fix: add Assert.That overloads for ICollection<T> and IReadOnlyCollection<T>

TUnit.Assertions.Tests/Bugs/Issue4446Tests.cs

@@ -0,0 +1,99 @@
+namespace TUnit.Assertions.Tests.Bugs;
+
+/// <summary>
+/// Tests for issue #4446: No Assert.That overload for ICollection/ICollection&lt;T&gt;
+/// https://github.com/thomhurst/TUnit/issues/4446
+/// </summary>
+public class Issue4446Tests
+{
+    [Test]
+    public async Task ICollection_Should_Support_IsEmpty()
+    {
+        ICollection<int> emptyCollection = new List<int>();
+        await Assert.That(emptyCollection).IsEmpty();
+    }
+
+    [Test]
+    public async Task ICollection_Should_Support_IsNotEmpty()
+    {
+        ICollection<int> collection = new List<int> { 1, 2, 3 };
+        await Assert.That(collection).IsNotEmpty();
+    }
+
+    [Test]
+    public async Task ICollection_Should_Support_Contains()
+    {
+        ICollection<int> collection = new List<int> { 1, 2, 3 };
+        await Assert.That(collection).Contains(2);
+    }
+
+    [Test]
+    public async Task ICollection_Should_Support_Count()
+    {
+        ICollection<int> collection = new List<int> { 1, 2, 3 };
+        await Assert.That(collection).HasCount().EqualTo(3);
+    }
+
+    [Test]
+    public async Task ICollection_Should_Support_ContainsOnly()
+    {
+        ICollection<int> collection = new List<int> { 2, 4, 6 };
+        await Assert.That(collection).ContainsOnly(x => x % 2 == 0);
+    }
+
+    [Test]
+    public async Task ICollection_Should_Support_Contains_WithPredicate()
+    {
+        ICollection<int> collection = new List<int> { 1, 2, 3 };
+        await Assert.That(collection).Contains(x => x > 2);
+    }
+
+    [Test]
+    public async Task IReadOnlyCollection_Should_Support_IsEmpty()
+    {
+        IReadOnlyCollection<int> emptyCollection = Array.Empty<int>();
+        await Assert.That(emptyCollection).IsEmpty();
+    }
+
+    [Test]
+    public async Task IReadOnlyCollection_Should_Support_IsNotEmpty()
+    {
+        IReadOnlyCollection<int> collection = new List<int> { 1, 2, 3 };
+        await Assert.That(collection).IsNotEmpty();
+    }
+
+    [Test]
+    public async Task IReadOnlyCollection_Should_Support_Contains()
+    {
+        IReadOnlyCollection<int> collection = new List<int> { 1, 2, 3 };
+        await Assert.That(collection).Contains(2);
+    }
+
+    [Test]
+    public async Task IReadOnlyCollection_Should_Support_Count()
+    {
+        IReadOnlyCollection<int> collection = new List<int> { 1, 2, 3 };
+        await Assert.That(collection).HasCount().EqualTo(3);
+    }
+
+    [Test]
+    public async Task IReadOnlyCollection_Should_Support_IsInOrder()
+    {
+        IReadOnlyCollection<int> collection = new List<int> { 1, 2, 3 };
+        await Assert.That(collection).IsInOrder();
+    }
+
+    [Test]
+    public async Task ICollection_Should_Support_IsInOrder()
+    {
+        ICollection<int> collection = new List<int> { 1, 2, 3 };
+        await Assert.That(collection).IsInOrder();
+    }
+
+    [Test]
+    public async Task ICollection_Should_Support_DoesNotContain()
+    {
+        ICollection<int> collection = new List<int> { 1, 2, 3 };
+        await Assert.That(collection).DoesNotContain(5);
+    }
+}