documentation update

fixed seqid test, added timestamp extraction
base32 refactoring
2026-07-10 22:16:20 +04:00 · 2026-07-10 22:06:37 +04:00 · 2026-07-10 21:53:37 +04:00 · 2025-11-11 21:53:10 +04:00 · 2025-11-11 21:48:35 +04:00 · 2025-11-11 19:11:12 +04:00
31 changed files with 823 additions and 185 deletions
@@ -10,13 +10,16 @@ jobs:
  publish:
    runs-on: ubuntu-latest

+    env:
+      DOTNET_CLI_TELEMETRY_OPTOUT: true
+
    steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v5

    - name: Setup .NET
-      uses: https://github.com/actions/setup-dotnet@v3
+      uses: actions/setup-dotnet@v4
      with:
-        dotnet-version: 9.x
+        dotnet-version: 10.x

    - name: Restore dependencies
      run: dotnet restore Core/Core.csproj
@@ -6,6 +6,7 @@ on:
    tags-ignore:
      - '**'
    paths-ignore:
+      - 'LICENSE'
      - 'README.md'
      - '.gitea/workflows/publish-*.yaml'
  pull_request:
@@ -14,28 +15,47 @@ on:
 jobs:
  test:
    runs-on: ubuntu-latest
+    name: .NET tests
+
+    env:
+      DOTNET_CLI_TELEMETRY_OPTOUT: true

    steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v5

    - name: Setup .NET
-      uses: https://github.com/actions/setup-dotnet@v3
+      uses: https://github.com/actions/setup-dotnet@v4
      with:
-        dotnet-version: 9.x
+        dotnet-version: |
+          8.0.x
+          9.0.x
+          10.0.x

    - name: Restore dependencies
-      run: dotnet restore
+      run: dotnet restore --disable-parallel

-    - name: Build
-      run: dotnet build --no-restore
+    - name: Build .NET 10.0
+      run: dotnet build --no-restore --framework net10.0 --configuration Release ./Core.Tests/Core.Tests.csproj

-    - name: Test
-      run: dotnet test --no-build --verbosity normal --logger trx --results-directory "TestResults-9.x"
+    - name: Build .NET 9.0
+      run: dotnet build --no-restore --framework net9.0 --configuration Release ./Core.Tests/Core.Tests.csproj
+
+    - name: Build .NET 8.0
+      run: dotnet build --no-restore --framework net8.0 --configuration Release ./Core.Tests/Core.Tests.csproj
+
+    - name: Test .NET 10.0
+      run: dotnet run --no-build --framework net10.0 --configuration Release --project ./Core.Tests/Core.Tests.csproj -- -trx TestResults/results-net10.trx
+
+    - name: Test .NET 9.0
+      run: dotnet run --no-build --framework net9.0 --configuration Release --project ./Core.Tests/Core.Tests.csproj -- -trx TestResults/results-net9.trx
+
+    - name: Test .NET 8.0
+      run: dotnet run --no-build --framework net8.0 --configuration Release --project ./Core.Tests/Core.Tests.csproj -- -trx TestResults/results-net8.trx

    - name: Upload dotnet test results
      uses: actions/upload-artifact@v3
      with:
-        name: dotnet-results-9.x
-        path: TestResults-9.x
+        name: test-results
+        path: TestResults
        if: ${{ always() }}
        retention-days: 30
@@ -1,4 +1,7 @@
 {
-    "dotnet.defaultSolution": "JustDotNet.Core.sln",
-    "dotnetAcquisitionExtension.enableTelemetry": false
+    "dotnet.defaultSolution": "JustDotNet.Core.slnx",
+    "omnisharp.enableEditorConfigSupport": true,
+    "dotnetAcquisitionExtension.enableTelemetry": false,
+    "dotnet.testWindow.useTestingPlatformProtocol": true,
+    "dotnet.formatting.organizeImportsOnFormat": true
 }
@@ -3,11 +3,31 @@ namespace Just.Core.Tests.Base32Conversions;
 public class Decode
 {
    [Theory]
-    [InlineData(15243)]
-    [InlineData(812010)]
-    [InlineData(97331334)]
-    [InlineData(20354)]
-    public void WhenEncodedToString_ShouldBeDecodedToTheSameByteArray(int seed)
+    [InlineData(15243, Base32EncodeOptions.None)]
+    [InlineData(15243, Base32EncodeOptions.LowerCase)]
+    [InlineData(15243, Base32EncodeOptions.NoPadding)]
+    [InlineData(15243, Base32EncodeOptions.LowerCaseNoPadding)]
+    [InlineData(812010, Base32EncodeOptions.None)]
+    [InlineData(812010, Base32EncodeOptions.LowerCase)]
+    [InlineData(812010, Base32EncodeOptions.NoPadding)]
+    [InlineData(812010, Base32EncodeOptions.LowerCaseNoPadding)]
+    [InlineData(97331334, Base32EncodeOptions.None)]
+    [InlineData(97331334, Base32EncodeOptions.LowerCase)]
+    [InlineData(97331334, Base32EncodeOptions.NoPadding)]
+    [InlineData(97331334, Base32EncodeOptions.LowerCaseNoPadding)]
+    [InlineData(20354, Base32EncodeOptions.None)]
+    [InlineData(20354, Base32EncodeOptions.LowerCase)]
+    [InlineData(20354, Base32EncodeOptions.NoPadding)]
+    [InlineData(20354, Base32EncodeOptions.LowerCaseNoPadding)]
+    [InlineData(33409, Base32EncodeOptions.None)]
+    [InlineData(33409, Base32EncodeOptions.LowerCase)]
+    [InlineData(33409, Base32EncodeOptions.NoPadding)]
+    [InlineData(33409, Base32EncodeOptions.LowerCaseNoPadding)]
+    [InlineData(59113, Base32EncodeOptions.None)]
+    [InlineData(59113, Base32EncodeOptions.LowerCase)]
+    [InlineData(59113, Base32EncodeOptions.NoPadding)]
+    [InlineData(59113, Base32EncodeOptions.LowerCaseNoPadding)]
+    public void WhenEncodedToString_ShouldBeDecodedToTheSameByteArray(int seed, Base32EncodeOptions options)
    {
        var rng = new Random(seed);

@@ -16,25 +36,33 @@ public class Decode
            var testBytes = new byte[i];
            rng.NextBytes(testBytes);

-            var resultString = Base32.Encode(testBytes);
+            var resultString = Base32.Encode(testBytes, options);
            var resultBytes = Base32.Decode(resultString);

-            resultBytes.Should().BeEquivalentTo(testBytes);
+            resultBytes.ShouldBeEquivalentTo(testBytes);
        }
    }

    [Theory]
    [InlineData("FG4M3ZQM3TVWDMBUP5L7N7V3JS7KBM2E", new byte[] { 0x29, 0xb8, 0xcd, 0xe6, 0x0c, 0xdc, 0xeb, 0x61, 0xb0, 0x34, 0x7f, 0x57, 0xf6, 0xfe, 0xbb, 0x4c, 0xbe, 0xa0, 0xb3, 0x44, })]
+    [InlineData("fg4m3zqm3tvwdmbup5l7n7v3js7kbm2e", new byte[] { 0x29, 0xb8, 0xcd, 0xe6, 0x0c, 0xdc, 0xeb, 0x61, 0xb0, 0x34, 0x7f, 0x57, 0xf6, 0xfe, 0xbb, 0x4c, 0xbe, 0xa0, 0xb3, 0x44, })]
    [InlineData("WXYEOQUZULMCY6ZQTDOLTRUZZMKQ====", new byte[] { 0xb5, 0xf0, 0x47, 0x42, 0x99, 0xa2, 0xd8, 0x2c, 0x7b, 0x30, 0x98, 0xdc, 0xb9, 0xc6, 0x99, 0xcb, 0x15, })]
+    [InlineData("wxyeoquzulmcy6zqtdoltruzzmkq====", new byte[] { 0xb5, 0xf0, 0x47, 0x42, 0x99, 0xa2, 0xd8, 0x2c, 0x7b, 0x30, 0x98, 0xdc, 0xb9, 0xc6, 0x99, 0xcb, 0x15, })]
    [InlineData("2IO2HTALCXZWCBD2", new byte[] { 0xd2, 0x1d, 0xa3, 0xcc, 0x0b, 0x15, 0xf3, 0x61, 0x04, 0x7a, })]
    [InlineData("ZFXJMF5N", new byte[] { 0b11001001, 0b01101110, 0b10010110, 0b00010111, 0b10101101, })]
+    [InlineData("zfxjmf5n", new byte[] { 0b11001001, 0b01101110, 0b10010110, 0b00010111, 0b10101101, })]
    [InlineData("CPIKTMY=", new byte[] { 0b00010011, 0b11010000, 0b10101001, 0b10110011, })]
+    [InlineData("EFCDEAA=", new byte[] { 0x21, 0x44, 0x32, 0x00, })]
+    [InlineData("EFCDEAI=", new byte[] { 0x21, 0x44, 0x32, 0x01, })]
+    [InlineData("EFCDEAQ=", new byte[] { 0x21, 0x44, 0x32, 0x02, })]
+    [InlineData("EFCDEAY=", new byte[] { 0x21, 0x44, 0x32, 0x03, })]
+    [InlineData("EFCDEBA=", new byte[] { 0x21, 0x44, 0x32, 0x04, })]
    [InlineData("JVNJA===", new byte[] { 0b01001101, 0b01011010, 0b10010000, })]
    [InlineData("74OQ====", new byte[] { 0b11111111, 0b00011101, })]
    public void WhenCalledWithValidString_ShouldReturnValidByteArray(string str, byte[] expected)
    {
        var actualBytesArray = Base32.Decode(str);
-        actualBytesArray.Should().Equal(expected);
+        actualBytesArray.ShouldBe(expected);
    }

    [Theory]
@@ -44,7 +72,7 @@ public class Decode
    public void WhenCalledWithValidStringThatEndsWithPaddingSign_ShouldReturnValidByteArray(string testString, byte[] expected)
    {
        var actualBytesArray = Base32.Decode(testString);
-        actualBytesArray.Should().Equal(expected);
+        actualBytesArray.ShouldBe(expected);
    }

    [Theory]
@@ -54,19 +82,46 @@ public class Decode
    public void WhenCalledWithValidStringWithoutPaddingSign_ShouldReturnValidByteArray(string testString, byte[] expected)
    {
        var actualBytesArray = Base32.Decode(testString);
-        actualBytesArray.Should().Equal(expected);
+        actualBytesArray.ShouldBe(expected);
    }

    [Theory]
    [InlineData("  ")]
-    [InlineData("hg2515i3215")]
+    [InlineData("hg2515i3215q")]
    [InlineData("hg712)21")]
-    [InlineData("hg712f 21")]
-    [System.Diagnostics.CodeAnalysis.SuppressMessage("Performance", "CA1806:Do not ignore method results", Justification = "Test case")]
+    [InlineData("hg712f 211")]
+    [InlineData("AEBAGB^F")]
    public void WhenCalledWithNotValidString_ShouldThrowFormatException(string testString)
    {
-        Action action = () => Base32.Decode(testString);
-        action.Should().Throw<FormatException>();
+        Action action = () => _ = Base32.Decode(testString);
+        action.ShouldThrow<FormatException>()
+            .WithMessage("Provided string contains invalid characters.");
+    }
+
+    [Theory]
+    [InlineData("A")]
+    [InlineData("AAA")]
+    [InlineData("AAAAAA")]
+    [InlineData("AEBAGBAFA")]
+    [InlineData("AEBAGBAFAAA")]
+    [InlineData("AEBAGBAFAAAAAA")]
+    public void WhenCalledWithInvalidStringLength_ShouldThrowFormatException(string testString)
+    {
+        Action action = () => _ = Base32.Decode(testString);
+        action.ShouldThrow<FormatException>()
+            .WithMessage("Invalid Base32 string length.");
+    }
+
+    [Theory]
+    [InlineData("ABCDEFG")]
+    [InlineData("AAAAAAB")]
+    [InlineData("EFCDF5J")]
+    [InlineData("EFCDF5P")]
+    public void WhenCalledWithInvalidLastByteEncoding_ShouldThrowFormatException(string testString)
+    {
+        Action action = () => _ = Base32.Decode(testString);
+        action.ShouldThrow<FormatException>()
+            .WithMessage("Invalid Base32 string. Inconsistent tail bits.");
    }

    [Theory]
@@ -74,6 +129,28 @@ public class Decode
    [InlineData("")]
    public void WhenCalledWithNullString_ShouldReturnEmptyArray(string? testString)
    {
-        Base32.Decode(testString).Should().BeEmpty();
+        Base32.Decode(testString).ShouldBeEmpty();
+    }
+
+    [Theory]
+    [InlineData("====")]
+    [InlineData("============")]
+    public void WhenCalledWithOnlyPadding_ShouldReturnEmptyArray(string testString)
+    {
+        Base32.Decode(testString).ShouldBeEmpty();
+    }
+
+    [Theory]
+    [InlineData("AEBAGBAF", 1)]
+    [InlineData("AEBAGBAF", 2)]
+    [InlineData("AEBAGBAF", 3)]
+    [InlineData("AEBAGBAFAY", 5)]
+    [InlineData("AEBAGBAFAYDQ", 6)]
+    public void SpanTooSmall_ThrowsArgumentException(string input, int outputLength)
+    {
+        byte[] output = new byte[outputLength];
+        Action action = () => _ = Base32.Decode(input, output);
+        action.ShouldThrow<ArgumentException>()
+            .WithMessage("Decoded input can not fit in output span. (Parameter 'output')");
    }
 }
@@ -4,6 +4,7 @@ public class Encode
 {
    [Theory]
    [InlineData("TQ======")]
+    [InlineData("CE======")]
    [InlineData("3X3A====")]
    [InlineData("426G6===")]
    [InlineData("C3V3Y===")]
@@ -30,8 +31,10 @@ public class Encode
    {
        var resultBytes = Base32.Decode(testString);
        var resultString = Base32.Encode(resultBytes);
+        var resultStringLowerCase = Base32.Encode(resultBytes, Base32EncodeOptions.LowerCase);

-        resultString.Should().Be(testString);
+        resultString.ShouldBe(testString);
+        resultStringLowerCase.ShouldBe(testString.ToLowerInvariant());
    }

    [Theory]
@@ -47,7 +50,29 @@ public class Encode
    public void WhenCalledWithNotEmptyByteArray_ShouldReturnValidString(string expected, byte[] testArray)
    {
        var str = Base32.Encode(testArray);
-        str.Should().Be(expected);
+        var strLowerCase = Base32.Encode(testArray, Base32EncodeOptions.LowerCase);
+
+        str.ShouldBe(expected);
+        strLowerCase.ShouldBe(expected.ToLowerInvariant());
+    }
+
+    [Theory]
+    [InlineData("FG4M3ZQM3TVWDMBUP5L7N7V3JS7KBM2E", new byte[] { 0x29, 0xb8, 0xcd, 0xe6, 0x0c, 0xdc, 0xeb, 0x61, 0xb0, 0x34, 0x7f, 0x57, 0xf6, 0xfe, 0xbb, 0x4c, 0xbe, 0xa0, 0xb3, 0x44, })]
+    [InlineData("WXYEOQUZULMCY6ZQTDOLTRUZZMKQ", new byte[] { 0xb5, 0xf0, 0x47, 0x42, 0x99, 0xa2, 0xd8, 0x2c, 0x7b, 0x30, 0x98, 0xdc, 0xb9, 0xc6, 0x99, 0xcb, 0x15, })]
+    [InlineData("2IO2HTALCXZWCBD2AAAAAAAAAAAA", new byte[] { 0xd2, 0x1d, 0xa3, 0xcc, 0x0b, 0x15, 0xf3, 0x61, 0x04, 0x7a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, })]
+    [InlineData("2IO2HTALCXZWCBD2AAAAAAAA", new byte[] { 0xd2, 0x1d, 0xa3, 0xcc, 0x0b, 0x15, 0xf3, 0x61, 0x04, 0x7a, 0x00, 0x00, 0x00, 0x00, 0x00, })]
+    [InlineData("2IO2HTALCXZWCBD2", new byte[] { 0xd2, 0x1d, 0xa3, 0xcc, 0x0b, 0x15, 0xf3, 0x61, 0x04, 0x7a, })]
+    [InlineData("ZFXJMF5N", new byte[] { 0b11001001, 0b01101110, 0b10010110, 0b00010111, 0b10101101, })]
+    [InlineData("CPIKTMY", new byte[] { 0b00010011, 0b11010000, 0b10101001, 0b10110011, })]
+    [InlineData("JVNJA", new byte[] { 0b01001101, 0b01011010, 0b10010000,  })]
+    [InlineData("74OQ", new byte[] { 0b11111111, 0b00011101, })]
+    public void WhenCalledWithNotEmptyByteArray_ShouldReturnValidStringWithNoPadding(string expected, byte[] testArray)
+    {
+        var str = Base32.Encode(testArray, Base32EncodeOptions.NoPadding);
+        var strLowerCase = Base32.Encode(testArray, Base32EncodeOptions.NoPadding | Base32EncodeOptions.LowerCase);
+
+        str.ShouldBe(expected);
+        strLowerCase.ShouldBe(expected.ToLowerInvariant());
    }

    [Theory]
@@ -56,7 +81,7 @@ 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 +93,23 @@ 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']);
+    }
+
+    [Theory]
+    [InlineData(new byte[] { 1, 2, 3 }, 3)]
+    [InlineData(new byte[] { 1, 2, 3 }, 4)]
+    [InlineData(new byte[] { 1, 2, 3 }, 5)]
+    [InlineData(new byte[] { 1, 2, 3 }, 6)]
+    [InlineData(new byte[] { 1, 2, 3 }, 7)]
+    [InlineData(new byte[] { 1, 2, 3, 4, 5, 6 }, 15)]
+    [InlineData(new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 }, 23)]
+    public void SpanTooSmall_ThrowsArgumentException(byte[] input, int outputLength)
+    {
+        var output = new char[outputLength];
+        Action action = () => _ = Base32.Encode(input, output);
+        action.ShouldThrow<ArgumentException>()
+            .WithMessage("Encoded input can not fit in output span. (Parameter 'output')");
    }
 }
@@ -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();
    }
 }
@@ -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']);
    }
 }
@@ -1,10 +1,11 @@
 <Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
-    <TargetFramework>net9.0</TargetFramework>
+    <TargetFrameworks>net8.0;net9.0;net10.0</TargetFrameworks>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
-    
+    <OutputType>Exe</OutputType>
+
    <AssemblyName>Just.Core.Tests</AssemblyName>
    <RootNamespace>Just.Core.Tests</RootNamespace>

@@ -14,14 +15,9 @@
  </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="coverlet.collector" Version="6.0.4">
+    <PackageReference Include="Shouldly" Version="4.3.0" />
+    <PackageReference Include="xunit.v3" Version="3.2.2" />
+    <PackageReference Include="coverlet.collector" Version="10.0.1">
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
      <PrivateAssets>all</PrivateAssets>
    </PackageReference>
@@ -1,2 +1,2 @@
 global using Xunit;
-global using FluentAssertions;
+global using Shouldly;
@@ -0,0 +1,141 @@
+namespace Just.Core.Tests.GuidV8Tests;
+
+public class ExtractTimestamp
+{
+    [Fact]
+    public void RoundTrip_ShouldReturnOriginalTimestamp()
+    {
+        var original = new DateTime(2026, 7, 10, 21, 30, 0, DateTimeKind.Utc);
+
+        var guid = GuidV8.NewGuid(original, RngEntropy.Weak);
+        var extracted = GuidV8.ExtractTimestamp(guid);
+
+        extracted.ShouldBe(original);
+        extracted.Kind.ShouldBe(DateTimeKind.Utc);
+    }
+
+    [Fact]
+    public void RoundTrip_ShouldPreserve100MicrosecondPrecision()
+    {
+        // 100-microsecond precision: 1234567 * 100µs = 123456.7ms
+        var original = new DateTime(2024, 3, 15, 8, 45, 30, 123, DateTimeKind.Utc)
+            .AddTicks(4567); // sub-millisecond ticks
+
+        var guid = GuidV8.NewGuid(original, RngEntropy.Weak);
+        var extracted = GuidV8.ExtractTimestamp(guid);
+
+        // 123ms + 4567 ticks = 123ms + 456.7µs
+        // timestamp = (ticks since epoch) / 1000 (100µs units)
+        // Ticks: 123ms = 1,230,000 ticks; + 4,567 ticks = 1,234,567 ticks
+        // timestamp = 1,234,567 / 1000 = 1234 (truncates last 3 digits)
+        // recovered = 1234 * 1000 = 1,234,000 ticks = 123.4ms
+        // So the sub-100µs part (67 ticks) is lost
+        extracted.ShouldBe(new DateTime(2024, 3, 15, 8, 45, 30, 123, DateTimeKind.Utc)
+            .AddTicks(4000)); // 123.4ms
+    }
+
+    [Fact]
+    public void RoundTrip_UnixEpoch_ShouldReturnExactEpoch()
+    {
+        var original = DateTime.UnixEpoch;
+
+        var guid = GuidV8.NewGuid(original, RngEntropy.Weak);
+        var extracted = GuidV8.ExtractTimestamp(guid);
+
+        extracted.ShouldBe(original);
+    }
+
+    [Fact]
+    public void RoundTrip_PreUnixEpoch_ShouldThrowArgumentException()
+    {
+        // Negative timestamps cannot be encoded correctly because the uint casts
+        // in NewGuid corrupt the sign. The encoding should reject them.
+        var preEpoch = new DateTime(1969, 7, 20, 20, 17, 40, DateTimeKind.Utc);
+
+        Action act = () => GuidV8.NewGuid(preEpoch);
+
+        act.ShouldThrow<ArgumentException>();
+    }
+
+    [Fact]
+    public void RoundTrip_FarFuture_ShouldPreserveTimestamp()
+    {
+        // Year 2200 — well within 48-bit range
+        var original = new DateTime(2200, 1, 1, 0, 0, 0, DateTimeKind.Utc);
+
+        var guid = GuidV8.NewGuid(original, RngEntropy.Weak);
+        var extracted = GuidV8.ExtractTimestamp(guid);
+
+        extracted.ShouldBe(original);
+    }
+
+    [Fact]
+    public void ExtractTimestamp_WithStrongEntropy_ShouldStillRecoverTimestamp()
+    {
+        var original = new DateTime(2025, 12, 25, 10, 0, 0, DateTimeKind.Utc);
+
+        var guid = GuidV8.NewGuid(original, RngEntropy.Strong);
+        var extracted = GuidV8.ExtractTimestamp(guid);
+
+        extracted.ShouldBe(original);
+    }
+
+    [Fact]
+    public void NonV8Guid_ShouldThrowArgumentException()
+    {
+        var guid = Guid.NewGuid(); // UUID v4
+
+        Action act = () => GuidV8.ExtractTimestamp(guid);
+
+        act.ShouldThrow<ArgumentException>()
+            .WithMessage("The provided GUID is not a UUID v8 (version=4). (Parameter 'guid')");
+    }
+
+    [Fact]
+    public void GuidEmpty_ShouldThrowArgumentException()
+    {
+        Action act = () => GuidV8.ExtractTimestamp(Guid.Empty);
+
+        act.ShouldThrow<ArgumentException>()
+            .WithMessage("The provided GUID is not a UUID v8 (version=0). (Parameter 'guid')");
+    }
+
+    [Fact]
+    public void MultipleRoundTrips_ShouldAllMatch()
+    {
+        var baseTime = new DateTime(2020, 1, 1, 0, 0, 0, DateTimeKind.Utc);
+
+        for (int i = 0; i < 100; i++)
+        {
+            var original = baseTime.AddMinutes(i * 37 + 13); // varied intervals
+            var guid = GuidV8.NewGuid(original, RngEntropy.Weak);
+            var extracted = GuidV8.ExtractTimestamp(guid);
+
+            extracted.ShouldBe(original);
+        }
+    }
+
+    [Fact]
+    public void ExtractTimestamp_ThenNewGuid_ShouldProduceSortableSequence()
+    {
+        var t1 = new DateTime(2026, 5, 1, 0, 0, 0, DateTimeKind.Utc);
+        var t2 = t1.AddSeconds(1);
+        var t3 = t2.AddSeconds(1);
+
+        var g1 = GuidV8.NewGuid(t1, RngEntropy.Weak);
+        var g2 = GuidV8.NewGuid(t2, RngEntropy.Weak);
+        var g3 = GuidV8.NewGuid(t3, RngEntropy.Weak);
+
+        var extracted1 = GuidV8.ExtractTimestamp(g1);
+        var extracted2 = GuidV8.ExtractTimestamp(g2);
+        var extracted3 = GuidV8.ExtractTimestamp(g3);
+
+        extracted1.ShouldBe(t1);
+        extracted2.ShouldBe(t2);
+        extracted3.ShouldBe(t3);
+
+        // Verify they sort in order
+        new[] { g3, g1, g2 }.Order().ShouldBe([g1, g2, g3]);
+        new[] { extracted3, extracted1, extracted2 }.Order().ShouldBe([t1, t2, t3]);
+    }
+}
@@ -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));
    }
 }
@@ -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.");
    }

@@ -85,12 +86,12 @@ public class NextId
        var time = TestEpoch.AddMilliseconds(200);

        // Act & Assert
-        for (int i = 0; i < 255; i++)
+        for (int i = 0; i < 256; i++)
        {
-            _seqId.Next(time); // Exhauste sequence
+            _seqId.Next(time); // Use all 256 sequence values (0-255)
        }
-        Action act = () => _seqId.Next(time);
-        act.Should().Throw<IndexOutOfRangeException>()
+        Action act = () => _seqId.Next(time); // 257th call should throw
+        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]
@@ -119,22 +120,25 @@ public class NextId

        // Assert
        long randomPart = id & RandMask;
-        randomPart.Should().BeInRange(0, RandMask);
+        randomPart.ShouldBeInRange(0, RandMask);
    }

    [Fact]
    public void DefaultInstance_NextId_ShouldUseDefaultEpoch()
    {
        // Arrange
-        var now = DateTime.UtcNow;
-        var defaultEpoch = new DateTime(2025, 1, 1, 0, 0, 0, DateTimeKind.Utc);
-        long expectedTimestamp = (long)(now - defaultEpoch).TotalMilliseconds;
+        var now = new DateTime(2026, 6, 3, 21, 11, 1, DateTimeKind.Utc);
+        SeqId.Default.UnsafeReplaceDefaultTimeFactory(() => now);

        // Act
        long id = SeqId.NextId();

        // Assert
+        long expectedTimestamp = GetExpectedTimestamp(now);
+
        long timestampPart = (id >> TimestampShift) & TimestampMask;
-        timestampPart.Should().BeCloseTo(expectedTimestamp & TimestampMask, 1); // Mask handles overflow
+        timestampPart.ShouldBeInRange(expectedTimestamp, expectedTimestamp + 1);
+
+        static long GetExpectedTimestamp(DateTime now) => ((long)(now - SeqId.DefaultEpoch).TotalMilliseconds) & TimestampMask; // Mask handles overflow
    }
 }
@@ -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;
+    }
+}
@@ -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>();
    }
 }
@@ -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>();
    }
 }
@@ -1,28 +1,59 @@
 namespace Just.Core;

+/// <summary>
+/// Encoding options for <see cref="Base32.Encode(ReadOnlySpan{byte}, Base32EncodeOptions)"/>.
+/// </summary>
+[Flags]
+public enum Base32EncodeOptions
+{
+    /// <summary>Standard RFC 4648 encoding (uppercase with padding).</summary>
+    None = 0x00,
+    /// <summary>Use lowercase alphabet.</summary>
+    LowerCase = 0x01,
+    /// <summary>Omit padding characters.</summary>
+    NoPadding = 0x02,
+    /// <summary>Lowercase alphabet without padding (combines <see cref="LowerCase"/> | <see cref="NoPadding"/>).</summary>
+    LowerCaseNoPadding = 0x03,
+}
+
+/// <summary>
+/// RFC 4648 Base32 encoder/decoder with span-based APIs.
+/// Uses stack allocation for inputs up to <see cref="MaxBytesStack"/> bytes; heap allocation otherwise.
+/// </summary>
 public static class Base32
 {
+    /// <summary>RFC 4648 Base32 alphabet (uppercase A-Z, 2-7).</summary>
    public const string Alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
+    /// <summary>Lowercase variant of the RFC 4648 alphabet.</summary>
+    public const string AlphabetLower = "abcdefghijklmnopqrstuvwxyz234567";
+    /// <summary>Padding character (=).</summary>
    public const char Padding = '=';
+    /// <summary>Maximum input byte count that uses stack allocation instead of heap.</summary>
    public const int MaxBytesStack = 250;

+    /// <summary>
+    /// Encodes a byte span into a Base32 string.
+    /// </summary>
+    /// <param name="input">The bytes to encode.</param>
+    /// <param name="options">Encoding options (casing, padding). Defaults to standard RFC 4648.</param>
+    /// <returns>The Base32-encoded string.</returns>
    [Pure]
-    public static string Encode(ReadOnlySpan<byte> input)
+    public static string Encode(ReadOnlySpan<byte> input, Base32EncodeOptions options = Base32EncodeOptions.None)
    {
        if (input.IsEmpty) return string.Empty;

        int outLength = 8 * ((input.Length + 4) / 5);
-        Span<char> output = input.Length <= MaxBytesStack
-            ? stackalloc char[outLength]
-            : new char[outLength];
+        Span<char> output = input.Length > MaxBytesStack
+            ? new char[outLength]
+            : stackalloc char[outLength];

-        var size = Encode(input, output);
+        var size = Encode(input, output, options);

        return new string(output[..size]);
    }

    [Pure]
-    public static int Encode(ReadOnlySpan<byte> input, Span<char> output)
+    public static int Encode(ReadOnlySpan<byte> input, Span<char> output, Base32EncodeOptions options = Base32EncodeOptions.None)
    {
        if (input.IsEmpty) return 0;

@@ -34,25 +65,63 @@ public static class Base32

        output = output[..outputLength];

-        int i = 0;
-        ReadOnlySpan<char> alphabet = Alphabet;
+        ReadOnlySpan<char> alphabet = (options & Base32EncodeOptions.LowerCase) == Base32EncodeOptions.LowerCase
+            ? AlphabetLower
+            : Alphabet;
        Span<byte> alphabetKeys = stackalloc byte[8];

+        int i = 0;
        for (int offset = 0; offset < input.Length;)
        {
            alphabetKeys.Clear();
            int numCharsToOutput = GetNextGroup(input, ref offset, alphabetKeys);

-            output[i++] = (numCharsToOutput > 0) ? alphabet[alphabetKeys[0]] : Padding;
-            output[i++] = (numCharsToOutput > 1) ? alphabet[alphabetKeys[1]] : Padding;
-            output[i++] = (numCharsToOutput > 2) ? alphabet[alphabetKeys[2]] : Padding;
-            output[i++] = (numCharsToOutput > 3) ? alphabet[alphabetKeys[3]] : Padding;
-            output[i++] = (numCharsToOutput > 4) ? alphabet[alphabetKeys[4]] : Padding;
-            output[i++] = (numCharsToOutput > 5) ? alphabet[alphabetKeys[5]] : Padding;
-            output[i++] = (numCharsToOutput > 6) ? alphabet[alphabetKeys[6]] : Padding;
-            output[i++] = (numCharsToOutput > 7) ? alphabet[alphabetKeys[7]] : Padding;
+            output[i++] = alphabet[alphabetKeys[0]];
+            output[i++] = alphabet[alphabetKeys[1]];
+
+            if (numCharsToOutput < 3)
+            {
+                i = FillWithPadding(output, i, numCharsToOutput, options);
+                break;
+            }
+            output[i++] = alphabet[alphabetKeys[2]];
+            output[i++] = alphabet[alphabetKeys[3]];
+
+            if (numCharsToOutput < 5)
+            {
+                i = FillWithPadding(output, i, numCharsToOutput, options);
+                break;
+            }
+            output[i++] = alphabet[alphabetKeys[4]];
+
+            if (numCharsToOutput < 6)
+            {
+                i = FillWithPadding(output, i, numCharsToOutput, options);
+                break;
+            }
+            output[i++] = alphabet[alphabetKeys[5]];
+            output[i++] = alphabet[alphabetKeys[6]];
+
+            if (numCharsToOutput < 8)
+            {
+                i = FillWithPadding(output, i, numCharsToOutput, options);
+                break;
+            }
+            output[i++] = alphabet[alphabetKeys[7]];
        }
+
        return i;
+
+        static int FillWithPadding(Span<char> output, int i, int numCharsToOutput, Base32EncodeOptions options)
+        {
+            if ((options & Base32EncodeOptions.NoPadding) == Base32EncodeOptions.NoPadding)
+            {
+                return i;
+            }
+            var pad = 8 - numCharsToOutput;
+            output[i..(i+pad)].Fill(Padding);
+            return i + pad;
+        }
    }

    [Pure]
@@ -61,10 +130,10 @@ public static class Base32
        input = input.TrimEnd(Padding);
        if (input.IsEmpty) return [];

-        var outputLength = 5 * ((input.Length + 7) / 8);
-        Span<byte> output = outputLength <= MaxBytesStack
-            ? stackalloc byte[outputLength]
-            : new byte[outputLength];
+        var outputLength = 5 * input.Length / 8;
+        Span<byte> output = outputLength > MaxBytesStack
+            ? new byte[outputLength]
+            : stackalloc byte[outputLength];

        var size = Decode(input, output);

@@ -76,7 +145,13 @@ public static class Base32
    {
        input = input.TrimEnd(Padding);

-        var outputLength = 5 * ((input.Length + 7) / 8);
+        var rem = input.Length % 8;
+        if (rem == 1 || rem == 3 || rem == 6)
+        {
+            throw new FormatException("Invalid Base32 string length.");
+        }
+
+        var outputLength = 5 * input.Length / 8;
        if (output.Length < outputLength)
        {
            throw new ArgumentException("Decoded input can not fit in output span.", nameof(output));
@@ -85,9 +160,9 @@ public static class Base32
        output = output[..outputLength];
        output.Clear();

-        Span<char> inputspan = outputLength <= MaxBytesStack
-            ? stackalloc char[input.Length]
-            : new char[input.Length];
+        Span<char> inputspan = outputLength > MaxBytesStack
+            ? new char[input.Length]
+            : stackalloc char[input.Length];
        input.ToUpperInvariant(inputspan);

        int bitIndex = 0;
@@ -127,10 +202,17 @@ public static class Base32
                inputIndex++;
                bitIndex = 0;
            }
-            else if (inputIndex == input.Length -1) break;
+            else if (inputIndex == input.Length -1)
+            {
+                if ((byteIndex & ~(0x1f << (bitPos - bits))) > 0)
+                {
+                    throw new FormatException("Invalid Base32 string. Inconsistent tail bits.");
+                }
+                break;
+            }
        }

-        return outputIndex + (outputBits + 7) / 8;
+        return outputIndex;
    }

    // returns the number of bytes that were output
@@ -145,7 +227,8 @@ public static class Base32
            4 => 7,
            _ => 8,
        };
-        uint b1 = (offset < input.Length) ? input[offset++] : 0U;
+
+        uint b1 = input[offset++];
        uint b2 = (offset < input.Length) ? input[offset++] : 0U;
        uint b3 = (offset < input.Length) ? input[offset++] : 0U;
        uint b4 = (offset < input.Length) ? input[offset++] : 0U;
@@ -2,10 +2,15 @@ using System.Runtime.InteropServices;

 namespace Just.Core;

+/// <summary>
+/// URL-safe Base64 encoder/decoder for bytes, <see cref="long"/>, and <see cref="Guid"/>.
+/// Uses the standard Base64Url character set (- and _ instead of + and /), padding stripped by default.
+/// </summary>
 public static class Base64Url
 {
    private const char Padding = '=';

+    /// <summary>Decodes an 11-character Base64Url string into a <see cref="long"/>.</summary>
    [Pure] public static long DecodeLong(ReadOnlySpan<char> value)
    {
        ArgumentOutOfRangeException.ThrowIfNotEqual(value.Length, 11);
@@ -24,6 +29,7 @@ public static class Base64Url
        return MemoryMarshal.Read<long>(longBytes);
    }

+    /// <summary>Decodes a 22-character Base64Url string into a <see cref="Guid"/>.</summary>
    [Pure] public static Guid DecodeGuid(ReadOnlySpan<char> value)
    {
        ArgumentOutOfRangeException.ThrowIfNotEqual(value.Length, 22);
@@ -42,6 +48,7 @@ public static class Base64Url
        return new Guid(guidBytes);
    }

+    /// <summary>Decodes a Base64Url string into a byte array.</summary>
    [Pure] public static byte[] Decode(ReadOnlySpan<char> input)
    {
        if (input.IsEmpty) return [];
@@ -53,6 +60,7 @@ public static class Base64Url
        return output[..size].ToArray();
    }

+    /// <summary>Decodes a Base64Url string into a pre-allocated byte span. Returns the number of bytes written.</summary>
    [Pure] public static int Decode(ReadOnlySpan<char> value, Span<byte> output)
    {
        var padding = (4 - (value.Length & 3)) & 3;
@@ -72,6 +80,7 @@ public static class Base64Url
        return outputBytes;
    }

+    /// <summary>Encodes a <see cref="long"/> into an 11-character Base64Url string.</summary>
    [Pure] public static string Encode(in long id)
    {
        Span<byte> longBytes = stackalloc byte[8];
@@ -84,6 +93,7 @@ public static class Base64Url
        return new string(chars[..^1]);
    }

+    /// <summary>Encodes a <see cref="Guid"/> into a 22-character Base64Url string.</summary>
    [Pure] public static string Encode(in Guid id)
    {
        Span<byte> guidBytes = stackalloc byte[16];
@@ -96,6 +106,7 @@ public static class Base64Url
        return new string(chars[..^2]);
    }

+    /// <summary>Encodes a byte span into a Base64Url string.</summary>
    [Pure] public static string Encode(ReadOnlySpan<byte> input)
    {
        if (input.IsEmpty) return string.Empty;
@@ -107,6 +118,7 @@ public static class Base64Url
        return new string(output[..strlen]);
    }

+    /// <summary>Encodes a byte span into a pre-allocated char span. Returns the number of characters written.</summary>
    [Pure] public static int Encode(ReadOnlySpan<byte> input, Span<char> output)
    {
        if (input.IsEmpty) return 0;
@@ -1,9 +1,13 @@
 using System.Numerics;
 using System.Runtime.InteropServices;
-using Just.Core.Extensions;

 namespace Just.Core.Collections;

+/// <summary>
+/// A 2D grid with lazy min/max caching, cloning, and binary stream serialization.
+/// Requires <typeparamref name="T"/> to support comparison and equality operators.
+/// </summary>
+/// <typeparam name="T">The element type; must implement <c>IComparisonOperators&lt;T, T, bool&gt;</c> and <c>IEqualityOperators&lt;T, T, bool&gt;</c>.</typeparam>
 public class DataMap<T> : Map<T>, IDataMap<T>, ICloneable
    where T : IComparisonOperators<T, T, bool>, IEqualityOperators<T, T, bool>
 {
@@ -122,14 +126,14 @@ public static class DataMap
        where T : unmanaged, IComparisonOperators<T, T, bool>, IEqualityOperators<T, T, bool>
    {
        byte[] headBytes = new byte[HeaderSize];
-        await stream.PopulateAsync(headBytes, cancellationToken);
+        await stream.ReadExactlyAsync(headBytes, cancellationToken);
        var head = MemoryMarshal.Read<Header>(headBytes);

        var bodySize = DataMap<T>.ElementSize * head.Width * head.Height;
        if (bodySize != head.BodySize) throw new InvalidOperationException("Can not read DataMap. Element size mismatch.");

        byte[] bodyBytes = new byte[bodySize];
-        await stream.PopulateAsync(bodyBytes, cancellationToken);
+        await stream.ReadExactlyAsync(bodyBytes, cancellationToken);

        T[] body = MemoryMarshal.Cast<byte, T>(bodyBytes).ToArray();
        return new DataMap<T>((int)head.Width, (int)head.Height, body);
@@ -157,7 +161,7 @@ public static class DataMap
    {
        Header head = default;
        var headSpan = MemoryMarshal.AsBytes(MemoryMarshal.CreateSpan(ref head, 1));
-        stream.Populate(headSpan);
+        stream.ReadExactly(headSpan);

        var bodySize = DataMap<T>.ElementSize * head.Width * head.Height;
        if (bodySize != head.BodySize) throw new InvalidOperationException("Can not read DataMap. Element size mismatch.");
@@ -165,7 +169,7 @@ public static class DataMap
        T[] body = new T[bodySize];
        var bodySpan = MemoryMarshal.AsBytes(body.AsSpan());

-        stream.Populate(bodySpan);
+        stream.ReadExactly(bodySpan);
        
        return new DataMap<T>((int)head.Width, (int)head.Height, body);
    }
@@ -2,6 +2,8 @@ using System.Numerics;

 namespace Just.Core.Collections;

+/// <summary>Read-only interface for a 2D grid with min/max tracking and cloning.</summary>
+/// <typeparam name="T">The element type; must support comparison and equality operators.</typeparam>
 public interface IDataMap<T> : IMap<T>, ICloneable
    where T : IComparisonOperators<T, T, bool>, IEqualityOperators<T, T, bool>
 {
@@ -1,5 +1,7 @@
 namespace Just.Core.Collections;

+/// <summary>Read-only interface for a 2D grid with coordinate-based access and enumeration.</summary>
+/// <typeparam name="T">The type of elements in the map.</typeparam>
 public interface IMap<T> : IReadOnlyCollection<MapPoint<T>>
 {
    int Width { get; }
@@ -3,6 +3,22 @@ using System.Collections.Immutable;

 namespace Just.Core.Collections;

+/// <summary>
+/// Represents an immutable, ordered sequence of items with value‑equality semantics.
+/// </summary>
+/// <typeparam name="T">The type of elements in the sequence.</typeparam>
+/// <remarks>
+/// <para>
+/// This class is a thin wrapper around <see cref="ImmutableList{T}"/> that implements
+/// <see cref="IReadOnlyList{T}"/>, <see cref="IEquatable{T}"/>, and value‑based equality.
+/// All modifications return new <see cref="ImmutableSequence{T}"/> instances, leaving the
+/// original unchanged.
+/// </para>
+/// <para>
+/// Subclasses may override <see cref="ConstructNew"/> to ensure mutation methods return
+/// the correct derived type.
+/// </para>
+/// </remarks>
 public class ImmutableSequence<T> :
    IEnumerable<T>,
    IReadOnlyList<T>,
@@ -11,17 +27,61 @@ public class ImmutableSequence<T> :
    private static readonly Func<T?, T?, bool> CompareItem = EqualityComparer<T>.Default.Equals;
    private readonly ImmutableList<T> _values;

+    /// <summary>
+    /// Initializes a new empty instance of the <see cref="ImmutableSequence{T}"/> class.
+    /// </summary>
    public ImmutableSequence() => _values = [];
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ImmutableSequence{T}"/> class that
+    /// wraps the specified <see cref="ImmutableList{T}"/>.
+    /// </summary>
+    /// <param name="values">The immutable list to wrap.</param>
    public ImmutableSequence(ImmutableList<T> values) => _values = values;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ImmutableSequence{T}"/> class with
+    /// the elements from the provided enumerable sequence.
+    /// </summary>
+    /// <param name="values">The items to include in the sequence.</param>
    public ImmutableSequence(IEnumerable<T> values) => _values = [..values];
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ImmutableSequence{T}"/> class with
+    /// the elements from the provided read‑only span.
+    /// </summary>
+    /// <param name="values">The items to include in the sequence.</param>
    public ImmutableSequence(ReadOnlySpan<T> values) : this(ImmutableList.Create(values))
    {
    }

+    /// <summary>
+    /// Gets a value indicating whether the sequence contains any elements.
+    /// </summary>
    public bool IsEmpty => _values.IsEmpty;
+
+    /// <summary>
+    /// Gets the number of elements in the sequence.
+    /// </summary>
    public int Count => _values.Count;
+
+    /// <summary>
+    /// Gets the element at the specified zero‑based index.
+    /// </summary>
+    /// <param name="index">The zero‑based index of the element to get.</param>
+    /// <returns>The element at the specified index.</returns>
    public T this[int index] => _values[index];
+    /// <summary>
+    /// Gets the element at the specified position from the start or end of the sequence.
+    /// </summary>
+    /// <param name="index">An <see cref="Index"/> value (e.g., <c>^1</c> for the last element).</param>
+    /// <returns>The element at the specified position.</returns>
    public T this[Index index] => _values[index];
+    /// <summary>
+    /// Gets a new <see cref="ImmutableSequence{T}"/> containing the elements in the specified range.
+    /// </summary>
+    /// <param name="range">The range of elements to include.</param>
+    /// <returns>A new sequence representing the slice.</returns>
    public ImmutableSequence<T> this[Range range]
    {
        get
@@ -31,25 +91,60 @@ public class ImmutableSequence<T> :
        }
    }

+    /// <summary>
+    /// Creates a new <see cref="ImmutableSequence{T}"/> from the provided immutable list.
+    /// Subclasses can override this to return instances of a more specific type.
+    /// </summary>
+    /// <param name="values">The immutable list that will become the internal storage.</param>
+    /// <returns>A new sequence containing the given items.</returns>
    protected virtual ImmutableSequence<T> ConstructNew(ImmutableList<T> values) => [..values];

+    /// <summary>
+    /// Returns a new sequence with the specified value appended to the end.
+    /// </summary>
+    /// <param name="value">The value to add.</param>
+    /// <returns>A new sequence containing the original items followed by <paramref name="value"/>.</returns>
    public ImmutableSequence<T> Add(T value) => ConstructNew(_values.Add(value));
+    /// <summary>
+    /// Returns a new sequence with the specified value inserted at the beginning.
+    /// </summary>
+    /// <param name="value">The value to add.</param>
+    /// <returns>A new sequence that starts with <paramref name="value"/> and then contains the original items.</returns>
    public ImmutableSequence<T> AddFront(T value) => ConstructNew(_values.Insert(0, value));

+    /// <summary>
+    /// Returns an enumerator that iterates through the sequence.
+    /// </summary>
+    /// <returns>A <see cref="ImmutableList{T}.Enumerator"/> value type enumerator.</returns>
    public ImmutableList<T>.Enumerator GetEnumerator() => _values.GetEnumerator();
    IEnumerator<T> IEnumerable<T>.GetEnumerator() => ((IEnumerable<T>)_values).GetEnumerator();
    IEnumerator IEnumerable.GetEnumerator() => ((IEnumerable)_values).GetEnumerator();

    public override string ToString() => string.Join(Environment.NewLine, _values);

+    /// <summary>
+    /// Determines whether this sequence is equal to another <see cref="ImmutableSequence{T}"/>.
+    /// Equality is based on the number of elements and the element‑wise equality comparison
+    /// using the default equality comparer for <typeparamref name="T"/>.
+    /// </summary>
+    /// <param name="other">The sequence to compare with this instance. Can be <c>null</c>.</param>
+    /// <returns>
+    /// <c>true</c> if the sequences have the same length and all elements are equal;
+    /// <c>false</c> otherwise.
+    /// </returns>
    public virtual bool Equals([NotNullWhen(true)] ImmutableSequence<T>? other)
    {
+        if (other is null)
+        {
+            return false;
+        }
+
        if (ReferenceEquals(this, other))
        {
            return true;
        }

-        if (_values.Count != other?._values.Count)
+        if (_values.Count != other._values.Count)
        {
            return false;
        }
@@ -65,7 +160,16 @@ public class ImmutableSequence<T> :
        return true;
    }

+    /// <summary>
+    /// Determines whether the specified object is equal to the current sequence.
+    /// </summary>
+    /// <param name="obj">The object to compare with the current sequence.</param>
+    /// <returns><c>true</c> if <paramref name="obj"/> is an <see cref="ImmutableSequence{T}"/> and equals this instance; otherwise <c>false</c>.</returns>
    public override bool Equals([NotNullWhen(true)] object? obj) => Equals(obj as ImmutableSequence<T>);
+    /// <summary>
+    /// Serves as a hash function for the sequence.
+    /// </summary>
+    /// <returns>A hash code that incorporates all elements in order.</returns>
    public override int GetHashCode()
    {
        HashCode hash = new();
@@ -78,6 +182,18 @@ public class ImmutableSequence<T> :
        return hash.ToHashCode();
    }

+    /// <summary>
+    /// Determines whether two sequences are equal.
+    /// </summary>
+    /// <param name="left">The first sequence to compare.</param>
+    /// <param name="right">The second sequence to compare.</param>
+    /// <returns><c>true</c> if both sequences are <c>null</c> or they are considered equal; otherwise <c>false</c>.</returns>
    public static bool operator ==(ImmutableSequence<T>? left, ImmutableSequence<T>? right) => left is null ? right is null : left.Equals(right);
+    /// <summary>
+    /// Determines whether two sequences are not equal.
+    /// </summary>
+    /// <param name="left">The first sequence to compare.</param>
+    /// <param name="right">The second sequence to compare.</param>
+    /// <returns><c>true</c> if the sequences are not equal; otherwise <c>false</c>.</returns>
    public static bool operator !=(ImmutableSequence<T>? left, ImmutableSequence<T>? right) => !(left == right);
 }
@@ -2,6 +2,11 @@ using System.Collections;

 namespace Just.Core.Collections;

+/// <summary>
+/// A 2D grid container providing indexer access, enumeration as <see cref="MapPoint{T}"/> values,
+/// and conversion to a 2D array. Coordinates are clamped to valid ranges.
+/// </summary>
+/// <typeparam name="T">The type of elements in the map.</typeparam>
 public class Map<T> : IMap<T>
 {
    internal readonly T[] _values;
@@ -68,8 +73,8 @@ public class Map<T> : IMap<T>
    {
        get
        {
-            x = Math.Clamp(x, 0, Width);
-            y = Math.Clamp(y, 0, Height);
+            x = Math.Clamp(x, 0, Width - 1);
+            y = Math.Clamp(y, 0, Height - 1);
            return ref _values[(y * Width) + x];
        }
    }
@@ -1,5 +1,7 @@
 namespace Just.Core.Collections;

+/// <summary>A value and its coordinates within a <see cref="IMap{T}"/>.</summary>
+/// <typeparam name="T">The type of the map element.</typeparam>
 public readonly struct MapPoint<T>(T value, int x, int y, IMap<T> map)
 {
    public readonly T Value = value;
@@ -1,16 +1,18 @@
 <Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
-    <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
+    <TargetFrameworks>net8.0;net9.0;net10.0</TargetFrameworks>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
    <AssemblyName>Just.Core</AssemblyName>
    <RootNamespace>Just.Core</RootNamespace>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+    <NoWarn>$(NoWarn);CS1591</NoWarn>

    <Description>Small .Net library with useful helper classes, functions and extensions.</Description>
    <PackageTags>extensions;helpers;helper-functions</PackageTags>
    <Authors>JustFixMe</Authors>
-    <Copyright>Copyright (c) 2023-2025 JustFixMe</Copyright>
+    <Copyright>Copyright (c) 2023-2026 JustFixMe</Copyright>
    <PackageLicenseFile>LICENSE</PackageLicenseFile>
    <PackageReadmeFile>README.md</PackageReadmeFile>
    <RepositoryUrl>https://github.com/JustFixMe/Just.Core/</RepositoryUrl>
@@ -3,6 +3,7 @@ namespace Just.Core.Extensions;
 /// <summary>
 /// Provides extension methods for <see cref="Stream"/> to fully populate buffers.
 /// </summary>
+[Obsolete("Stream.ReadExactly and Stream.ReadExactlyAsync have the same functionality. Will be removed in the next version.")]
 public static class SystemIOStreamExtensions
 {
    /// <summary>
@@ -16,6 +17,7 @@ public static class SystemIOStreamExtensions
    /// <exception cref="ArgumentOutOfRangeException">Thrown when <paramref name="offset"/> or <paramref name="length"/> is invalid</exception>
    /// <exception cref="EndOfStreamException">Thrown if the stream ends before filling the buffer</exception>
    /// <exception cref="IOException">Thrown for I/O errors during reading</exception>
+    [Obsolete("Stream.ReadExactly and Stream.ReadExactlyAsync have the same functionality. Will be removed in the next version.")]
    public static void Populate(this Stream stream, byte[] buffer, int offset, int length)
        => stream.Populate(buffer.AsSpan(offset, length));
    /// <summary>
@@ -26,6 +28,7 @@ public static class SystemIOStreamExtensions
    /// <exception cref="ArgumentNullException">Thrown when <paramref name="stream"/> is null</exception>
    /// <exception cref="EndOfStreamException">Thrown if the stream ends before filling the buffer</exception>
    /// <exception cref="IOException">Thrown for I/O errors during reading</exception>
+    [Obsolete("Stream.ReadExactly and Stream.ReadExactlyAsync have the same functionality. Will be removed in the next version.")]
    public static void Populate(this Stream stream, byte[] buffer)
        => stream.Populate(buffer.AsSpan());
    /// <summary>
@@ -36,6 +39,7 @@ public static class SystemIOStreamExtensions
    /// <exception cref="ArgumentNullException">Thrown when <paramref name="stream"/> is null</exception>
    /// <exception cref="EndOfStreamException">Thrown if the stream ends before filling the buffer</exception>
    /// <exception cref="IOException">Thrown for I/O errors during reading</exception>
+    [Obsolete("Stream.ReadExactly and Stream.ReadExactlyAsync have the same functionality. Will be removed in the next version.")]
    public static void Populate(this Stream stream, Span<byte> buffer)
    {
        ArgumentNullException.ThrowIfNull(stream);
@@ -64,6 +68,7 @@ public static class SystemIOStreamExtensions
    /// <exception cref="EndOfStreamException">Thrown if the stream ends before filling the buffer</exception>
    /// <exception cref="OperationCanceledException">Thrown if canceled via cancellation token</exception>
    /// <exception cref="IOException">Thrown for I/O errors during reading</exception>
+    [Obsolete("Stream.ReadExactly and Stream.ReadExactlyAsync have the same functionality. Will be removed in the next version.")]
    public static ValueTask PopulateAsync(this Stream stream, byte[] buffer, CancellationToken cancellationToken = default)
        => stream.PopulateAsync(buffer.AsMemory(), cancellationToken);
    /// <summary>
@@ -80,6 +85,7 @@ public static class SystemIOStreamExtensions
    /// <exception cref="EndOfStreamException">Thrown if the stream ends before filling the buffer</exception>
    /// <exception cref="OperationCanceledException">Thrown if canceled via cancellation token</exception>
    /// <exception cref="IOException">Thrown for I/O errors during reading</exception>
+    [Obsolete("Stream.ReadExactly and Stream.ReadExactlyAsync have the same functionality. Will be removed in the next version.")]
    public static ValueTask PopulateAsync(this Stream stream, byte[] buffer, int offset, int length, CancellationToken cancellationToken = default)
        => stream.PopulateAsync(buffer.AsMemory(offset, length), cancellationToken);
    /// <summary>
@@ -93,6 +99,7 @@ public static class SystemIOStreamExtensions
    /// <exception cref="EndOfStreamException">Thrown if the stream ends before filling the buffer</exception>
    /// <exception cref="OperationCanceledException">Thrown if canceled via cancellation token</exception>
    /// <exception cref="IOException">Thrown for I/O errors during reading</exception>
+    [Obsolete("Stream.ReadExactly and Stream.ReadExactlyAsync have the same functionality. Will be removed in the next version.")]
    public static async ValueTask PopulateAsync(this Stream stream, Memory<byte> buffer, CancellationToken cancellationToken = default)
    {
        ArgumentNullException.ThrowIfNull(stream);
@@ -1,12 +1,14 @@
+using System.Runtime.InteropServices;
 using System.Security.Cryptography;

 namespace Just.Core;

 public static class GuidV8
 {
-    private const long TicksPrecision = TimeSpan.TicksPerMillisecond / 10;
+    private const long TicksPrecision = TimeSpan.TicksPerMillisecond / 10; // 100-microsecond units

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    [ExcludeFromCodeCoverage]
    public static Guid NewGuid(RngEntropy entropy = RngEntropy.Strong) => NewGuid(DateTime.UtcNow, entropy);

    public static Guid NewGuid(DateTime dateTime, RngEntropy entropy = RngEntropy.Strong)
@@ -14,6 +16,12 @@ public static class GuidV8
        var epoch = dateTime.Subtract(DateTime.UnixEpoch);
        var timestamp = epoch.Ticks / TicksPrecision;

+        // Negative timestamps can't be encoded correctly due to unsigned bit operations
+        if (timestamp < 0)
+        {
+            throw new ArgumentException("Timestamp must be on or after UnixEpoch (1970-01-01 UTC).", nameof(dateTime));
+        }
+
        uint tsHigh = (uint)((timestamp >> 16) & 0xFFFFFFFF);
        ushort tsLow = (ushort)(timestamp & 0x0000FFFF);

@@ -39,4 +47,37 @@ public static class GuidV8
            version,
            bytes[2], bytes[3], bytes[4], bytes[5], bytes[6], bytes[7], bytes[8], bytes[9]);
    }
+
+    /// <summary>
+    /// Extracts the timestamp from a UUID v8 generated by <see cref="NewGuid(DateTime, RngEntropy)"/>.
+    /// </summary>
+    /// <param name="guid">The UUID v8 to extract the timestamp from.</param>
+    /// <returns>The <see cref="DateTime"/> (UTC) encoded in the GUID's timestamp fields.</returns>
+    /// <exception cref="ArgumentException">
+    /// Thrown if <paramref name="guid"/> is not a UUID v8.
+    /// </exception>
+    /// <remarks>
+    /// The returned timestamp has 100-microsecond precision (the resolution used by
+    /// <see cref="NewGuid(DateTime, RngEntropy)"/>). Sub-100µs components of the original
+    /// <see cref="DateTime"/> are not recoverable.
+    /// </remarks>
+    [Pure]
+    public static DateTime ExtractTimestamp(Guid guid)
+    {
+        Span<byte> bytes = stackalloc byte[16];
+        guid.TryWriteBytes(bytes);
+
+        // Version is the high nibble of byte 7 (parameter 'c' high byte, little-endian byte 7)
+        var version = bytes[7] >> 4;
+        if (version != 8)
+            throw new ArgumentException($"The provided GUID is not a UUID v8 (version={version}).", nameof(guid));
+
+        // tsHigh is stored as Int32 at bytes 0-3
+        uint tsHigh = MemoryMarshal.Read<uint>(bytes);
+        // tsLow is stored as Int16 at bytes 4-5
+        ushort tsLow = MemoryMarshal.Read<ushort>(bytes[4..]);
+
+        long timestamp = ((long)tsHigh << 16) | tsLow;
+        return DateTime.UnixEpoch.AddTicks(timestamp * TicksPrecision);
+    }
 }
@@ -48,10 +48,10 @@ public sealed class SeqId(DateTime epoch)
    /// <param name="entropy">Entropy quality (default: Strong)</param>
    /// <returns>64-bit sequential ID with random component</returns>
    /// <exception cref="IndexOutOfRangeException">
-    /// Thrown if more than 255 IDs generated in 1ms
+    /// Thrown if more than 256 IDs generated in 1ms
    /// </exception>
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public static long NextId(RngEntropy entropy = RngEntropy.Strong) => Default.Next(DateTime.UtcNow, entropy);
+    public static long NextId(RngEntropy entropy = RngEntropy.Strong) => Default.Next(entropy);

 #if NET9_0_OR_GREATER
    private readonly Lock _lock = new();
@@ -62,6 +62,7 @@ public sealed class SeqId(DateTime epoch)
    private readonly DateTime _epoch = epoch;
    private int _seqId = 0;
    private long _lastTimestamp = -1L;
+    private Func<DateTime> _defaultTimeFactory = static () => DateTime.UtcNow;

    /// <summary>
    /// Generates next ID using current UTC time
@@ -69,10 +70,10 @@ public sealed class SeqId(DateTime epoch)
    /// <param name="entropy">Entropy quality (default: Strong)</param>
    /// <returns>64-bit sequential ID with random component</returns>
    /// <exception cref="IndexOutOfRangeException">
-    /// Thrown if more than 255 IDs generated in 1ms
+    /// Thrown if more than 256 IDs generated in 1ms
    /// </exception>
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public long Next(RngEntropy entropy = RngEntropy.Strong) => Next(DateTime.UtcNow, entropy);
+    public long Next(RngEntropy entropy = RngEntropy.Strong) => Next(_defaultTimeFactory(), entropy);

    /// <summary>
    /// Generates next ID with explicit timestamp
@@ -84,7 +85,7 @@ public sealed class SeqId(DateTime epoch)
    /// Thrown if <paramref name="dateTime"/> is earlier than last used timestamp
    /// </exception>
    /// <exception cref="IndexOutOfRangeException">
-    /// Thrown if more than 255 IDs generated in 1ms
+    /// Thrown if more than 256 IDs generated in 1ms
    /// </exception>
    public long Next(DateTime dateTime, RngEntropy entropy = RngEntropy.Strong)
    {
@@ -104,7 +105,7 @@ public sealed class SeqId(DateTime epoch)
                throw new InvalidOperationException("Refused to create new SeqId. Last timestamp is in the future.");
            }

-            if (_seqId == SeqMask)
+            if (_seqId > SeqMask)
            {
                throw new IndexOutOfRangeException("Refused to create new SeqId. Sequence exhausted.");
            }
@@ -118,4 +119,6 @@ public sealed class SeqId(DateTime epoch)

        return timestamp | currentSeq | currentRand;
    }
+
+    internal void UnsafeReplaceDefaultTimeFactory(Func<DateTime> timeFactory) => _defaultTimeFactory = timeFactory;
 }
@@ -1,28 +0,0 @@
-
-Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 17
-VisualStudioVersion = 17.0.31903.59
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Core", "Core\Core.csproj", "{C709D8C9-FE18-4B70-ABE0-57A1850C3398}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Core.Tests", "Core.Tests\Core.Tests.csproj", "{CBA236E8-5CAC-4587-AD7C-A480CD998EB8}"
-EndProject
-Global
-	GlobalSection(SolutionConfigurationPlatforms) = preSolution
-		Debug|Any CPU = Debug|Any CPU
-		Release|Any CPU = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
-	EndGlobalSection
-	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{C709D8C9-FE18-4B70-ABE0-57A1850C3398}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{C709D8C9-FE18-4B70-ABE0-57A1850C3398}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{C709D8C9-FE18-4B70-ABE0-57A1850C3398}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{C709D8C9-FE18-4B70-ABE0-57A1850C3398}.Release|Any CPU.Build.0 = Release|Any CPU
-		{CBA236E8-5CAC-4587-AD7C-A480CD998EB8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{CBA236E8-5CAC-4587-AD7C-A480CD998EB8}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{CBA236E8-5CAC-4587-AD7C-A480CD998EB8}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{CBA236E8-5CAC-4587-AD7C-A480CD998EB8}.Release|Any CPU.Build.0 = Release|Any CPU
-	EndGlobalSection
-EndGlobal
@@ -0,0 +1,4 @@
+<Solution>
+  <Project Path="Core.Tests/Core.Tests.csproj" />
+  <Project Path="Core/Core.csproj" />
+</Solution>
@@ -1,4 +1,4 @@
-Copyright (c) 2023-2025 JustFixMe
+Copyright (c) 2023-2026 JustFixMe

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -1,18 +1,92 @@
-# .Net library with helpers, functions and extensions
+# Just.Core

-Just some stuff that is used in different projects...
+Small .NET library with useful helper classes, functions, and extensions — stuff used across multiple projects.
+
+[![NuGet](https://img.shields.io/nuget/v/Just.Core)](https://www.nuget.org/packages/Just.Core)
+
+## Install
+
+```sh
+dotnet add package Just.Core
+```

 ## Features

- ```Map``` and ```DataMap``` collection types
- Extensions for ```System.String``` and ```System.IO.Stream```
- Small converters for **Base32** and **Base64Url** encodings
-  
-## Getting Started
+### Encoding

-### Install from NuGet.org
+**Base32** — RFC 4648 encoder/decoder with lowercase and no-padding options.

-```sh
-# install the package using NuGet
-dotnet add package Just.Core
+```csharp
+var encoded = Base32.Encode(bytes);                           // "ABCDEFGH..."
+var encoded = Base32.Encode(bytes, Base32EncodeOptions.LowerCaseNoPadding);
+var bytes   = Base32.Decode("ABCDEFGH...");
 ```
+
+**Base64Url** — URL-safe Base64 for bytes, `long`, and `Guid`.
+
+```csharp
+var str  = Base64Url.Encode(myGuid);           // "5QrdUxDUVkCAEGw8pvLsEw"
+var guid = Base64Url.DecodeGuid(str);
+var str  = Base64Url.Encode(123456789L);       // "7NcVAAAAAA"
+var val  = Base64Url.DecodeLong(str);
+```
+
+### IDs
+
+**SeqId** — Time-based 64-bit sequential ID with configurable entropy. Thread-safe.
+
+```csharp
+var id = SeqId.NextId();                       // default instance, Strong entropy
+var id = SeqId.NextId(RngEntropy.Weak);        // faster, less collision-resistant
+
+// Custom epoch
+var generator = new SeqId(new DateTime(2024, 1, 1, 0, 0, 0, DateTimeKind.Utc));
+var id = generator.Next();
+```
+
+Structure: `[1 bit reserved][41 bits ms since epoch][8 bits sequence][14 bits random]`
+
+**GuidV8** — Time-sortable UUID v8 with extractable timestamp.
+
+```csharp
+var guid = GuidV8.NewGuid();                   // current UTC, Strong entropy
+var guid = GuidV8.NewGuid(specificTime);
+var when = GuidV8.ExtractTimestamp(guid);      // recover timestamp (100µs precision)
+```
+
+### Collections
+
+**Map&lt;T&gt; / DataMap&lt;T&gt;** — 2D grid container with indexing, enumeration, and min/max.
+
+```csharp
+var map = new Map<int>(width: 10, height: 10, values);
+var value = map[3, 5];                         // integer or double coordinates
+var point = map.Get(3.5, 5.2);                 // MapPoint<T> with position metadata
+
+var dmap = new DataMap<double>(values, 10, 10);
+var min = dmap.Min;                            // MapPoint<double> — cached
+var max = dmap.Max;                            // lazy, thread-safe on first access
+
+// Stream serialization (sync + async)
+dmap.WriteToStream(stream);
+var copy = DataMap.ReadFromStream<double>(stream);
+```
+
+**ImmutableSequence&lt;T&gt;** — Immutable list with structural value equality.
+
+```csharp
+var seq = new ImmutableSequence<int>([1, 2, 3]);
+var seq2 = seq.Add(4);                         // new instance, seq unchanged
+seq == seq2;                                   // false — 3 vs 4 elements
+new ImmutableSequence<int>([1, 2, 3]) == seq;  // true — value equality
+```
+
+## Supported Targets
+
+- .NET 8.0 (LTS)
+- .NET 9.0
+- .NET 10.0
+
+## License
+
+MIT — see [LICENSE](LICENSE).
Author	SHA1	Message	Date
just	e37e9b65c3	documentation update .NET Test / .NET tests (push) Successful in 1m58s Details .NET Publish / publish (push) Successful in 58s Details	2026-07-10 22:16:20 +04:00
just	8e961352d2	fixed seqid test, added timestamp extraction .NET Test / .NET tests (push) Successful in 1m55s Details	2026-07-10 22:06:37 +04:00
just	566c813e8d	base32 refactoring .NET Test / .NET tests (push) Failing after 1m54s Details	2026-07-10 21:53:37 +04:00
just	d11c74e5d6	setup multiple dotnet versions .NET Test / .NET tests (push) Successful in 2m44s Details .NET Publish / publish (push) Successful in 51s Details	2025-11-11 21:53:10 +04:00
just	85721b9769	added net10.0 support .NET Test / .NET tests (push) Failing after 1m0s Details	2025-11-11 21:48:35 +04:00
just	f7484b35e2	test pipeline tweaks .NET Test / .NET 8.0 (push) Failing after 11m49s Details .NET Test / .NET 9.0 (push) Successful in 12m3s Details	2025-11-11 19:11:12 +04:00
just	a490a9b328	fix dotnet build command .NET Test / .NET 8.0 (push) Failing after 1m13s Details .NET Test / .NET 9.0 (push) Failing after 1m20s Details	2025-11-11 19:04:29 +04:00
just	034a88ba8f	pipeline fix .NET Test / .NET 9.0 (push) Failing after 42s Details .NET Test / .NET 8.0 (push) Has been cancelled Details	2025-11-11 19:01:52 +04:00
just	e28fc62b31	switch from FluentAssertions to Shouldly .NET Test / test (8.x) (push) Failing after 1m21s Details .NET Test / test (9.x) (push) Failing after 1m25s Details	2025-11-11 17:57:10 +04:00