Add regression tests for trimming and hash table reordering

Author: Genbox

Src/FastData.Tests/FastDataGeneratorTests.cs

@@ -1,4 +1,7 @@
 using Genbox.FastData.Enums;
+using Genbox.FastData.Generators;
+using Genbox.FastData.Generators.Abstracts;
+using Genbox.FastData.Generators.Contexts;
 using Genbox.FastData.InternalShared;
 using Genbox.FastData.InternalShared.TestClasses;
 
@@ -19,6 +22,54 @@ public void Generate_ThrowOnInvalidType()
         Assert.Throws<InvalidOperationException>(() => FastDataGenerator.Generate([DateTime.Now, DateTime.UtcNow], new FastDataConfig(StructureType.Array), new DummyGenerator()));
     }
 
+    [Fact]
+    public void GenerateKeyed_HashTablePerfect_ReordersValuesToMatchSlots()
+    {
+        int[] keys = [2, 0, 1];
+        string[] values = ["v2", "v0", "v1"];
+        FastDataConfig config = new FastDataConfig(StructureType.HashTable) { HashCapacityFactor = 1 };
+        ContextCaptureGenerator generator = new ContextCaptureGenerator();
+
+        FastDataGenerator.GenerateKeyed(keys, values, config, generator);
+
+        HashTablePerfectContext<int, string> ctx = Assert.IsType<HashTablePerfectContext<int, string>>(generator.Context);
+        Assert.NotNull(ctx.Values);
+
+        for (int i = 0; i < ctx.Data.Length; i++)
+        {
+            KeyValuePair<int, ulong> entry = ctx.Data[i];
+            string value = ctx.Values![i];
+            Assert.Equal($"v{entry.Key}", value);
+        }
+    }
+
+    [Fact]
+    public void GenerateKeyed_HashTablePerfect_StoresHashCodeWhenCapacityFactorIsHigh()
+    {
+        int[] keys = [0, 1, 2];
+        string[] values = ["v0", "v1", "v2"];
+        FastDataConfig config = new FastDataConfig(StructureType.HashTable) { HashCapacityFactor = 2 };
+        ContextCaptureGenerator generator = new ContextCaptureGenerator();
+
+        FastDataGenerator.GenerateKeyed(keys, values, config, generator);
+
+        HashTablePerfectContext<int, string> ctx = Assert.IsType<HashTablePerfectContext<int, string>>(generator.Context);
+        Assert.True(ctx.StoreHashCode);
+    }
+
+    [Fact]
+    public void Generate_Trimming_UsesSuffixFromEnd()
+    {
+        string[] keys = ["prefooSUF", "prebarSUF"];
+        FastDataConfig config = new FastDataConfig(StructureType.Array) { EnableTrimming = true };
+        TrimCaptureGenerator generator = new TrimCaptureGenerator();
+
+        FastDataGenerator.Generate(keys, config, generator);
+
+        Assert.Equal("pre", generator.TrimPrefix);
+        Assert.Equal("SUF", generator.TrimSuffix);
+    }
+
     // [Fact]
     // public async Task Generate_SpanSupport()
     // {
@@ -56,4 +107,32 @@ public static TheoryData<ITestData> GetTestData()
         }
         return data;
     }
+
+    private sealed class ContextCaptureGenerator : ICodeGenerator
+    {
+        public GeneratorEncoding Encoding => GeneratorEncoding.UTF8;
+
+        public object? Context { get; private set; }
+
+        public string Generate<TKey, TValue>(GeneratorConfig<TKey> genCfg, IContext<TValue> context)
+        {
+            Context = context;
+            return string.Empty;
+        }
+    }
+
+    private sealed class TrimCaptureGenerator : ICodeGenerator
+    {
+        public GeneratorEncoding Encoding => GeneratorEncoding.UTF8;
+
+        public string TrimPrefix { get; private set; } = string.Empty;
+        public string TrimSuffix { get; private set; } = string.Empty;
+
+        public string Generate<TKey, TValue>(GeneratorConfig<TKey> genCfg, IContext<TValue> context)
+        {
+            TrimPrefix = genCfg.TrimPrefix;
+            TrimSuffix = genCfg.TrimSuffix;
+            return string.Empty;
+        }
+    }
 }