diff --git a/.gitea/workflows/test-dotnet.yaml b/.gitea/workflows/test-dotnet.yaml
index 3dfb5d8..63e9466 100644
--- a/.gitea/workflows/test-dotnet.yaml
+++ b/.gitea/workflows/test-dotnet.yaml
@@ -15,13 +15,19 @@ jobs:
   test:
     runs-on: ubuntu-latest
 
-    steps:
-    - uses: actions/checkout@v3
+    strategy:
+      matrix:
+        dotnet-version: [ '8.x', '9.x' ]
+    env:
+      DOTNET_CLI_TELEMETRY_OPTOUT: 'true'
 
-    - name: Setup .NET
-      uses: https://github.com/actions/setup-dotnet@v3
+    steps:
+    - uses: actions/checkout@v5
+
+    - name: Setup .NET ${{ matrix.dotnet-version }}
+      uses: https://github.com/actions/setup-dotnet@v4
       with:
-        dotnet-version: 9.x
+        dotnet-version: ${{ matrix.dotnet-version }}
 
     - name: Restore dependencies
       run: dotnet restore
@@ -30,12 +36,12 @@ jobs:
       run: dotnet build --no-restore
 
     - name: Test
-      run: dotnet test --no-build --verbosity normal --logger trx --results-directory "TestResults-9.x"
+      run: dotnet test --no-build --verbosity normal --logger trx --results-directory "TestResults-${{ matrix.dotnet-version }}"
 
     - name: Upload dotnet test results
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
-        name: dotnet-results-9.x
-        path: TestResults-9.x
+        name: dotnet-results-${{ matrix.dotnet-version }}
+        path: TestResults-${{ matrix.dotnet-version }}
         if: ${{ always() }}
         retention-days: 30
diff --git a/.vscode/settings.json b/.vscode/settings.json
index 09cb4c4..b3259f8 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,4 +1,5 @@
 {
     "dotnet.defaultSolution": "JustDotNet.Core.sln",
-    "dotnetAcquisitionExtension.enableTelemetry": false
+    "dotnetAcquisitionExtension.enableTelemetry": false,
+    "dotnet.testWindow.useTestingPlatformProtocol": true
 }
diff --git a/Core.Tests/Base32Conversions/Decode.cs b/Core.Tests/Base32Conversions/Decode.cs
index 21ce83a..f474c04 100644
--- a/Core.Tests/Base32Conversions/Decode.cs
+++ b/Core.Tests/Base32Conversions/Decode.cs
@@ -19,7 +19,7 @@ public class Decode
             var resultString = Base32.Encode(testBytes);
             var resultBytes = Base32.Decode(resultString);
 
-            resultBytes.Should().BeEquivalentTo(testBytes);
+            resultBytes.ShouldBeEquivalentTo(testBytes);
         }
     }
 
@@ -34,7 +34,7 @@ public class Decode
     public void WhenCalledWithValidString_ShouldReturnValidByteArray(string str, byte[] expected)
     {
         var actualBytesArray = Base32.Decode(str);
-        actualBytesArray.Should().Equal(expected);
+        actualBytesArray.ShouldBe(expected);
     }
 
     [Theory]
@@ -44,7 +44,7 @@ public class Decode
     public void WhenCalledWithValidStringThatEndsWithPaddingSign_ShouldReturnValidByteArray(string testString, byte[] expected)
     {
         var actualBytesArray = Base32.Decode(testString);
-        actualBytesArray.Should().Equal(expected);
+        actualBytesArray.ShouldBe(expected);
     }
 
     [Theory]
@@ -54,7 +54,7 @@ public class Decode
     public void WhenCalledWithValidStringWithoutPaddingSign_ShouldReturnValidByteArray(string testString, byte[] expected)
     {
         var actualBytesArray = Base32.Decode(testString);
-        actualBytesArray.Should().Equal(expected);
+        actualBytesArray.ShouldBe(expected);
     }
 
     [Theory]
@@ -66,7 +66,7 @@ public class Decode
     public void WhenCalledWithNotValidString_ShouldThrowFormatException(string testString)
     {
         Action action = () => Base32.Decode(testString);
-        action.Should().Throw<FormatException>();
+        action.ShouldThrow<FormatException>();
     }
 
     [Theory]
@@ -74,6 +74,6 @@ public class Decode
     [InlineData("")]
     public void WhenCalledWithNullString_ShouldReturnEmptyArray(string? testString)
     {
-        Base32.Decode(testString).Should().BeEmpty();
+        Base32.Decode(testString).ShouldBeEmpty();
     }
 }
diff --git a/Core.Tests/Base32Conversions/Encode.cs b/Core.Tests/Base32Conversions/Encode.cs
index e3e1751..230afc0 100644
--- a/Core.Tests/Base32Conversions/Encode.cs
+++ b/Core.Tests/Base32Conversions/Encode.cs
@@ -31,7 +31,7 @@ public class Encode
         var resultBytes = Base32.Decode(testString);
         var resultString = Base32.Encode(resultBytes);
 
-        resultString.Should().Be(testString);
+        resultString.ShouldBe(testString);
     }
 
     [Theory]
@@ -47,7 +47,7 @@ public class Encode
     public void WhenCalledWithNotEmptyByteArray_ShouldReturnValidString(string expected, byte[] testArray)
     {
         var str = Base32.Encode(testArray);
-        str.Should().Be(expected);
+        str.ShouldBe(expected);
     }
 
     [Theory]
@@ -56,7 +56,7 @@ public class Encode
     public void WhenCalledWithEmptyByteArray_ShouldReturnEmptyString(byte[]? testArray)
     {
         var actualBase32 = Base32.Encode(testArray);
-        actualBase32.Should().Be(string.Empty);
+        actualBase32.ShouldBe(string.Empty);
     }
 
     [Theory]
@@ -68,7 +68,7 @@ public class Encode
 
         var charsWritten = Base32.Encode(testArray, output);
 
-        charsWritten.Should().Be(0);
-        output.Should().Equal(['1', '2', '3', '4']);
+        charsWritten.ShouldBe(0);
+        output.ShouldBe(['1', '2', '3', '4']);
     }
 }
diff --git a/Core.Tests/Base64UrlConversions/Decode.cs b/Core.Tests/Base64UrlConversions/Decode.cs
index 6baf0ea..4a26894 100644
--- a/Core.Tests/Base64UrlConversions/Decode.cs
+++ b/Core.Tests/Base64UrlConversions/Decode.cs
@@ -19,7 +19,7 @@ public class Decode
             var resultString = Base64Url.Encode(testBytes);
             var resultBytes = Base64Url.Decode(resultString);
 
-            resultBytes.Should().BeEquivalentTo(testBytes);
+            resultBytes.ShouldBeEquivalentTo(testBytes);
         }
     }
 
@@ -39,7 +39,7 @@ public class Decode
             var resultString = Base64Url.Encode(testLong);
             var resultLong = Base64Url.DecodeLong(resultString);
 
-            resultLong.Should().Be(testLong);
+            resultLong.ShouldBe(testLong);
         }
     }
 
@@ -57,7 +57,7 @@ public class Decode
     public void WhenCalled_ShouldReturnValidLong(string testString, long expected)
     {
         var result = Base64Url.DecodeLong(testString);
-        result.Should().Be(expected);
+        result.ShouldBe(expected);
     }
 
     [Theory]
@@ -70,7 +70,7 @@ public class Decode
     {
         var result = Base64Url.DecodeGuid(testString);
         var expected = Guid.Parse(expectedStr);
-        result.Should().Be(expected);
+        result.ShouldBe(expected);
     }
 
     [Theory]
@@ -85,7 +85,7 @@ public class Decode
     public void WhenCalled_ShouldReturnValidBytes(string testString, byte[] expected)
     {
         var result = Base64Url.Decode(testString);
-        result.Should().BeEquivalentTo(expected);
+        result.ShouldBeEquivalentTo(expected);
     }
 
     [Theory]
@@ -97,7 +97,7 @@ public class Decode
     public void WhenCalledWithInvalidString_ShouldThrowFormatException(string testString)
     {
         Action action = () => Base64Url.Decode(testString);
-        action.Should().Throw<FormatException>();
+        action.ShouldThrow<FormatException>();
     }
 
     [Theory]
@@ -109,7 +109,7 @@ public class Decode
     public void WhenCalledWithInvalidGuidString_ShouldThrowFormatException(string testString)
     {
         Action action = () => Base64Url.DecodeGuid(testString);
-        action.Should().Throw<FormatException>();
+        action.ShouldThrow<FormatException>();
     }
 
     [Theory]
@@ -122,7 +122,7 @@ public class Decode
     public void WhenCalledWithInvalidLongString_ShouldThrowFormatException(string testString)
     {
         Action action = () => Base64Url.DecodeLong(testString);
-        action.Should().Throw<FormatException>();
+        action.ShouldThrow<FormatException>();
     }
 
     [Theory]
@@ -130,6 +130,6 @@ public class Decode
     [InlineData("")]
     public void WhenCalledWithNullString_ShouldReturnEmptyArray(string? testString)
     {
-        Base64Url.Decode(testString).Should().BeEmpty();
+        Base64Url.Decode(testString).ShouldBeEmpty();
     }
 }
diff --git a/Core.Tests/Base64UrlConversions/Encode.cs b/Core.Tests/Base64UrlConversions/Encode.cs
index 9b9fa25..a598b5c 100644
--- a/Core.Tests/Base64UrlConversions/Encode.cs
+++ b/Core.Tests/Base64UrlConversions/Encode.cs
@@ -12,7 +12,7 @@ public class Encode
     {
         var testGuid = Guid.Parse(testGuidString);
         var result = Base64Url.Encode(testGuid);
-        result.Should().Be(expected);
+        result.ShouldBe(expected);
     }
 
     [Theory]
@@ -29,7 +29,7 @@ public class Encode
     public void WhenCalledWithLong_ShouldReturnValidString(string expected, long testLong)
     {
         var result = Base64Url.Encode(testLong);
-        result.Should().Be(expected);
+        result.ShouldBe(expected);
     }
 
     [Theory]
@@ -44,7 +44,7 @@ public class Encode
     public void WhenCalled_ShouldReturnValidString(string expected, byte[] testBytes)
     {
         var result = Base64Url.Encode(testBytes);
-        result.Should().Be(expected);
+        result.ShouldBe(expected);
     }
 
     [Theory]
@@ -53,7 +53,7 @@ public class Encode
     public void WhenCalledWithEmptyByteArray_ShouldReturnEmptyString(byte[]? testArray)
     {
         var actualBase32 = Base64Url.Encode(testArray);
-        actualBase32.Should().Be(string.Empty);
+        actualBase32.ShouldBe(string.Empty);
     }
 
     [Theory]
@@ -65,7 +65,7 @@ public class Encode
 
         var charsWritten = Base64Url.Encode(testArray, output);
 
-        charsWritten.Should().Be(0);
-        output.Should().Equal(['1', '2', '3', '4']);
+        charsWritten.ShouldBe(0);
+        output.ShouldBe((char[])['1', '2', '3', '4']);
     }
 }
diff --git a/Core.Tests/Core.Tests.csproj b/Core.Tests/Core.Tests.csproj
index dc2a347..bb1aab0 100644
--- a/Core.Tests/Core.Tests.csproj
+++ b/Core.Tests/Core.Tests.csproj
@@ -1,10 +1,11 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net9.0</TargetFramework>
+    <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
-    
+    <OutputType>Exe</OutputType>
+
     <AssemblyName>Just.Core.Tests</AssemblyName>
     <RootNamespace>Just.Core.Tests</RootNamespace>
 
@@ -14,13 +15,8 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="FluentAssertions" Version="6.12.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
-    <PackageReference Include="xunit" Version="2.9.3" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="3.1.3">
-      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
-      <PrivateAssets>all</PrivateAssets>
-    </PackageReference>
+    <PackageReference Include="Shouldly" Version="4.3.0" />
+    <PackageReference Include="xunit.v3" Version="3.2.0" />
     <PackageReference Include="coverlet.collector" Version="6.0.4">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
diff --git a/Core.Tests/GlobalUsings.cs b/Core.Tests/GlobalUsings.cs
index 91743bb..b37457e 100644
--- a/Core.Tests/GlobalUsings.cs
+++ b/Core.Tests/GlobalUsings.cs
@@ -1,2 +1,2 @@
 global using Xunit;
-global using FluentAssertions;
+global using Shouldly;
diff --git a/Core.Tests/GuidV8Tests/NewGuid.cs b/Core.Tests/GuidV8Tests/NewGuid.cs
index 2fbfa58..f18055c 100644
--- a/Core.Tests/GuidV8Tests/NewGuid.cs
+++ b/Core.Tests/GuidV8Tests/NewGuid.cs
@@ -14,8 +14,19 @@ public class NewGuid
         {
             var timestamp = referenceTime.AddSeconds(rng.Next());
             var result = GuidV8.NewGuid(timestamp, entropy);
-            result.Version.Should().Be(8);
-            (result.Variant & 0b1100).Should().Be(0b1000);
+
+#if NET9_0_OR_GREATER
+            result.Version.ShouldBe(8);
+            (result.Variant & 0b1100).ShouldBe(0b1000);
+#else
+            var bytes = result.ToByteArray();
+            // Check version (bits 4-7 of the 7th byte)
+            var version = (bytes[7] >> 4) & 0x0F;
+            version.ShouldBe(8); // UUID version 8
+            // Check variant (bits 6-7 of the 8th byte)
+            var variant = bytes[8] >> 6;
+            variant.ShouldBe(0b10); // Standard UUID variant
+#endif
         }
     }
 
@@ -86,11 +97,11 @@ public class NewGuid
         var sut = expected.Values.ToArray();
         rng.Shuffle(sut);
 
-        sut.Order().Should().Equal(expected.Select(x => x.Value));
-        sut.OrderBy(x => x.ToString()).Should().Equal(expected.Select(x => x.Value));
+        sut.Order().ShouldBe(expected.Select(x => x.Value));
+        sut.OrderBy(x => x.ToString()).ShouldBe(expected.Select(x => x.Value));
 
-        sut.OrderDescending().Should().Equal(expected.Reverse().Select(x => x.Value));
-        sut.OrderByDescending(x => x.ToString()).Should().Equal(expected.Reverse().Select(x => x.Value));
+        sut.OrderDescending().ShouldBe(expected.Reverse().Select(x => x.Value));
+        sut.OrderByDescending(x => x.ToString()).ShouldBe(expected.Reverse().Select(x => x.Value));
     }
 
     [Theory]
@@ -160,11 +171,11 @@ public class NewGuid
         var sut = expected.Values.ToArray();
         rng.Shuffle(sut);
 
-        sut.Order().Should().Equal(expected.Select(x => x.Value));
-        sut.OrderBy(x => x.ToString()).Should().Equal(expected.Select(x => x.Value));
+        sut.Order().ShouldBe(expected.Select(x => x.Value));
+        sut.OrderBy(x => x.ToString()).ShouldBe(expected.Select(x => x.Value));
 
-        sut.OrderDescending().Should().Equal(expected.Reverse().Select(x => x.Value));
-        sut.OrderByDescending(x => x.ToString()).Should().Equal(expected.Reverse().Select(x => x.Value));
+        sut.OrderDescending().ShouldBe(expected.Reverse().Select(x => x.Value));
+        sut.OrderByDescending(x => x.ToString()).ShouldBe(expected.Reverse().Select(x => x.Value));
     }
 
     [Theory]
@@ -234,10 +245,10 @@ public class NewGuid
         var sut = expected.Values.ToArray();
         rng.Shuffle(sut);
 
-        sut.Order().Should().Equal(expected.Select(x => x.Value));
-        sut.OrderBy(x => x.ToString()).Should().Equal(expected.Select(x => x.Value));
+        sut.Order().ShouldBe(expected.Select(x => x.Value));
+        sut.OrderBy(x => x.ToString()).ShouldBe(expected.Select(x => x.Value));
 
-        sut.OrderDescending().Should().Equal(expected.Reverse().Select(x => x.Value));
-        sut.OrderByDescending(x => x.ToString()).Should().Equal(expected.Reverse().Select(x => x.Value));
+        sut.OrderDescending().ShouldBe(expected.Reverse().Select(x => x.Value));
+        sut.OrderByDescending(x => x.ToString()).ShouldBe(expected.Reverse().Select(x => x.Value));
     }
 }
diff --git a/Core.Tests/SeqIdTests/NextId.cs b/Core.Tests/SeqIdTests/NextId.cs
index 9892abe..8d55af0 100644
--- a/Core.Tests/SeqIdTests/NextId.cs
+++ b/Core.Tests/SeqIdTests/NextId.cs
@@ -1,3 +1,4 @@
+
 namespace Just.Core.Tests.SeqIdTests;
 
 public class NextId
@@ -25,9 +26,9 @@ public class NextId
         long sequencePart = (id >> SeqShift) & SeqMask;
         long randomPart = id & RandMask;
 
-        timestampPart.Should().Be(500);
-        sequencePart.Should().Be(0);
-        randomPart.Should().BeInRange(0, RandMask);
+        timestampPart.ShouldBe(500);
+        sequencePart.ShouldBe(0);
+        randomPart.ShouldBeInRange(0, RandMask);
     }
 
     [Fact]
@@ -44,7 +45,7 @@ public class NextId
         long sequence1 = (id1 >> SeqShift) & SeqMask;
         long sequence2 = (id2 >> SeqShift) & SeqMask;
 
-        sequence2.Should().Be(sequence1 + 1);
+        sequence2.ShouldBe(sequence1 + 1);
     }
 
     [Fact]
@@ -61,7 +62,7 @@ public class NextId
 
         // Assert
         long sequence = (id >> SeqShift) & SeqMask;
-        sequence.Should().Be(0);
+        sequence.ShouldBe(0);
     }
 
     [Fact]
@@ -74,7 +75,7 @@ public class NextId
         // Act & Assert
         _seqId.Next(time1); // First call sets last timestamp
         Action act = () => _seqId.Next(time2);
-        act.Should().Throw<InvalidOperationException>()
+        act.ShouldThrow<InvalidOperationException>()
             .WithMessage("Refused to create new SeqId. Last timestamp is in the future.");
     }
 
@@ -90,7 +91,7 @@ public class NextId
             _seqId.Next(time); // Exhauste sequence
         }
         Action act = () => _seqId.Next(time);
-        act.Should().Throw<IndexOutOfRangeException>()
+        act.ShouldThrow<IndexOutOfRangeException>()
             .WithMessage("Refused to create new SeqId. Sequence exhausted.");
     }
 
@@ -105,7 +106,7 @@ public class NextId
 
         // Assert
         long randomPart = id & RandMask;
-        randomPart.Should().BeInRange(0, RandMask);
+        randomPart.ShouldBeInRange(0, RandMask);
     }
 
     [Fact]
@@ -119,7 +120,7 @@ public class NextId
 
         // Assert
         long randomPart = id & RandMask;
-        randomPart.Should().BeInRange(0, RandMask);
+        randomPart.ShouldBeInRange(0, RandMask);
     }
 
     [Fact]
@@ -127,14 +128,14 @@ public class NextId
     {
         // Arrange
         var now = DateTime.UtcNow;
-        var defaultEpoch = new DateTime(2025, 1, 1, 0, 0, 0, DateTimeKind.Utc);
-        long expectedTimestamp = (long)(now - defaultEpoch).TotalMilliseconds;
+        var defaultEpoch = SeqId.DefaultEpoch;
+        long expectedTimestamp = ((long)(now - defaultEpoch).TotalMilliseconds) & TimestampMask; // Mask handles overflow
 
         // Act
         long id = SeqId.NextId();
 
         // Assert
         long timestampPart = (id >> TimestampShift) & TimestampMask;
-        timestampPart.Should().BeCloseTo(expectedTimestamp & TimestampMask, 1); // Mask handles overflow
+        timestampPart.ShouldBeInRange(expectedTimestamp, expectedTimestamp + 1);
     }
 }
\ No newline at end of file
diff --git a/Core.Tests/ShouldlyExtensions.cs b/Core.Tests/ShouldlyExtensions.cs
new file mode 100644
index 0000000..9b217c5
--- /dev/null
+++ b/Core.Tests/ShouldlyExtensions.cs
@@ -0,0 +1,11 @@
+namespace Just.Core.Tests;
+
+public static class ShouldlyExtensions
+{
+    public static TException WithMessage<TException>(this TException exception, string expectedMessage, string? customMessage = null)
+        where TException : Exception
+    {
+        exception.Message.ShouldBe(expectedMessage, customMessage: customMessage);
+        return exception;
+    }
+}
diff --git a/Core.Tests/SystemIOStreamExtensionsTests/Populate.cs b/Core.Tests/SystemIOStreamExtensionsTests/Populate.cs
index 875a643..17e38b7 100644
--- a/Core.Tests/SystemIOStreamExtensionsTests/Populate.cs
+++ b/Core.Tests/SystemIOStreamExtensionsTests/Populate.cs
@@ -23,7 +23,7 @@ public class Populate
 
         stream.Populate(buffer, offset, length);
 
-        buffer.Skip(offset).Take(length).Should().Equal(streamContent.Take(length));
+        buffer.Skip(offset).Take(length).ShouldBe(streamContent.Take(length));
     }
 
     [Theory]
@@ -38,7 +38,7 @@ public class Populate
 
         stream.Populate(buffer);
 
-        buffer.Should().Equal(streamContent.Take(bufferSize));
+        buffer.ShouldBe(streamContent.Take(bufferSize));
     }
 
     [Theory]
@@ -53,6 +53,6 @@ public class Populate
 
         Action action = () => stream.Populate(buffer);
 
-        action.Should().Throw<EndOfStreamException>();
+        action.ShouldThrow<EndOfStreamException>();
     }
 }
diff --git a/Core.Tests/SystemIOStreamExtensionsTests/PopulateAsync.cs b/Core.Tests/SystemIOStreamExtensionsTests/PopulateAsync.cs
index 70aa318..3bf68c4 100644
--- a/Core.Tests/SystemIOStreamExtensionsTests/PopulateAsync.cs
+++ b/Core.Tests/SystemIOStreamExtensionsTests/PopulateAsync.cs
@@ -15,7 +15,7 @@ public class PopulateAsync
         Func<Task> action = async () => await stream.PopulateAsync(buffer, cts.Token);
         cts.Cancel();
 
-        await action.Should().ThrowAsync<OperationCanceledException>();
+        await action.ShouldThrowAsync<OperationCanceledException>();
     }
 
     [Theory]
@@ -31,13 +31,14 @@ public class PopulateAsync
     [InlineData(5, 5)]
     public async Task WhenCalled_ShouldPopulateSpecifiedRange(int offset, int length)
     {
+        using var cts = new CancellationTokenSource(TimeSpan.FromMilliseconds(50));
         byte[] streamContent = [0x01, 0x02, 0x03, 0x04, 0x05,];
         using var stream = new MemoryStream(streamContent);
         var buffer = new byte[10];
 
-        await stream.PopulateAsync(buffer, offset, length);
+        await stream.PopulateAsync(buffer, offset, length, cts.Token);
 
-        buffer.Skip(offset).Take(length).Should().Equal(streamContent.Take(length));
+        buffer.Skip(offset).Take(length).ShouldBe(streamContent.Take(length));
     }
 
     [Theory]
@@ -47,12 +48,13 @@ public class PopulateAsync
     [InlineData(new byte[]{ 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, }, 5)]
     public async Task WhenStreamContainsSameOrGreaterAmmountOfItems_ShouldPopulateBuffer(byte[] streamContent, int bufferSize)
     {
+        using var cts = new CancellationTokenSource(TimeSpan.FromMilliseconds(50));
         using var stream = new MemoryStream(streamContent);
         var buffer = new byte[bufferSize];
 
-        await stream.PopulateAsync(buffer);
+        await stream.PopulateAsync(buffer, cts.Token);
 
-        buffer.Should().Equal(streamContent.Take(bufferSize));
+        buffer.ShouldBe(streamContent.Take(bufferSize));
     }
 
     [Theory]
@@ -67,6 +69,6 @@ public class PopulateAsync
 
         Func<Task> action = async () => await stream.PopulateAsync(buffer);
 
-        await action.Should().ThrowAsync<EndOfStreamException>();
+        await action.ShouldThrowAsync<EndOfStreamException>();
     }
 }