = true)]
+
+        // prefix ends with path separator
+        [TestCase("Data/Events/Boop", "Data/Events/", ExpectedResult = true)]
+        [TestCase("Data/Events/Boop", "Data/Events\\", ExpectedResult = true)]
+        [TestCase("Data/Events", "Data/Events/", ExpectedResult = false)]
+        [TestCase("Data/Events", "Data/Events\\", ExpectedResult = false)]
         public bool StartsWith_SimpleCases(string mainAssetName, string prefix)
         {
             // arrange
@@ -243,6 +249,22 @@ namespace SMAPI.Tests.Core
             return result;
         }
 
+        [TestCase("Mods/SomeMod/SomeSubdirectory", "Mods/Some", true, ExpectedResult = true)]
+        [TestCase("Mods/SomeMod/SomeSubdirectory", "Mods/Some", false, ExpectedResult = false)]
+        [TestCase("Mods/Jasper/Data", "Mods/Jas/Image", true, ExpectedResult = false)]
+        [TestCase("Mods/Jasper/Data", "Mods/Jas/Image", true, ExpectedResult = false)]
+        public bool StartsWith_PartialMatchInPathSegment(string mainAssetName, string otherAssetName, bool allowSubfolder)
+        {
+            // arrange
+            mainAssetName = PathUtilities.NormalizeAssetName(mainAssetName);
+
+            // act
+            AssetName name = AssetName.Parse(mainAssetName, _ => null);
+
+            // assert value
+            return name.StartsWith(otherAssetName, allowPartialWord: true, allowSubfolder: allowSubfolder);
+        }
+
 
         /****
         ** GetHashCode
diff --git a/src/SMAPI.Tests/Core/AssumptionTests.cs b/src/SMAPI.Tests/Core/AssumptionTests.cs
new file mode 100644
index 00000000..efc9da3f
--- /dev/null
+++ b/src/SMAPI.Tests/Core/AssumptionTests.cs
@@ -0,0 +1,62 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using FluentAssertions;
+using FluentAssertions.Execution;
+using NUnit.Framework;
+using StardewModdingAPI.Framework.Models;
+
+namespace SMAPI.Tests.Core
+{
+    /// <summary>Unit tests which validate assumptions about .NET used in the SMAPI implementation.</summary>
+    [TestFixture]
+    internal class AssumptionTests
+    {
+        /*********
+        ** Unit tests
+        *********/
+        /****
+        ** Constructor
+        ****/
+        [Test(Description = $"Assert that {nameof(HashSet<string>)} maintains insertion order when no elements are removed. If this fails, we'll need to change the implementation for the {nameof(SConfig.ModsToLoadEarly)} and {nameof(SConfig.ModsToLoadLate)} options.")]
+        [TestCase("construct from array")]
+        [TestCase("add incrementally")]
+        public void HashSet_MaintainsInsertionOrderWhenNoElementsAreRemoved(string populateMethod)
+        {
+            // arrange
+            string[] inserted = Enumerable.Range(0, 1000)
+                .Select(_ => Guid.NewGuid().ToString("N"))
+                .ToArray();
+
+            // act
+            HashSet<string> set;
+            switch (populateMethod)
+            {
+                case "construct from array":
+                    set = new(inserted, StringComparer.OrdinalIgnoreCase);
+                    break;
+
+                case "add incrementally":
+                    set = new(StringComparer.OrdinalIgnoreCase);
+                    foreach (string value in inserted)
+                        set.Add(value);
+                    break;
+
+                default:
+                    throw new AssertionFailedException($"Unknown populate method '{populateMethod}'.");
+            }
+
+            // assert
+            string[] actualOrder = set.ToArray();
+            actualOrder.Should().HaveCount(inserted.Length);
+            for (int i = 0; i < inserted.Length; i++)
+            {
+                string expected = inserted[i];
+                string actual = actualOrder[i];
+
+                if (actual != expected)
+                    throw new AssertionFailedException($"The hash set differed at index {i}: expected {expected}, but found {actual} instead.");
+            }
+        }
+    }
+}