feat(repository): add ability to initialize repository

lib/src/bindings/repository.dart

@@ -69,6 +69,22 @@ String discover(String startPath, String ceilingDirs) {
   return result;
 }
 
+/// Creates a new Git repository in the given folder.
+///
+/// Throws a [LibGit2Error] if error occured.
+Pointer<git_repository> init(String path, bool isBare) {
+  final out = calloc<Pointer<git_repository>>();
+  final pathC = path.toNativeUtf8().cast<Int8>();
+  final isBareC = isBare ? 1 : 0;
+  final error = libgit2.git_repository_init(out, pathC, isBareC);
+
+  if (error < 0) {
+    throw LibGit2Error(libgit2.git_error_last());
+  }
+
+  return out.value;
+}
+
 /// Returns the path to the `.git` folder for normal repositories or the
 /// repository itself for bare repositories.
 String path(Pointer<git_repository> repo) {

lib/src/repository.dart

@@ -10,12 +10,24 @@ import 'util.dart';
 
 /// A Repository is the primary interface into a git repository
 class Repository {
+  /// Initializes a new instance of the [Repository] class by creating a new
+  /// Git repository in the given folder.
+  ///
+  /// Should be freed with `free()` to release allocated memory.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  Repository.init(String path, {bool isBare = false}) {
+    libgit2.git_libgit2_init();
+
+    _repoPointer = bindings.init(path, isBare);
+  }
+
   /// Initializes a new instance of the [Repository] class.
   /// For a standard repository, [path] should either point to the `.git` folder
   /// or to the working directory. For a bare repository, [path] should directly
   /// point to the repository folder.
   ///
-  /// [Repository] object should be close with [free] function to release allocated memory.
+  /// Should be freed with `free()` to release allocated memory.
   ///
   /// Throws a [LibGit2Error] if error occured.
   Repository.open(String path) {

test/repository_test.dart

@@ -14,6 +14,36 @@ void main() {
       );
     });
 
+    group('.init()', () {
+      final initDir = '${Directory.systemTemp.path}/init_repo/';
+
+      setUp(() async {
+        if (await Directory(initDir).exists()) {
+          await Directory(initDir).delete(recursive: true);
+        } else {
+          await Directory(initDir).create();
+        }
+      });
+
+      tearDown(() async {
+        repo.free();
+        await Directory(initDir).delete(recursive: true);
+      });
+
+      test('successfully creates new bare repo at provided path', () {
+        repo = Repository.init(initDir, isBare: true);
+        expect(repo.path, initDir);
+        expect(repo.isBare, true);
+      });
+
+      test('successfully creates new standard repo at provided path', () {
+        repo = Repository.init(initDir);
+        expect(repo.path, '$initDir.git/');
+        expect(repo.isBare, false);
+        expect(repo.isEmpty, true);
+      });
+    });
+
     group('empty', () {
       group('bare', () {
         setUp(() {