Enhance seeder with additional cipher types and architectural refactorings (#6935)

test/SeederApi.IntegrationTest/DistributionTests.cs

@@ -0,0 +1,175 @@
+using Bit.Seeder.Data.Distributions;
+using Xunit;
+
+namespace Bit.SeederApi.IntegrationTest;
+
+public class DistributionTests
+{
+    [Fact]
+    public void Constructor_PercentagesSumToOne_Succeeds()
+    {
+        var distribution = new Distribution<string>(
+            ("A", 0.50),
+            ("B", 0.30),
+            ("C", 0.20)
+        );
+
+        Assert.NotNull(distribution);
+    }
+
+    [Fact]
+    public void Constructor_PercentagesDoNotSumToOne_ThrowsArgumentException()
+    {
+        var exception = Assert.Throws<ArgumentException>(() => new Distribution<int>(
+            (1, 0.50),
+            (2, 0.40)
+        ));
+
+        Assert.Contains("must sum to 1.0", exception.Message);
+    }
+
+    [Fact]
+    public void Constructor_PercentagesExceedOne_ThrowsArgumentException()
+    {
+        var exception = Assert.Throws<ArgumentException>(() => new Distribution<string>(
+            ("X", 0.60),
+            ("Y", 0.60)
+        ));
+
+        Assert.Contains("must sum to 1.0", exception.Message);
+    }
+
+    [Fact]
+    public void Constructor_WithinToleranceOf001_Succeeds()
+    {
+        var distribution = new Distribution<string>(
+            ("A", 0.333),
+            ("B", 0.333),
+            ("C", 0.333)
+        );
+
+        Assert.NotNull(distribution);
+    }
+
+    [Fact]
+    public void Select_ReturnsCorrectBuckets_ForEvenSplit()
+    {
+        var distribution = new Distribution<string>(
+            ("A", 0.50),
+            ("B", 0.50)
+        );
+
+        Assert.Equal("A", distribution.Select(0, 100));
+        Assert.Equal("A", distribution.Select(49, 100));
+        Assert.Equal("B", distribution.Select(50, 100));
+        Assert.Equal("B", distribution.Select(99, 100));
+    }
+
+    [Fact]
+    public void Select_ReturnsCorrectBuckets_ForThreeWaySplit()
+    {
+        var distribution = new Distribution<int>(
+            (1, 0.60),
+            (2, 0.30),
+            (3, 0.10)
+        );
+
+        Assert.Equal(1, distribution.Select(0, 100));
+        Assert.Equal(1, distribution.Select(59, 100));
+        Assert.Equal(2, distribution.Select(60, 100));
+        Assert.Equal(2, distribution.Select(89, 100));
+        Assert.Equal(3, distribution.Select(90, 100));
+        Assert.Equal(3, distribution.Select(99, 100));
+    }
+
+    [Fact]
+    public void Select_IndexBeyondTotal_ReturnsLastBucket()
+    {
+        var distribution = new Distribution<string>(
+            ("A", 0.50),
+            ("B", 0.50)
+        );
+
+        Assert.Equal("B", distribution.Select(150, 100));
+    }
+
+    [Fact]
+    public void Select_SmallTotal_HandlesRoundingGracefully()
+    {
+        var distribution = new Distribution<string>(
+            ("A", 0.33),
+            ("B", 0.33),
+            ("C", 0.34)
+        );
+
+        Assert.Equal("A", distribution.Select(0, 10));
+        Assert.Equal("A", distribution.Select(2, 10));
+        Assert.Equal("B", distribution.Select(3, 10));
+        Assert.Equal("C", distribution.Select(9, 10));
+    }
+
+    [Fact]
+    public void GetCounts_ReturnsCorrectCounts_ForEvenSplit()
+    {
+        var distribution = new Distribution<string>(
+            ("X", 0.50),
+            ("Y", 0.50)
+        );
+
+        var counts = distribution.GetCounts(100).ToList();
+
+        Assert.Equal(2, counts.Count);
+        Assert.Equal(("X", 50), counts[0]);
+        Assert.Equal(("Y", 50), counts[1]);
+    }
+
+    [Fact]
+    public void GetCounts_LastBucketReceivesRemainder()
+    {
+        var distribution = new Distribution<string>(
+            ("A", 0.33),
+            ("B", 0.33),
+            ("C", 0.34)
+        );
+
+        var counts = distribution.GetCounts(100).ToList();
+
+        Assert.Equal(3, counts.Count);
+        Assert.Equal(33, counts[0].Count);
+        Assert.Equal(33, counts[1].Count);
+        Assert.Equal(34, counts[2].Count);
+    }
+
+    [Fact]
+    public void GetCounts_TotalCountsMatchInput()
+    {
+        var distribution = new Distribution<int>(
+            (1, 0.25),
+            (2, 0.25),
+            (3, 0.25),
+            (4, 0.25)
+        );
+
+        var counts = distribution.GetCounts(1000).ToList();
+        var total = counts.Sum(c => c.Count);
+
+        Assert.Equal(1000, total);
+    }
+
+    [Fact]
+    public void Select_IsDeterministic_SameInputSameOutput()
+    {
+        var distribution = new Distribution<string>(
+            ("Alpha", 0.40),
+            ("Beta", 0.35),
+            ("Gamma", 0.25)
+        );
+
+        for (int i = 0; i < 100; i++)
+        {
+            var first = distribution.Select(i, 100);
+            var second = distribution.Select(i, 100);
+            Assert.Equal(first, second);
+        }
+    }
+}