refactor(patch): initialize DiffHunk with all the information accessible immediately

lib/src/diff.dart

@@ -4,7 +4,6 @@ import 'package:ffi/ffi.dart';
 import 'package:libgit2dart/libgit2dart.dart';
 import 'package:libgit2dart/src/bindings/diff.dart' as bindings;
 import 'package:libgit2dart/src/bindings/libgit2_bindings.dart';
-import 'package:libgit2dart/src/bindings/patch.dart' as patch_bindings;
 import 'package:libgit2dart/src/util.dart';
 
 class Diff {
@@ -602,112 +601,3 @@ final _statsFinalizer = Finalizer<Pointer<git_diff_stats>>(
   (pointer) => bindings.statsFree(pointer),
 );
 // coverage:ignore-end
-
-class DiffHunk {
-  /// Initializes a new instance of [DiffHunk] class from provided
-  /// pointers to patch object and diff hunk object in memory and number of
-  /// lines in hunk.
-  const DiffHunk(
-    this._patchPointer,
-    this._diffHunkPointer,
-    this.linesCount,
-    this.index,
-  );
-
-  /// Pointer to memory address for allocated diff hunk object.
-  final Pointer<git_diff_hunk> _diffHunkPointer;
-
-  /// Pointer to memory address for allocated patch object.
-  final Pointer<git_patch> _patchPointer;
-
-  /// Number of total lines in this hunk.
-  final int linesCount;
-
-  /// Index of this hunk in the patch.
-  final int index;
-
-  /// Starting line number in 'old file'.
-  int get oldStart => _diffHunkPointer.ref.old_start;
-
-  /// Number of lines in 'old file'.
-  int get oldLines => _diffHunkPointer.ref.old_lines;
-
-  /// Starting line number in 'new file'.
-  int get newStart => _diffHunkPointer.ref.new_start;
-
-  /// Number of lines in 'new file'.
-  int get newLines => _diffHunkPointer.ref.new_lines;
-
-  /// Header of a hunk.
-  String get header {
-    final list = <int>[];
-    for (var i = 0; i < _diffHunkPointer.ref.header_len; i++) {
-      list.add(_diffHunkPointer.ref.header[i]);
-    }
-    return String.fromCharCodes(list);
-  }
-
-  /// List of lines in a hunk of a patch.
-  List<DiffLine> get lines {
-    final lines = <DiffLine>[];
-    for (var i = 0; i < linesCount; i++) {
-      lines.add(
-        DiffLine(
-          patch_bindings.lines(
-            patchPointer: _patchPointer,
-            hunkIndex: index,
-            lineOfHunk: i,
-          ),
-        ),
-      );
-    }
-    return lines;
-  }
-
-  @override
-  String toString() {
-    return 'DiffHunk{linesCount: $linesCount, index: $index, '
-        'oldStart: $oldStart, oldLines: $oldLines, newStart: $newStart, '
-        'newLines: $newLines, header: $header}';
-  }
-}
-
-class DiffLine {
-  /// Initializes a new instance of [DiffLine] class from provided
-  /// pointer to diff line object in memory.
-  const DiffLine(this._diffLinePointer);
-
-  /// Pointer to memory address for allocated diff line object.
-  final Pointer<git_diff_line> _diffLinePointer;
-
-  /// Type of the line.
-  GitDiffLine get origin {
-    return GitDiffLine.values.singleWhere(
-      (e) => _diffLinePointer.ref.origin == e.value,
-    );
-  }
-
-  /// Line number in old file or -1 for added line.
-  int get oldLineNumber => _diffLinePointer.ref.old_lineno;
-
-  /// Line number in new file or -1 for deleted line.
-  int get newLineNumber => _diffLinePointer.ref.new_lineno;
-
-  /// Number of newline characters in content.
-  int get numLines => _diffLinePointer.ref.num_lines;
-
-  /// Offset in the original file to the content.
-  int get contentOffset => _diffLinePointer.ref.content_offset;
-
-  /// Content of the diff line.
-  String get content => _diffLinePointer.ref.content
-      .cast<Utf8>()
-      .toDartString(length: _diffLinePointer.ref.content_len);
-
-  @override
-  String toString() {
-    return 'DiffLine{oldLineNumber: $oldLineNumber, '
-        'newLineNumber: $newLineNumber, numLines: $numLines, '
-        'contentOffset: $contentOffset, content: $content}';
-  }
-}

lib/src/patch.dart

@@ -1,5 +1,6 @@
 import 'dart:ffi';
 
+import 'package:ffi/ffi.dart';
 import 'package:libgit2dart/libgit2dart.dart';
 import 'package:libgit2dart/src/bindings/libgit2_bindings.dart';
 import 'package:libgit2dart/src/bindings/patch.dart' as bindings;
@@ -197,14 +198,49 @@ class Patch {
     final length = bindings.numHunks(_patchPointer);
     final hunks = <DiffHunk>[];
 
-    for (var i = 0; i < length; i++) {
-      final hunk = bindings.hunk(patchPointer: _patchPointer, hunkIndex: i);
+    for (var index = 0; index < length; index++) {
+      final hunk = bindings.hunk(patchPointer: _patchPointer, hunkIndex: index);
+      final hunkPointer = hunk['hunk']! as Pointer<git_diff_hunk>;
+      final linesCount = hunk['linesN']! as int;
+
+      final lines = <DiffLine>[];
+      for (var i = 0; i < linesCount; i++) {
+        final linePointer = bindings.lines(
+          patchPointer: _patchPointer,
+          hunkIndex: index,
+          lineOfHunk: i,
+        );
+        lines.add(
+          DiffLine._(
+            origin: GitDiffLine.values.singleWhere(
+              (e) => linePointer.ref.origin == e.value,
+            ),
+            oldLineNumber: linePointer.ref.old_lineno,
+            newLineNumber: linePointer.ref.new_lineno,
+            numLines: linePointer.ref.num_lines,
+            contentOffset: linePointer.ref.content_offset,
+            content: linePointer.ref.content
+                .cast<Utf8>()
+                .toDartString(length: linePointer.ref.content_len),
+          ),
+        );
+      }
+
+      final intHeader = <int>[];
+      for (var i = 0; i < hunkPointer.ref.header_len; i++) {
+        intHeader.add(hunkPointer.ref.header[i]);
+      }
+
       hunks.add(
-        DiffHunk(
-          _patchPointer,
-          hunk['hunk']! as Pointer<git_diff_hunk>,
-          hunk['linesN']! as int,
-          i,
+        DiffHunk._(
+          linesCount: linesCount,
+          index: index,
+          oldStart: hunkPointer.ref.old_start,
+          oldLines: hunkPointer.ref.old_lines,
+          newStart: hunkPointer.ref.new_start,
+          newLines: hunkPointer.ref.new_lines,
+          header: String.fromCharCodes(intHeader),
+          lines: lines,
         ),
       );
     }
@@ -251,3 +287,83 @@ class PatchStats {
         'deletions: $deletions}';
   }
 }
+
+class DiffHunk {
+  const DiffHunk._({
+    required this.linesCount,
+    required this.index,
+    required this.oldStart,
+    required this.oldLines,
+    required this.newStart,
+    required this.newLines,
+    required this.header,
+    required this.lines,
+  });
+
+  /// Number of total lines in this hunk.
+  final int linesCount;
+
+  /// Index of this hunk in the patch.
+  final int index;
+
+  /// Starting line number in 'old file'.
+  final int oldStart;
+
+  /// Number of lines in 'old file'.
+  final int oldLines;
+
+  /// Starting line number in 'new file'.
+  final int newStart;
+
+  /// Number of lines in 'new file'.
+  final int newLines;
+
+  /// Header of a hunk.
+  final String header;
+
+  /// List of lines in a hunk of a patch.
+  final List<DiffLine> lines;
+
+  @override
+  String toString() {
+    return 'DiffHunk{linesCount: $linesCount, index: $index, '
+        'oldStart: $oldStart, oldLines: $oldLines, newStart: $newStart, '
+        'newLines: $newLines, header: $header}';
+  }
+}
+
+class DiffLine {
+  const DiffLine._({
+    required this.origin,
+    required this.oldLineNumber,
+    required this.newLineNumber,
+    required this.numLines,
+    required this.contentOffset,
+    required this.content,
+  });
+
+  /// Type of the line.
+  final GitDiffLine origin;
+
+  /// Line number in old file or -1 for added line.
+  final int oldLineNumber;
+
+  /// Line number in new file or -1 for deleted line.
+  final int newLineNumber;
+
+  /// Number of newline characters in content.
+  final int numLines;
+
+  /// Offset in the original file to the content.
+  final int contentOffset;
+
+  /// Content of the diff line.
+  final String content;
+
+  @override
+  String toString() {
+    return 'DiffLine{oldLineNumber: $oldLineNumber, '
+        'newLineNumber: $newLineNumber, numLines: $numLines, '
+        'contentOffset: $contentOffset, content: $content}';
+  }
+}

test/diff_test.dart

@@ -559,33 +559,6 @@ index e69de29..c217c63 100644
       expect(Diff.parse(patchText).patch, patchText);
     });
 
-    test('returns hunks in a patch', () {
-      final patch = Patch.fromDiff(diff: Diff.parse(patchText), index: 0);
-      final hunk = patch.hunks[0];
-
-      expect(patch.hunks.length, 1);
-      expect(hunk.linesCount, 1);
-      expect(hunk.oldStart, 0);
-      expect(hunk.oldLines, 0);
-      expect(hunk.newStart, 1);
-      expect(hunk.newLines, 1);
-      expect(hunk.header, '@@ -0,0 +1 @@\n');
-    });
-
-    test('returns lines in a hunk', () {
-      final patch = Patch.fromDiff(diff: Diff.parse(patchText), index: 0);
-      final hunk = patch.hunks[0];
-      final line = hunk.lines[0];
-
-      expect(hunk.lines.length, 1);
-      expect(line.origin, GitDiffLine.addition);
-      expect(line.oldLineNumber, -1);
-      expect(line.newLineNumber, 1);
-      expect(line.numLines, 1);
-      expect(line.contentOffset, 155);
-      expect(line.content, 'Modified content\n');
-    });
-
     test('manually releases allocated memory', () {
       final diff = Diff.parse(patchText);
       expect(() => diff.free(), returnsNormally);
@@ -597,8 +570,8 @@ index e69de29..c217c63 100644
     });
 
     test(
-        'returns string representation of Diff, DiffDelta, DiffFile, '
-        'DiffHunk, DiffLine and DiffStats objects', () {
+        'returns string representation of Diff, DiffDelta, DiffFile '
+        ' and DiffStats objects', () {
       final diff = Diff.parse(patchText);
       final patch = Patch.fromDiff(diff: diff, index: 0);
       final stats = diff.stats;
@@ -606,8 +579,6 @@ index e69de29..c217c63 100644
       expect(diff.toString(), contains('Diff{'));
       expect(patch.delta.toString(), contains('DiffDelta{'));
       expect(patch.delta.oldFile.toString(), contains('DiffFile{'));
-      expect(patch.hunks[0].toString(), contains('DiffHunk{'));
-      expect(patch.hunks[0].lines[0].toString(), contains('DiffLine{'));
       expect(stats.toString(), contains('DiffStats{'));
     });
   });

test/patch_test.dart

@@ -155,6 +155,43 @@ index e69de29..0000000
       expect(() => Patch(nullptr).text, throwsA(isA<LibGit2Error>()));
     });
 
+    test('returns hunks in a patch', () {
+      final patch = Patch.fromBuffers(
+        oldBuffer: oldBuffer,
+        newBuffer: newBuffer,
+        oldBufferPath: path,
+        newBufferPath: path,
+      );
+      final hunk = patch.hunks[0];
+
+      expect(patch.hunks.length, 1);
+      expect(hunk.linesCount, 1);
+      expect(hunk.oldStart, 0);
+      expect(hunk.oldLines, 0);
+      expect(hunk.newStart, 1);
+      expect(hunk.newLines, 1);
+      expect(hunk.header, '@@ -0,0 +1 @@\n');
+    });
+
+    test('returns lines in a hunk', () {
+      final patch = Patch.fromBuffers(
+        oldBuffer: oldBuffer,
+        newBuffer: newBuffer,
+        oldBufferPath: path,
+        newBufferPath: path,
+      );
+      final hunk = patch.hunks[0];
+      final line = hunk.lines[0];
+
+      expect(hunk.lines.length, 1);
+      expect(line.origin, GitDiffLine.addition);
+      expect(line.oldLineNumber, -1);
+      expect(line.newLineNumber, 1);
+      expect(line.numLines, 1);
+      expect(line.contentOffset, 0);
+      expect(line.content, 'Feature edit\n');
+    });
+
     test('returns line counts of each type in a patch', () {
       final patch = Patch.fromBuffers(
         oldBuffer: oldBuffer,
@@ -180,7 +217,9 @@ index e69de29..0000000
       expect(() => patch.free(), returnsNormally);
     });
 
-    test('returns string representation of Patch object', () {
+    test(
+        'returns string representation of Patch, DiffHunk and DiffLine objects',
+        () {
       final patch = Patch.fromBuffers(
         oldBuffer: oldBuffer,
         newBuffer: newBuffer,
@@ -189,6 +228,8 @@ index e69de29..0000000
       );
 
       expect(patch.toString(), contains('Patch{'));
+      expect(patch.hunks[0].toString(), contains('DiffHunk{'));
+      expect(patch.hunks[0].lines[0].toString(), contains('DiffLine{'));
     });
   });
 }