test(stash): move tests to separate file

test/stash_test.dart

@@ -0,0 +1,95 @@
+import 'dart:io';
+import 'package:test/test.dart';
+import 'package:libgit2dart/libgit2dart.dart';
+import 'helpers/util.dart';
+
+void main() {
+  late Repository repo;
+  late Signature stasher;
+  final tmpDir = '${Directory.systemTemp.path}/patch_testrepo/';
+
+  setUp(() async {
+    if (await Directory(tmpDir).exists()) {
+      await Directory(tmpDir).delete(recursive: true);
+    }
+    await copyRepo(
+      from: Directory('test/assets/testrepo/'),
+      to: await Directory(tmpDir).create(),
+    );
+    repo = Repository.open(tmpDir);
+    stasher = Signature.create(
+      name: 'Stasher',
+      email: 'stasher@email.com',
+    );
+  });
+
+  tearDown(() async {
+    stasher.free();
+    repo.free();
+    await Directory(tmpDir).delete(recursive: true);
+  });
+
+  group('Stash', () {
+    test('successfully saves changes to stash', () {
+      File('${tmpDir}file').writeAsStringSync(
+        'edit',
+        mode: FileMode.append,
+      );
+
+      repo.stash(stasher: stasher, includeUntracked: true);
+      expect(repo.status.isEmpty, true);
+    });
+
+    test('successfully applies changes from stash', () {
+      File('${tmpDir}file').writeAsStringSync(
+        'edit',
+        mode: FileMode.append,
+      );
+
+      repo.stash(stasher: stasher);
+      expect(repo.status.isEmpty, true);
+
+      repo.stashApply();
+      expect(repo.status, contains('file'));
+    });
+
+    test('successfully drops stash', () {
+      File('${tmpDir}file').writeAsStringSync(
+        'edit',
+        mode: FileMode.append,
+      );
+
+      repo.stash(stasher: stasher);
+      final stash = repo.stashList.first;
+      repo.stashDrop(stash.index);
+      expect(() => repo.stashApply(), throwsA(isA<LibGit2Error>()));
+    });
+
+    test('successfully pops from stash', () {
+      File('${tmpDir}file').writeAsStringSync(
+        'edit',
+        mode: FileMode.append,
+      );
+
+      repo.stash(stasher: stasher);
+      repo.stashPop();
+      expect(repo.status, contains('file'));
+      expect(() => repo.stashApply(), throwsA(isA<LibGit2Error>()));
+    });
+
+    test('returns list of stashes', () {
+      File('${tmpDir}file').writeAsStringSync(
+        'edit',
+        mode: FileMode.append,
+      );
+
+      repo.stash(stasher: stasher, message: 'WIP');
+
+      final stash = repo.stashList.first;
+
+      expect(repo.stashList.length, 1);
+      expect(stash.index, 0);
+      expect(stash.message, 'On master: WIP');
+    });
+  });
+}