Add assembly semantic changes detection for ILMismatch assemblies

CHANGELOG.md

@@ -9,6 +9,19 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 
 ### [Unreleased]
 
+#### Added
+
+- Added **Assembly Semantic Changes** — member-level change detection for `ILMismatch` assemblies using `System.Reflection.Metadata`. For each modified .NET assembly, the report now shows type/method/property/field additions, removals, and method body changes. Controlled by the new `ShouldIncludeAssemblySemanticChangesInReport` config setting (default: `true`).
+  - **Report placement**: appears between **Summary** and **IL Cache Stats** in the Markdown report; shown as an expandable inline row above the IL diff in the HTML report.
+  - **Table columns** (12 in HTML including checkbox; 11 in Markdown): `✓` (checkbox, HTML only), `Class` (fully qualified type name), `BaseType` (base class + interfaces), `Change` (`Added`/`Removed`/`Modified`), `Kind` (`Class`/`Record`/`Struct`/`Interface`/`Enum`/`Constructor`/`StaticConstructor`/`Method`/`Property`/`Field`), `Access` (`public`/`internal`/`protected`/`private`), `Modifiers` (`static`/`abstract`/`virtual`/`override`/`sealed`/`readonly`/`const`/`static literal`/`static readonly`), `Type` (declared type for Field/Property only), `Name`, `ReturnType`, `Parameters` (displayed without parentheses), `Body` (`Changed` when method body or field initializer IL has changed; otherwise empty).
+  - **Summary count table**: a second table grouped by Class showing `Added`/`Removed`/`Modified` counts. Consecutive rows for the same class merge the Class cell.
+  - **Record detection**: records are identified heuristically by the presence of an `EqualityContract` property.
+  - **HTML styling**: table header background `#98989d` (light grey), data cell (`td`) background `#fff` (white) for contrast against the `diff-row` grey, per-row checkbox with auto-save, resizable columns via CSS custom properties and drag handles.
+  - **Markdown styling**: multi-word Modifiers (e.g. `static literal`) use non-breaking spaces to prevent wrapping.
+  - **New files**: [`AssemblyMethodAnalyzer`](Services/AssemblyMethodAnalyzer.cs), [`AssemblySemanticChangesSummary`](Models/AssemblySemanticChangesSummary.cs) (with computed `AddedCount`/`RemovedCount`/`ModifiedCount` properties).
+  - **Tests**: [`AssemblyMethodAnalyzerTests`](FolderDiffIL4DotNet.Tests/Services/AssemblyMethodAnalyzerTests.cs), [`AssemblySemanticChangesSummaryTests`](FolderDiffIL4DotNet.Tests/Models/AssemblySemanticChangesSummaryTests.cs), and new assertions in [`HtmlReportGenerateServiceTests`](FolderDiffIL4DotNet.Tests/Services/HtmlReportGenerateServiceTests.cs) (`TableHeaderUsesLighterGray`, `ThScColCbCssRuleExists`, `TdHasWhiteBackground`).
+  - **Docs**: added bilingual **Assembly Semantic Changes** section to [README.md](README.md), [`AssemblyMethodAnalyzerTests`](FolderDiffIL4DotNet.Tests/Services/AssemblyMethodAnalyzerTests.cs) and [`AssemblySemanticChangesSummaryTests`](FolderDiffIL4DotNet.Tests/Models/AssemblySemanticChangesSummaryTests.cs) to [TESTING_GUIDE.md](doc/TESTING_GUIDE.md), updated [`doc/samples/diff_report.html`](doc/samples/diff_report.html) and [`doc/samples/diff_report.md`](doc/samples/diff_report.md).
+
 ### [1.4.1] - 2026-03-20
 
 #### Added
@@ -365,6 +378,19 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 
 ### [Unreleased]
 
+#### 追加
+
+- **Assembly Semantic Changes** を追加 — `System.Reflection.Metadata` を使用した `ILMismatch` アセンブリのメンバーレベル変更検出。変更のあった各 .NET アセンブリについて、型・メソッド・プロパティ・フィールドの増減およびメソッドボディの変更をレポートに出力します。新しい設定項目 `ShouldIncludeAssemblySemanticChangesInReport`（既定: `true`）で制御可能。
+  - **レポート配置**: Markdown レポートでは **Summary** と **IL Cache Stats** の間に表示。HTML レポートでは IL diff の上に展開可能なインライン行として表示。
+  - **テーブル列**（HTML: チェックボックス含む 12 列、Markdown: 11 列）: `✓`（チェックボックス、HTML のみ）、`Class`（完全修飾型名）、`BaseType`（基底クラス＋インターフェース）、`Change`（`Added`/`Removed`/`Modified`）、`Kind`（`Class`/`Record`/`Struct`/`Interface`/`Enum`/`Constructor`/`StaticConstructor`/`Method`/`Property`/`Field`）、`Access`（`public`/`internal`/`protected`/`private`）、`Modifiers`（`static`/`abstract`/`virtual`/`override`/`sealed`/`readonly`/`const`/`static literal`/`static readonly`）、`Type`（Field/Property の宣言型のみ）、`Name`、`ReturnType`、`Parameters`（括弧なしで表示）、`Body`（メソッドボディまたはフィールド初期化子の IL 変更時に `Changed`、それ以外は空欄）。
+  - **集計テーブル**: Class 別に `Added`/`Removed`/`Modified` の件数を表示する第二テーブル。同一クラスの連続行は Class セルを結合。
+  - **Record 検出**: `EqualityContract` プロパティの有無で Record 型をヒューリスティックに判定。
+  - **HTML スタイル**: テーブルヘッダ背景 `#98989d`（ライトグレー）、データセル（`td`）背景 `#fff`（白）で `diff-row` グレーとのコントラストを確保、行単位チェックボックス（auto-save 対応）、CSS カスタムプロパティとドラッグハンドルによるリサイズ可能な列。
+  - **Markdown スタイル**: 複数語の Modifiers（例: `static literal`）にノーブレークスペースを適用し折り返しを防止。
+  - **新規ファイル**: [`AssemblyMethodAnalyzer`](Services/AssemblyMethodAnalyzer.cs)、[`AssemblySemanticChangesSummary`](Models/AssemblySemanticChangesSummary.cs)（算出プロパティ `AddedCount`/`RemovedCount`/`ModifiedCount`）。
+  - **テスト**: [`AssemblyMethodAnalyzerTests`](FolderDiffIL4DotNet.Tests/Services/AssemblyMethodAnalyzerTests.cs)、[`AssemblySemanticChangesSummaryTests`](FolderDiffIL4DotNet.Tests/Models/AssemblySemanticChangesSummaryTests.cs)、[`HtmlReportGenerateServiceTests`](FolderDiffIL4DotNet.Tests/Services/HtmlReportGenerateServiceTests.cs) に新規アサーション（`TableHeaderUsesLighterGray`、`ThScColCbCssRuleExists`、`TdHasWhiteBackground`）。
+  - **ドキュメント**: [README.md](README.md) にバイリンガルの **Assembly Semantic Changes** セクションを追加、[TESTING_GUIDE.md](doc/TESTING_GUIDE.md) に [`AssemblyMethodAnalyzerTests`](FolderDiffIL4DotNet.Tests/Services/AssemblyMethodAnalyzerTests.cs)・[`AssemblySemanticChangesSummaryTests`](FolderDiffIL4DotNet.Tests/Models/AssemblySemanticChangesSummaryTests.cs) を追加、[`doc/samples/diff_report.html`](doc/samples/diff_report.html)・[`doc/samples/diff_report.md`](doc/samples/diff_report.md) を同期。
+
 ### [1.4.1] - 2026-03-20
 
 #### 追加

FolderDiffIL4DotNet.Tests/Models/AssemblySemanticChangesSummaryTests.cs

@@ -0,0 +1,56 @@
+using System.Collections.Generic;
+using FolderDiffIL4DotNet.Models;
+using Xunit;
+
+namespace FolderDiffIL4DotNet.Tests.Models
+{
+    public sealed class AssemblySemanticChangesSummaryTests
+    {
+        [Fact]
+        public void HasChanges_DefaultInstance_ReturnsFalse()
+        {
+            var summary = new AssemblySemanticChangesSummary();
+            Assert.False(summary.HasChanges);
+        }
+
+        [Fact]
+        public void HasChanges_WithEntries_ReturnsTrue()
+        {
+            var summary = new AssemblySemanticChangesSummary
+            {
+                Entries = new List<MemberChangeEntry>
+                {
+                    new("Added", "MyApp.Service", "", "public", "", "Method", "DoWork", "", "void", "int count", ""),
+                },
+            };
+            Assert.True(summary.HasChanges);
+        }
+
+        [Fact]
+        public void HasChanges_EmptyEntries_ReturnsFalse()
+        {
+            var summary = new AssemblySemanticChangesSummary
+            {
+                Entries = new List<MemberChangeEntry>(),
+            };
+            Assert.False(summary.HasChanges);
+        }
+
+        [Fact]
+        public void Entries_ContainStructuredData()
+        {
+            var entry = new MemberChangeEntry("Added", "MyApp.Service", "SomeBase", "public", "static", "Method", "GetName", "", "string", "string id", "");
+            Assert.Equal("Added", entry.Change);
+            Assert.Equal("MyApp.Service", entry.TypeName);
+            Assert.Equal("SomeBase", entry.BaseType);
+            Assert.Equal("public", entry.Access);
+            Assert.Equal("static", entry.Modifiers);
+            Assert.Equal("Method", entry.MemberKind);
+            Assert.Equal("GetName", entry.MemberName);
+            Assert.Equal("", entry.MemberType);
+            Assert.Equal("string", entry.ReturnType);
+            Assert.Equal("string id", entry.Parameters);
+            Assert.Equal("", entry.Body);
+        }
+    }
+}

FolderDiffIL4DotNet.Tests/Services/AssemblyMethodAnalyzerTests.cs

@@ -0,0 +1,79 @@
+using System.Linq;
+using FolderDiffIL4DotNet.Services;
+using Xunit;
+
+namespace FolderDiffIL4DotNet.Tests.Services
+{
+    public sealed class AssemblyMethodAnalyzerTests
+    {
+        [Fact]
+        public void Analyze_SameAssembly_NoChanges()
+        {
+            // Compare a real assembly to itself — should report no changes
+            // 実アセンブリを自分自身と比較 — 変更なしが期待される
+            var assemblyPath = typeof(AssemblyMethodAnalyzerTests).Assembly.Location;
+            var result = AssemblyMethodAnalyzer.Analyze(assemblyPath, assemblyPath);
+
+            Assert.NotNull(result);
+            Assert.False(result.HasChanges);
+            Assert.Empty(result.Entries);
+            Assert.Equal(0, result.AddedCount);
+            Assert.Equal(0, result.RemovedCount);
+            Assert.Equal(0, result.ModifiedCount);
+        }
+
+        [Fact]
+        public void Analyze_NonExistentFile_ReturnsNull()
+        {
+            // Attempting to analyse a missing file should gracefully return null
+            // 存在しないファイルの解析は null を返すべき
+            var result = AssemblyMethodAnalyzer.Analyze("/nonexistent/old.dll", "/nonexistent/new.dll");
+            Assert.Null(result);
+        }
+
+        [Fact]
+        public void Analyze_InvalidFile_ReturnsNull()
+        {
+            // Attempting to analyse a non-PE file should gracefully return null
+            // PE でないファイルの解析は null を返すべき
+            var textFile = typeof(AssemblyMethodAnalyzerTests).Assembly.Location + ".runtimeconfig.json";
+            if (!System.IO.File.Exists(textFile)) return; // skip if runtime config not available
+            var result = AssemblyMethodAnalyzer.Analyze(textFile, textFile);
+            Assert.Null(result);
+        }
+
+        [Fact]
+        public void Analyze_DifferentAssemblies_DetectsChanges()
+        {
+            // Compare test assembly to main assembly — should detect differences
+            // テストアセンブリとメインアセンブリを比較 — 差異が検出されるべき
+            var testAssembly = typeof(AssemblyMethodAnalyzerTests).Assembly.Location;
+            var mainAssembly = typeof(FolderDiffIL4DotNet.Models.ConfigSettings).Assembly.Location;
+
+            var result = AssemblyMethodAnalyzer.Analyze(testAssembly, mainAssembly);
+
+            Assert.NotNull(result);
+            Assert.True(result.HasChanges);
+            Assert.True(result.Entries.Count > 0);
+        }
+
+        [Fact]
+        public void Analyze_DifferentAssemblies_EntriesHaveStructuredData()
+        {
+            // Entries should contain structured MemberChangeEntry data
+            // エントリには構造化された MemberChangeEntry データが含まれるべき
+            var testAssembly = typeof(AssemblyMethodAnalyzerTests).Assembly.Location;
+            var mainAssembly = typeof(FolderDiffIL4DotNet.Models.ConfigSettings).Assembly.Location;
+
+            var result = AssemblyMethodAnalyzer.Analyze(testAssembly, mainAssembly);
+
+            Assert.NotNull(result);
+            var firstEntry = result.Entries.First();
+            Assert.False(string.IsNullOrEmpty(firstEntry.Change));
+            Assert.False(string.IsNullOrEmpty(firstEntry.TypeName));
+            Assert.False(string.IsNullOrEmpty(firstEntry.MemberKind));
+            Assert.Contains(firstEntry.Change, new[] { "Added", "Removed", "Modified" });
+            Assert.Contains(firstEntry.MemberKind, new[] { "Class", "Record", "Struct", "Interface", "Enum", "Constructor", "StaticConstructor", "Method", "Property", "Field" });
+        }
+    }
+}