feat(branch): add bindings and api

lib/src/branch.dart

@@ -0,0 +1,133 @@
+import 'dart:ffi';
+import 'bindings/libgit2_bindings.dart';
+import 'bindings/branch.dart' as bindings;
+import 'bindings/reference.dart' as reference_bindings;
+import 'commit.dart';
+import 'reference.dart';
+import 'repository.dart';
+import 'oid.dart';
+import 'git_types.dart';
+import 'util.dart';
+
+class Branches {
+  /// Initializes a new instance of the [Branches] class
+  /// from provided [Repository] object.
+  Branches(Repository repo) {
+    _repoPointer = repo.pointer;
+  }
+
+  /// Pointer to memory address for allocated repository object.
+  late final Pointer<git_repository> _repoPointer;
+
+  /// Returns a list of all branches that can be found in a repository.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  List<String> list() => bindings.list(_repoPointer, GitBranch.all.value);
+
+  /// Returns a list of local branches that can be found in a repository.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  List<String> get local => bindings.list(_repoPointer, GitBranch.local.value);
+
+  /// Returns a list of remote branches that can be found in a repository.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  List<String> get remote =>
+      bindings.list(_repoPointer, GitBranch.remote.value);
+
+  /// Lookups a branch by its name in a repository.
+  ///
+  /// The generated reference must be freed. The branch name will be checked for validity.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  Branch operator [](String branchName) {
+    final ref = Reference(
+        _repoPointer, reference_bindings.lookupDWIM(_repoPointer, branchName));
+    late final GitBranch type;
+    ref.isBranch ? type = GitBranch.local : GitBranch.remote;
+    ref.free();
+
+    return Branch(bindings.lookup(_repoPointer, branchName, type.value));
+  }
+
+  /// Creates a new branch pointing at a [target] commit.
+  ///
+  /// A new direct reference will be created pointing to this target commit.
+  /// If [force] is true and a reference already exists with the given name, it'll be replaced.
+  ///
+  /// The returned reference must be freed.
+  ///
+  /// The branch name will be checked for validity.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  Reference create({
+    required String name,
+    required Commit target,
+    bool force = false,
+  }) {
+    final result = bindings.create(
+      _repoPointer,
+      name,
+      target.pointer,
+      force,
+    );
+
+    return Reference(_repoPointer, result);
+  }
+}
+
+class Branch {
+  /// Initializes a new instance of [Branch] class from provided pointer to
+  /// branch object in memory.
+  ///
+  /// Should be freed with `free()` to release allocated memory.
+  Branch(this._branchPointer) {
+    libgit2.git_libgit2_init();
+  }
+
+  /// Pointer to memory address for allocated branch object.
+  late final Pointer<git_reference> _branchPointer;
+
+  /// Returns the OID pointed to by a branch.
+  ///
+  /// Throws an exception if error occured.
+  Oid get target => Oid(reference_bindings.target(_branchPointer));
+
+  /// Deletes an existing branch reference.
+  ///
+  /// Note that if the deletion succeeds, the reference object will not be valid anymore,
+  /// and will be freed.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  void delete() => bindings.delete(_branchPointer);
+
+  /// Renames an existing local branch reference.
+  ///
+  /// The new branch name will be checked for validity.
+  ///
+  /// Note that if the move succeeds, the old reference object will not be valid anymore,
+  /// and will be freed immediately.
+  ///
+  /// If [force] is true, existing branch will be overwritten.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  Branch rename({required String newName, bool force = false}) {
+    return Branch(bindings.rename(_branchPointer, newName, force));
+  }
+
+  /// Determines if HEAD points to the given branch.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  bool get isHead => bindings.isHead(_branchPointer);
+
+  /// Returns the branch name.
+  ///
+  /// Given a reference object, this will check that it really is a branch
+  /// (ie. it lives under "refs/heads/" or "refs/remotes/"), and return the branch part of it.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  String get name => bindings.name(_branchPointer);
+
+  /// Releases memory allocated for branch object.
+  void free() => bindings.free(_branchPointer);
+}