refactor: ReportGenerateServiceをセクション分割し比較ロジックとドキュメント/テストを改善

Author: Widthdom

FolderDiffIL4DotNet.Tests/Services/FolderDiffServiceTests.cs

@@ -140,6 +140,32 @@ public async Task ExecuteFolderDiffAsync_ClearsPreviousRunStateAtStart()
             Assert.Empty(_resultLists.NewFilesAbsolutePath);
         }
 
+        [Fact]
+        public async Task ExecuteFolderDiffAsync_TextExtensionComparison_IsCaseInsensitive()
+        {
+            var oldDir = Path.Combine(_rootDir, "old-case-insensitive");
+            var newDir = Path.Combine(_rootDir, "new-case-insensitive");
+            var reportDir = Path.Combine(_rootDir, "report-case-insensitive");
+            Directory.CreateDirectory(oldDir);
+            Directory.CreateDirectory(newDir);
+            Directory.CreateDirectory(reportDir);
+
+            const string fileRelativePath = "sample.TxT";
+            WriteFile(oldDir, fileRelativePath, "before");
+            WriteFile(newDir, fileRelativePath, "after");
+
+            var config = CreateConfig(maxParallelism: 1);
+            config.TextFileExtensions = new List<string> { ".TXT" };
+            using var progressReporter = new ProgressReportService();
+            var service = new FolderDiffService(config, progressReporter, oldDir, newDir, reportDir, _serviceProvider, _resultLists, _logger);
+
+            await service.ExecuteFolderDiffAsync();
+
+            Assert.Equal(
+                FileDiffResultLists.DiffDetailResult.TextMismatch,
+                _resultLists.FileRelativePathToDiffDetailDictionary[fileRelativePath]);
+        }
+
         private static ConfigSettings CreateConfig(int maxParallelism) => new()
         {
             IgnoredExtensions = new List<string> { ".pdb" },

FolderDiffIL4DotNet.Tests/Services/ReportGenerateServiceTests.cs

@@ -213,6 +213,60 @@ public void GenerateDiffReport_HeaderShowsEmptyIlContainsIgnoreNote_WhenEnabledB
             Assert.Contains("IL line-ignore-by-contains is enabled, but no non-empty strings are configured.", reportText);
         }
 
+        [Fact]
+        public void GenerateDiffReport_WritesAllMainSections()
+        {
+            var oldDir = Path.Combine(_rootDir, "old-sections");
+            var newDir = Path.Combine(_rootDir, "new-sections");
+            var reportDir = Path.Combine(_rootDir, "report-sections");
+            Directory.CreateDirectory(oldDir);
+            Directory.CreateDirectory(newDir);
+            Directory.CreateDirectory(reportDir);
+
+            var oldSame = Path.Combine(oldDir, "same.txt");
+            var newSame = Path.Combine(newDir, "same.txt");
+            var oldModified = Path.Combine(oldDir, "modified.txt");
+            var newModified = Path.Combine(newDir, "modified.txt");
+            var oldRemoved = Path.Combine(oldDir, "removed.txt");
+            var newAdded = Path.Combine(newDir, "added.txt");
+            File.WriteAllText(oldSame, "same");
+            File.WriteAllText(newSame, "same");
+            File.WriteAllText(oldModified, "before");
+            File.WriteAllText(newModified, "after");
+            File.WriteAllText(oldRemoved, "removed");
+            File.WriteAllText(newAdded, "added");
+
+            _resultLists.SetOldFilesAbsolutePath(new List<string> { oldSame, oldModified, oldRemoved });
+            _resultLists.SetNewFilesAbsolutePath(new List<string> { newSame, newModified, newAdded });
+            _resultLists.AddUnchangedFileRelativePath("same.txt");
+            _resultLists.RecordDiffDetail("same.txt", FileDiffResultLists.DiffDetailResult.MD5Match);
+            _resultLists.AddModifiedFileRelativePath("modified.txt");
+            _resultLists.RecordDiffDetail("modified.txt", FileDiffResultLists.DiffDetailResult.TextMismatch);
+            _resultLists.AddRemovedFileAbsolutePath(oldRemoved);
+            _resultLists.AddAddedFileAbsolutePath(newAdded);
+            _resultLists.RecordIgnoredFile("ignored.pdb", FileDiffResultLists.IgnoredFileLocation.Old);
+
+            var config = CreateConfig();
+            config.ShouldIncludeIgnoredFiles = true;
+            _service.GenerateDiffReport(
+                oldDir,
+                newDir,
+                reportDir,
+                appVersion: "test",
+                elapsedTimeString: "00:00:01.000",
+                computerName: "test-host",
+                config);
+
+            var reportPath = Path.Combine(reportDir, "diff_report.md");
+            var reportText = File.ReadAllText(reportPath);
+            Assert.Contains("## [ x ] Ignored Files", reportText);
+            Assert.Contains("## [ = ] Unchanged Files", reportText);
+            Assert.Contains("## [ + ] Added Files", reportText);
+            Assert.Contains("## [ - ] Removed Files", reportText);
+            Assert.Contains("## [ * ] Modified Files", reportText);
+            Assert.Contains("## Summary", reportText);
+        }
+
         [Fact]
         public void GenerateDiffReport_WritesSummaryWarning_WhenMd5MismatchExists()
         {

Program.cs

@@ -303,17 +303,13 @@ static async Task<int> Main(string[] args)
                     stopwatch.Stop();
                     // フォルダ差分比較処理時間のコンソール出力
                     {
-                        TimeSpan? lastRunDuration = stopwatch.Elapsed;
-
-                        if (lastRunDuration.HasValue)
-                        {
-                            string hourString = $"{(int)Math.Floor(lastRunDuration.Value.TotalHours):00}";
-                            string minuteString = $"{lastRunDuration.Value.Minutes:00}";
-                            string secondString = $"{lastRunDuration.Value.Seconds:00}";
-                            string millisecondString = $"{lastRunDuration.Value.Milliseconds:000}";
-                            _elapsedTimeString = $"{hourString}:{minuteString}:{secondString}.{millisecondString}";
-                            _logger.LogMessage(AppLogLevel.Info, string.Format(Constants.LOG_ELAPSED_TIME, _elapsedTimeString), shouldOutputMessageToConsole: true);
-                        }
+                        TimeSpan lastRunDuration = stopwatch.Elapsed;
+                        string hourString = $"{(int)Math.Floor(lastRunDuration.TotalHours):00}";
+                        string minuteString = $"{lastRunDuration.Minutes:00}";
+                        string secondString = $"{lastRunDuration.Seconds:00}";
+                        string millisecondString = $"{lastRunDuration.Milliseconds:000}";
+                        _elapsedTimeString = $"{hourString}:{minuteString}:{secondString}.{millisecondString}";
+                        _logger.LogMessage(AppLogLevel.Info, string.Format(Constants.LOG_ELAPSED_TIME, _elapsedTimeString), shouldOutputMessageToConsole: true);
                     }
                 }
                 #endregion

README.en.md

@@ -101,6 +101,7 @@ Relation to CI:
 - Uses `ILoggerService` (`LoggerService` implementation) via DI; the log file path is exposed through the read-only `LogFileAbsolutePath` property.
 - `Program` builds dependencies with `ServiceCollection` and resolves `ConfigService` / `FolderDiffService` / `ReportGenerateService` instead of directly constructing them with `new`.
 - Writes per-bucket listings to `Reports/<report label>/diff_report.md`; paths are relative for `Unchanged`/`Modified` and absolute for `Added`/`Removed`.
+  - `ReportGenerateService.GenerateDiffReport` is split into private section writers (header/legend/body/summary) to improve readability and maintenance.
 - For `ILMatch` / `ILMismatch`, the report also includes the disassembler tool and version used (including cache hits).
 - Summarizes counts per bucket in the same report.
 - The report header lists only the disassembler labels actually observed during IL comparison (or `N/A` when not used).
@@ -111,7 +112,7 @@ Relation to CI:
 
 1. **MD5 hash** – if hashes match, the file is `Unchanged (MD5Match)`.
 2. **IL diff** – if the file is a .NET assembly (detected via PE/CLR headers, regardless of extension), the app disassembles both versions with the same disassembler/version identity, strips `// MVID:` lines, and compares them line by line. If `ShouldIgnoreILLinesContainingConfiguredStrings` is enabled, lines containing any entry in `ILIgnoreLineContainingStrings` are also ignored (substring match). Matches become `Unchanged (ILMatch)`; mismatches become `Modified (ILMismatch)`.
-3. **Text diff** – if the extension appears in `TextFileExtensions`, a line-based text diff runs. Matches are `Unchanged (TextMatch)`; mismatches are `Modified (TextMismatch)`.
+3. **Text diff** – if the extension appears in `TextFileExtensions` (checked with `StringComparison.OrdinalIgnoreCase`), a line-based text diff runs. Matches are `Unchanged (TextMatch)`; mismatches are `Modified (TextMismatch)`.
 4. **Fallback** – remaining files are treated as `Modified (MD5Mismatch)`.
 
 ## Configuration (`config.json`)
@@ -218,7 +219,7 @@ Place `config.json` next to the executable. Example:
 | Key | Description |
 | --- | --- |
 | `IgnoredExtensions` | Excludes matching extensions from comparison (e.g., `.pdb`). |
-| `TextFileExtensions` | Treats matching extensions as text, diffed line by line. Include the dot (e.g., `.cs`, `.json`). |
+| `TextFileExtensions` | Treats matching extensions as text, diffed line by line. Include the dot (e.g., `.cs`, `.json`). Matching is case-insensitive (`StringComparison.OrdinalIgnoreCase`). |
 | `MaxLogGenerations` | Number of log files kept in rotation. |
 | `ShouldIncludeUnchangedFiles` | Whether to list `Unchanged` files inside `Reports/<label>/diff_report.md`. |
 | `ShouldIncludeIgnoredFiles` | Whether to output ignored files in the `## [ x ] Ignored Files` section (before `Unchanged`). |

README.md

@@ -107,6 +107,7 @@ CI との関係:
 - ログ出力は `ILoggerService`（`LoggerService` 実装）を DI で解決し、ログファイルパスは読み取り専用プロパティ（`LogFileAbsolutePath`）経由で参照
 - `Program` は `ServiceCollection` で依存関係を構成し、`ConfigService` / `FolderDiffService` / `ReportGenerateService` などを直接 `new` せず解決して実行
 - 比較結果区分ごとのファイル一覧を`Reports/<コマンドライン第3引数に指定したレポートのラベル>/diff_report.md`に出力（ファイルのパス、最終更新日時［`config.json`のShouldOutputFileTimestampsが `true` の場合］、判定根拠）
+    - レポート生成は `ReportGenerateService.GenerateDiffReport` からヘッダ/レジェンド/各セクション/サマリーの private メソッドへ分割され、保守性を高めています。
     - Unchanged/Modified は相対パスで記載されます。
     - Added/Removed は絶対パスで記載されます。
     - `ILMatch` / `ILMismatch` には、逆アセンブルに使用したツール名/バージョンを併記します（キャッシュ利用時を含む）。
@@ -131,7 +132,7 @@ CI との関係:
 	- 逆アセンブルに`dotnet-ildasm`を使用した場合、IL 先頭付近に「// MVID: {GUID}」が出力されることが多い一方、`ilspycmd`を使用した場合は出力されません。
 - 一致ならばUnchanged, ILMatch、不一致ならばModified, ILMismatchと判定し次のファイル比較へ
 
-3) テキストベースのファイル（`config.json`のTextFileExtensionsに指定された拡張子か否かで判定）であれば行単位で比較します。
+3) テキストベースのファイル（`config.json`のTextFileExtensionsに指定された拡張子か否かを `StringComparison.OrdinalIgnoreCase` で判定）であれば行単位で比較します。
 - 一致ならばUnchanged, TextMatch、不一致ならばModified, TextMismatchと判定し次のファイル比較へ
 
 4) Modified, MD5Mismatchと判定し次のファイル比較へ
@@ -240,7 +241,7 @@ CI との関係:
 | 項目 | 説明 |
 | --- | --- |
 | IgnoredExtensions | 指定拡張子は比較対象から除外する（例: `.pdb`）。 |
-| TextFileExtensions | 指定拡張子のファイルはテキストとして行単位で比較する。ピリオド（`.`）付きで指定すること（例: `.cs`, `.json`, `.xml`）。 |
+| TextFileExtensions | 指定拡張子のファイルはテキストとして行単位で比較する。ピリオド（`.`）付きで指定すること（例: `.cs`, `.json`, `.xml`）。比較は大文字小文字を区別せず（`StringComparison.OrdinalIgnoreCase`）行われる。 |
 | MaxLogGenerations | アプリケーションログのローテーション世代数。 |
 | ShouldIncludeUnchangedFiles | `Reports/<コマンドライン第3引数に指定したレポートのラベル>/diff_report.md`にUnchangedのファイル一覧を含めるか否か。 |
 | ShouldIncludeIgnoredFiles | IgnoredExtensions に該当して比較対象から除外されたファイルを `diff_report.md` の `## [ x ] Ignored Files` セクション（Unchanged の直前）に出力するか否か。 |

Services/FileDiffService.cs

@@ -148,7 +148,8 @@ public async Task<bool> FilesAreEqualAsync(string fileRelativePath, int maxParal
                 }
 
                 // 3) テキスト拡張子ならテキスト比較: ネットワーク最適化時は逐次、それ以外は閾値に応じて並列比較を選択。
-                if (_config.TextFileExtensions.Contains(Path.GetExtension(file1AbsolutePath).ToLower()))
+                string fileExtension = Path.GetExtension(file1AbsolutePath);
+                if (_config.TextFileExtensions.Any(configuredExtension => string.Equals(configuredExtension, fileExtension, StringComparison.OrdinalIgnoreCase)))
                 {
                     int textDiffParallelThresholdBytes = GetEffectiveBytesFromConfiguredKilobytes(
                         configuredKilobytes: _config.TextDiffParallelThresholdKilobytes,