feat(blob): add bindings and api

test/blob_test.dart

@@ -0,0 +1,100 @@
+import 'dart:io';
+
+import 'package:test/test.dart';
+import 'package:libgit2dart/libgit2dart.dart';
+import 'helpers/util.dart';
+
+void main() {
+  late Repository repo;
+  late Blob blob;
+  final tmpDir = '${Directory.systemTemp.path}/blob_testrepo/';
+  const blobSHA = '9c78c21d6680a7ffebc76f7ac68cacc11d8f48bc';
+  const blobContent = 'Feature edit\n';
+  const newBlobContent = 'New blob\n';
+
+  setUp(() async {
+    if (await Directory(tmpDir).exists()) {
+      await Directory(tmpDir).delete(recursive: true);
+    }
+    await copyRepo(
+      from: Directory('test/assets/testrepo/'),
+      to: await Directory(tmpDir).create(),
+    );
+    repo = Repository.open(tmpDir);
+    blob = Blob.lookup(repo, Oid.fromSHA(repo, blobSHA));
+  });
+
+  tearDown(() async {
+    blob.free();
+    repo.free();
+    await Directory(tmpDir).delete(recursive: true);
+  });
+
+  group('Blob', () {
+    test('successfully initializes blob from provided Oid', () {
+      expect(blob, isA<Blob>());
+    });
+
+    test('returns correct values', () {
+      expect(blob.id.sha, blobSHA);
+      expect(blob.isBinary, false);
+      expect(blob.size, 13);
+      expect(blob.content, blobContent);
+    });
+
+    test('successfully creates new blob', () {
+      final oid = Blob.create(repo, newBlobContent);
+      final newBlob = Blob.lookup(repo, oid);
+
+      expect(newBlob.id.sha, '18fdaeef018e57a92bcad2d4a35b577f34089af6');
+      expect(newBlob.isBinary, false);
+      expect(newBlob.size, 9);
+      expect(newBlob.content, newBlobContent);
+
+      newBlob.free();
+    });
+
+    test('successfully creates new blob from file at provided relative path',
+        () {
+      final oid = Blob.createFromWorkdir(repo, 'feature_file');
+      final newBlob = Blob.lookup(repo, oid);
+
+      expect(newBlob.id.sha, blobSHA);
+      expect(newBlob.isBinary, false);
+      expect(newBlob.size, 13);
+      expect(newBlob.content, blobContent);
+
+      newBlob.free();
+    });
+
+    test('throws when creating new blob from invalid path', () {
+      expect(
+        () => Blob.createFromWorkdir(repo, 'invalid/path.txt'),
+        throwsA(isA<LibGit2Error>()),
+      );
+    });
+
+    test(
+        'throws when creating new blob from path that is outside of working directory',
+        () {
+      final outsideFile =
+          File('${Directory.current.absolute.path}/test/blob_test.dart');
+      expect(
+        () => Blob.createFromWorkdir(repo, outsideFile.path),
+        throwsA(isA<LibGit2Error>()),
+      );
+    });
+
+    test('successfully creates new blob from file at provided path', () {
+      final outsideFile =
+          File('${Directory.current.absolute.path}/test/blob_test.dart');
+      final oid = Blob.createFromDisk(repo, outsideFile.path);
+      final newBlob = Blob.lookup(repo, oid);
+
+      expect(newBlob, isA<Blob>());
+      expect(newBlob.isBinary, false);
+
+      newBlob.free();
+    });
+  });
+}