feat(reset): add bindings and api

lib/src/bindings/reset.dart

@@ -0,0 +1,29 @@
+import 'dart:ffi';
+import '../error.dart';
+import 'libgit2_bindings.dart';
+import '../util.dart';
+
+/// Sets the current head to the specified commit oid and optionally resets the index
+/// and working tree to match.
+///
+/// SOFT reset means the Head will be moved to the commit.
+///
+/// MIXED reset will trigger a SOFT reset, plus the index will be replaced with the
+/// content of the commit tree.
+///
+/// HARD reset will trigger a MIXED reset and the working directory will be replaced
+/// with the content of the index. (Untracked and ignored files will be left alone, however.)
+///
+/// Throws a [LibGit2Error] if error occured.
+void reset(
+  Pointer<git_repository> repo,
+  Pointer<git_object> target,
+  int resetType,
+  Pointer<git_checkout_options> checkoutOpts,
+) {
+  final error = libgit2.git_reset(repo, target, resetType, checkoutOpts);
+
+  if (error < 0) {
+    throw LibGit2Error(libgit2.git_error_last());
+  }
+}

lib/src/git_types.dart

@@ -578,3 +578,26 @@ class GitCheckout {
   @override
   String toString() => 'GitCheckout.$_name';
 }
+
+/// Kinds of reset operation.
+class GitReset {
+  const GitReset._(this._value, this._name);
+  final int _value;
+  final String _name;
+
+  /// Move the head to the given commit.
+  static const soft = GitReset._(1, 'soft');
+
+  /// [GitReset.soft] plus reset index to the commit.
+  static const mixed = GitReset._(2, 'mixed');
+
+  /// [GitReset.mixed] plus changes in working tree discarded.
+  static const hard = GitReset._(3, 'hard');
+
+  static const List<GitReset> values = [soft, mixed, hard];
+
+  int get value => _value;
+
+  @override
+  String toString() => 'GitReset.$_name';
+}

lib/src/repository.dart

@@ -8,6 +8,7 @@ import 'bindings/object.dart' as object_bindings;
 import 'bindings/status.dart' as status_bindings;
 import 'bindings/commit.dart' as commit_bindings;
 import 'bindings/checkout.dart' as checkout_bindings;
+import 'bindings/reset.dart' as reset_bindings;
 import 'branch.dart';
 import 'commit.dart';
 import 'config.dart';
@@ -705,4 +706,21 @@ class Repository {
       ref.free();
     }
   }
+
+  /// Sets the current head to the specified commit and optionally resets the index
+  /// and working tree to match.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  void reset(String target, GitReset resetType) {
+    final oid = Oid.fromSHA(this, target);
+    final object = object_bindings.lookup(
+      _repoPointer,
+      oid.pointer,
+      GitObject.any.value,
+    );
+
+    reset_bindings.reset(_repoPointer, object, resetType.value, nullptr);
+
+    object_bindings.free(object);
+  }
 }