refactor(checkout)!: move checkout related methods into Checkout class (#42)

test/checkout_test.dart

@@ -27,8 +27,8 @@ void main() {
       File(p.join(tmpDir.path, 'feature_file')).writeAsStringSync('edit');
       expect(repo.status, contains('feature_file'));
 
-      repo.checkout(
-        target: 'HEAD',
+      Checkout.head(
+        repo: repo,
         strategy: {GitCheckout.force},
         paths: ['feature_file'],
       );
@@ -39,8 +39,8 @@ void main() {
         'throws when trying to checkout head with invalid alternative '
         'directory', () {
       expect(
-        () => repo.checkout(
-          target: 'HEAD',
+        () => Checkout.head(
+          repo: repo,
           directory: 'not/there',
         ),
         throwsA(isA<LibGit2Error>()),
@@ -51,7 +51,8 @@ void main() {
       File(p.join(repo.workdir, 'feature_file')).writeAsStringSync('edit');
       expect(repo.status, contains('feature_file'));
 
-      repo.checkout(
+      Checkout.index(
+        repo: repo,
         strategy: {
           GitCheckout.force,
           GitCheckout.conflictStyleMerge,
@@ -65,7 +66,7 @@ void main() {
         'throws when trying to checkout index with invalid alternative '
         'directory', () {
       expect(
-        () => repo.checkout(directory: 'not/there'),
+        () => Checkout.index(repo: repo, directory: 'not/there'),
         throwsA(isA<LibGit2Error>()),
       );
     });
@@ -78,12 +79,12 @@ void main() {
         false,
       );
 
-      repo.checkout(target: 'refs/heads/feature');
+      Checkout.reference(repo: repo, name: 'refs/heads/feature');
       final featureHead = Commit.lookup(repo: repo, oid: repo['5aecfa0']);
       final featureTree = featureHead.tree;
       final repoHead = repo.head;
-      expect(repoHead.target, featureHead.oid);
-      expect(repo.status, isEmpty);
+      // does not change HEAD
+      expect(repoHead.target, isNot(featureHead.oid));
       expect(
         featureTree.entries.any((e) => e.name == 'another_feature_file'),
         true,
@@ -100,8 +101,9 @@ void main() {
         'throws when trying to checkout reference with invalid alternative '
         'directory', () {
       expect(
-        () => repo.checkout(
-          target: 'refs/heads/feature',
+        () => Checkout.reference(
+          repo: repo,
+          name: 'refs/heads/feature',
           directory: 'not/there',
         ),
         throwsA(isA<LibGit2Error>()),
@@ -113,11 +115,11 @@ void main() {
       expect(index.find('another_feature_file'), equals(false));
 
       final featureHead = Commit.lookup(repo: repo, oid: repo['5aecfa0']);
-      repo.checkout(target: featureHead.oid);
+      Checkout.commit(repo: repo, commit: featureHead);
 
       final repoHead = repo.head;
-      expect(repoHead.target, featureHead.oid);
-      expect(repo.status, isEmpty);
+      // does not change HEAD
+      expect(repoHead.target, isNot(featureHead.oid));
       expect(index.find('another_feature_file'), equals(true));
 
       repoHead.free();
@@ -127,10 +129,14 @@ void main() {
 
     test('checkouts commit with provided path', () {
       final featureHead = Commit.lookup(repo: repo, oid: repo['5aecfa0']);
-      repo.checkout(target: featureHead.oid, paths: ['another_feature_file']);
+      Checkout.commit(
+        repo: repo,
+        commit: featureHead,
+        paths: ['another_feature_file'],
+      );
 
       final repoHead = repo.head;
-      // When path is provided HEAD will not be set to target;
+      // does not change HEAD
       expect(repoHead.target, isNot(featureHead.oid));
       expect(
         repo.status,
@@ -143,6 +149,23 @@ void main() {
       featureHead.free();
     });
 
+    test(
+        'throws when trying to checkout commit with invalid alternative '
+        'directory', () {
+      final commit = Commit.lookup(repo: repo, oid: repo['5aecfa0']);
+
+      expect(
+        () => Checkout.commit(
+          repo: repo,
+          commit: commit,
+          directory: 'not/there',
+        ),
+        throwsA(isA<LibGit2Error>()),
+      );
+
+      commit.free();
+    });
+
     test('checkouts with alrenative directory', () {
       final altDir = Directory(p.join(Directory.systemTemp.path, 'alt_dir'));
       // making sure there is no directory
@@ -152,7 +175,11 @@ void main() {
       altDir.createSync();
       expect(altDir.listSync().length, 0);
 
-      repo.checkout(target: 'refs/heads/feature', directory: altDir.path);
+      Checkout.reference(
+        repo: repo,
+        name: 'refs/heads/feature',
+        directory: altDir.path,
+      );
       expect(altDir.listSync().length, isNot(0));
 
       altDir.deleteSync(recursive: true);
@@ -165,8 +192,9 @@ void main() {
       ).target;
 
       expect(repo.status, isEmpty);
-      repo.checkout(
-        target: 'refs/heads/feature',
+      Checkout.reference(
+        repo: repo,
+        name: 'refs/heads/feature',
         paths: ['another_feature_file'],
       );
       expect(
@@ -175,7 +203,7 @@ void main() {
           'another_feature_file': {GitStatus.indexNew}
         },
       );
-      // When path is provided HEAD will not be set to target;
+      // does not change HEAD
       expect(repo.head.target, isNot(featureTip));
     });
 
@@ -185,8 +213,9 @@ void main() {
       final file = File(p.join(repo.workdir, 'another_feature_file'));
       expect(file.existsSync(), false);
 
-      repo.checkout(
-        target: 'refs/heads/feature',
+      Checkout.reference(
+        repo: repo,
+        name: 'refs/heads/feature',
         strategy: {GitCheckout.dryRun},
       );
       expect(index.length, 4);
@@ -194,9 +223,5 @@ void main() {
 
       index.free();
     });
-
-    test('throws when provided target is not String or Oid', () {
-      expect(() => repo.checkout(target: 1), throwsA(isA<ArgumentError>()));
-    });
   });
 }