feat(diff): add bindings and api

test/diff_test.dart

@@ -0,0 +1,271 @@
+import 'dart:io';
+import 'package:libgit2dart/src/git_types.dart';
+import 'package:test/test.dart';
+import 'package:libgit2dart/libgit2dart.dart';
+import 'helpers/util.dart';
+
+void main() {
+  late Repository repo;
+  final tmpDir = '${Directory.systemTemp.path}/diff_testrepo/';
+  const indexToWorkdir = [
+    'file_deleted',
+    'modified_file',
+    'staged_changes_file_deleted',
+    'staged_changes_file_modified',
+    'staged_new_file_deleted',
+    'staged_new_file_modified',
+    'subdir/deleted_file',
+    'subdir/modified_file',
+  ];
+
+  const indexToTree = [
+    'staged_changes',
+    'staged_changes_file_deleted',
+    'staged_changes_file_modified',
+    'staged_delete',
+    'staged_delete_file_modified',
+    'staged_new',
+    'staged_new_file_deleted',
+    'staged_new_file_modified',
+  ];
+
+  const treeToWorkdir = [
+    'file_deleted',
+    'modified_file',
+    'staged_changes',
+    'staged_changes_file_deleted',
+    'staged_changes_file_modified',
+    'staged_delete',
+    'staged_delete_file_modified',
+    'subdir/deleted_file',
+    'subdir/modified_file',
+  ];
+
+  const treeToTree = [
+    'deleted_file',
+    'file_deleted',
+    'staged_changes',
+    'staged_changes_file_deleted',
+    'staged_changes_file_modified',
+    'staged_delete',
+    'staged_delete_file_modified',
+    'subdir/current_file',
+    'subdir/deleted_file',
+    'subdir/modified_file',
+  ];
+
+  const patch = """
+diff --git a/subdir/modified_file b/subdir/modified_file
+index e69de29..c217c63 100644
+--- a/subdir/modified_file
++++ b/subdir/modified_file
+@@ -0,0 +1 @@
++Modified content
+""";
+
+  const statsPrint = """
+ file_deleted                 | 0
+ modified_file                | 1 +
+ staged_changes_file_deleted  | 1 -
+ staged_changes_file_modified | 2 +-
+ staged_new_file_deleted      | 0
+ staged_new_file_modified     | 1 +
+ subdir/deleted_file          | 0
+ subdir/modified_file         | 1 +
+ 8 files changed, 4 insertions(+), 2 deletions(-)
+""";
+
+  setUp(() async {
+    if (await Directory(tmpDir).exists()) {
+      await Directory(tmpDir).delete(recursive: true);
+    }
+    await copyRepo(
+      from: Directory('test/assets/dirtyrepo/'),
+      to: await Directory(tmpDir).create(),
+    );
+    repo = Repository.open(tmpDir);
+  });
+
+  tearDown(() async {
+    repo.free();
+    await Directory(tmpDir).delete(recursive: true);
+  });
+
+  group('Diff', () {
+    test('successfully returns diff between index and workdir', () {
+      final index = repo.index;
+      final diff = index.diffToWorkdir();
+
+      expect(diff.length, 8);
+      for (var i = 0; i < diff.deltas.length; i++) {
+        expect(diff.deltas[i].newFile.path, indexToWorkdir[i]);
+      }
+
+      diff.free();
+      index.free();
+    });
+
+    test('successfully returns diff between index and tree', () {
+      final index = repo.index;
+      final tree = (repo[repo.head.target.sha] as Commit).tree;
+      final diff = index.diffToTree(tree: tree);
+
+      expect(diff.length, 8);
+      for (var i = 0; i < diff.deltas.length; i++) {
+        expect(diff.deltas[i].newFile.path, indexToTree[i]);
+      }
+
+      tree.free();
+      diff.free();
+      index.free();
+    });
+
+    test('successfully returns diff between tree and workdir', () {
+      final tree = (repo[repo.head.target.sha] as Commit).tree;
+      final diff = tree.diffToWorkdir();
+
+      expect(diff.length, 9);
+      for (var i = 0; i < diff.deltas.length; i++) {
+        expect(diff.deltas[i].newFile.path, treeToWorkdir[i]);
+      }
+
+      tree.free();
+      diff.free();
+    });
+
+    test('successfully returns diff between tree and index', () {
+      final index = repo.index;
+      final tree = (repo[repo.head.target.sha] as Commit).tree;
+      final diff = tree.diffToIndex(index: index);
+
+      expect(diff.length, 8);
+      for (var i = 0; i < diff.deltas.length; i++) {
+        expect(diff.deltas[i].newFile.path, indexToTree[i]);
+      }
+
+      tree.free();
+      diff.free();
+      index.free();
+    });
+
+    test('successfully returns diff between tree and tree', () {
+      final tree1 = (repo[repo.head.target.sha] as Commit).tree;
+      final tree2 = repo['b85d53c9236e89aff2b62558adaa885fd1d6ff1c'] as Tree;
+      final diff = tree1.diffToTree(tree: tree2);
+
+      expect(diff.length, 10);
+      for (var i = 0; i < diff.deltas.length; i++) {
+        expect(diff.deltas[i].newFile.path, treeToTree[i]);
+      }
+
+      tree1.free();
+      tree2.free();
+      diff.free();
+    });
+
+    test('successfully merges diffs', () {
+      final tree1 = (repo[repo.head.target.sha] as Commit).tree;
+      final tree2 = repo['b85d53c9236e89aff2b62558adaa885fd1d6ff1c'] as Tree;
+      final diff1 = tree1.diffToTree(tree: tree2);
+      final diff2 = tree1.diffToWorkdir();
+
+      expect(diff1.length, 10);
+      expect(diff2.length, 9);
+
+      diff1.merge(diff2);
+      expect(diff1.length, 11);
+
+      tree1.free();
+      tree2.free();
+      diff1.free();
+      diff2.free();
+    });
+
+    test('successfully parses provided diff', () {
+      final diff = Diff.parse(patch);
+      final stats = diff.stats;
+
+      expect(diff.length, 1);
+      expect(stats.filesChanged, 1);
+      expect(stats.insertions, 1);
+
+      stats.free();
+      diff.free();
+    });
+
+    test('successfully finds similar entries', () {
+      final index = repo.index;
+      final oldTree = (repo[repo.head.target.sha] as Commit).tree;
+      final newTree = repo[index.writeTree().sha] as Tree;
+
+      final diff = oldTree.diffToTree(tree: newTree);
+      expect(
+        diff.deltas.singleWhere((e) => e.newFile.path == 'staged_new').status,
+        GitDelta.added,
+      );
+
+      diff.findSimilar();
+      expect(
+        diff.deltas.singleWhere((e) => e.newFile.path == 'staged_new').status,
+        GitDelta.renamed,
+      );
+
+      diff.free();
+      index.free();
+      oldTree.free();
+      newTree.free();
+    });
+
+    test('returns deltas and patches', () {
+      final index = repo.index;
+      final diff = index.diffToWorkdir();
+
+      expect(diff.deltas[0].numberOfFiles, 1);
+      expect(diff.deltas[0].status, GitDelta.deleted);
+      expect(diff.deltas[0].statusChar, 'D');
+      expect(diff.deltas[0].flags, isEmpty);
+      expect(diff.deltas[0].similarity, 0);
+
+      expect(diff.deltas[0].oldFile.path, indexToWorkdir[0]);
+      expect(
+        diff.deltas[0].oldFile.id.sha,
+        'e69de29bb2d1d6434b8b29ae775ad8c2e48c5391',
+      );
+      expect(
+        diff.deltas[0].newFile.id.sha,
+        '0000000000000000000000000000000000000000',
+      );
+
+      expect(diff.deltas[2].oldFile.size, 17);
+
+      expect(
+        diff.deltas[0].oldFile.flags,
+        {GitDiffFlag.validId, GitDiffFlag.exists},
+      );
+      expect(
+        diff.deltas[0].newFile.flags,
+        {GitDiffFlag.validId},
+      );
+
+      expect(diff.deltas[0].oldFile.mode, GitFilemode.blob);
+
+      diff.free();
+      index.free();
+    });
+
+    test('returns stats', () {
+      final index = repo.index;
+      final diff = index.diffToWorkdir();
+      final stats = diff.stats;
+
+      expect(stats.insertions, 4);
+      expect(stats.deletions, 2);
+      expect(stats.filesChanged, 8);
+      expect(stats.print({GitDiffStats.full}, 80), statsPrint);
+
+      stats.free();
+      diff.free();
+      index.free();
+    });
+  });
+}