Implement normalizer PoC (#4)

tests/Recordingtest.Normalizer.Tests/RuleTests.cs

@@ -0,0 +1,78 @@
+using System.Text.Json.Nodes;
+using Xunit;
+using Recordingtest.Normalizer;
+
+namespace Recordingtest.Normalizer.Tests;
+
+public class RuleTests
+{
+    [Fact]
+    public void StripTimestamps_ReplacesIso8601()
+    {
+        var input = "saved at 2026-04-07T12:34:56.789Z and 2025-01-02 03:04:05";
+        var (o, c) = Rules.StripTimestamps(input);
+        Assert.Equal(2, c);
+        Assert.Equal("saved at <TS> and <TS>", o);
+    }
+
+    [Fact]
+    public void MaskGuids_ReplacesUuids()
+    {
+        var input = "id=550e8400-e29b-41d4-a716-446655440000 done";
+        var (o, c) = Rules.MaskGuids(input);
+        Assert.Equal(1, c);
+        Assert.Contains("<GUID>", o);
+    }
+
+    [Fact]
+    public void NormalizePaths_ReplacesRepoAndUser()
+    {
+        Environment.SetEnvironmentVariable("RECORDINGTEST_REPO", @"D:\proj\recordingtest");
+        var input = @"file: D:\proj\recordingtest\foo\bar.txt";
+        var (o, c) = Rules.NormalizePaths(input);
+        Assert.True(c >= 1);
+        Assert.Contains("<REPO>", o);
+        Environment.SetEnvironmentVariable("RECORDINGTEST_REPO", null);
+    }
+
+    [Fact]
+    public void RoundFloats_RoundsToSixDecimals()
+    {
+        var node = JsonNode.Parse("{\"x\": 3.1415926535897932, \"n\": 1}");
+        var (n, c) = Rules.RoundFloatsInNode(node);
+        Assert.Equal(1, c);
+        Assert.Equal(3.141593, n!["x"]!.GetValue<double>());
+    }
+
+    [Fact]
+    public void SortJsonKeys_RecursivelySortsObjects()
+    {
+        var node = JsonNode.Parse("{\"b\":1,\"a\":{\"y\":2,\"x\":1}}");
+        var (sorted, _) = Rules.SortJsonKeys(node);
+        var s = sorted!.ToJsonString();
+        Assert.Equal("{\"a\":{\"x\":1,\"y\":2},\"b\":1}", s);
+    }
+
+    [Fact]
+    public void Normalize_IsIdempotent()
+    {
+        var input = "{\"b\":2.0000001,\"a\":\"2026-04-07T00:00:00Z\",\"id\":\"550e8400-e29b-41d4-a716-446655440000\"}";
+        var first = Normalizer.Normalize(input, "default");
+        var second = Normalizer.Normalize(first.Output, "default");
+        Assert.Equal(first.Output, second.Output);
+    }
+
+    [Fact]
+    public void Normalize_AppliesAllDefaultRules()
+    {
+        var input = "{\"ts\":\"2026-04-07T00:00:00Z\",\"x\":1.23456789}";
+        var r = Normalizer.Normalize(input, "default");
+        Assert.Equal(5, r.Log.Count);
+        var ids = r.Log.Select(l => l.RuleId).ToList();
+        Assert.Contains("strip_timestamps", ids);
+        Assert.Contains("mask_guids", ids);
+        Assert.Contains("normalize_paths", ids);
+        Assert.Contains("round_floats", ids);
+        Assert.Contains("sort_json_keys", ids);
+    }
+}