Refactor branch list using src-d/go-git and add GetRefs function (#133)

* Refactor branch list using src-d/go-git and add GetRefs function

* Fix copyright

* Fix to reuse ObjectType

* Add function to filter refs by prefix

* Fix import order

* Optimize if structure

Author: lafriks

Diff for: Gopkg.lock

@@ -32,3 +32,7 @@
 [prune]
   go-tests = true
   unused-packages = true
+
+[[constraint]]
+  name = "gopkg.in/src-d/go-git.v4"
+  version = "4.7.1"

Diff for: Gopkg.toml

@@ -0,0 +1,18 @@
+// Copyright 2018 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+// Reference represents a Git ref.
+type Reference struct {
+	Name   string
+	repo   *Repository
+	Object SHA1 // The id of this commit object
+	Type   string
+}
+
+// Commit return the commit of the reference
+func (ref *Reference) Commit() (*Commit, error) {
+	return ref.repo.getCommit(ref.Object)
+}

Diff for: ref.go

@@ -1,4 +1,5 @@
 // Copyright 2015 The Gogs Authors. All rights reserved.
+// Copyright 2018 The Gitea Authors. All rights reserved.
 // Use of this source code is governed by a MIT-style
 // license that can be found in the LICENSE file.
 
@@ -7,6 +8,9 @@ package git
 import (
 	"fmt"
 	"strings"
+
+	"gopkg.in/src-d/go-git.v4"
+	"gopkg.in/src-d/go-git.v4/plumbing"
 )
 
 // BranchPrefix base dir of the branch information file store on git
@@ -60,16 +64,23 @@ func (repo *Repository) SetDefaultBranch(name string) error {
 
 // GetBranches returns all branches of the repository.
 func (repo *Repository) GetBranches() ([]string, error) {
-	stdout, err := NewCommand("for-each-ref", "--format=%(refname)", BranchPrefix).RunInDir(repo.Path)
+	r, err := git.PlainOpen(repo.Path)
 	if err != nil {
 		return nil, err
 	}
 
-	refs := strings.Split(stdout, "\n")
-	branches := make([]string, len(refs)-1)
-	for i, ref := range refs[:len(refs)-1] {
-		branches[i] = strings.TrimPrefix(ref, BranchPrefix)
+	branchIter, err := r.Branches()
+	if err != nil {
+		return nil, err
 	}
+	branches := make([]string, 0)
+	if err = branchIter.ForEach(func(branch *plumbing.Reference) error {
+		branches = append(branches, branch.Name().Short())
+		return nil
+	}); err != nil {
+		return nil, err
+	}
+
 	return branches, nil
 }
 

Diff for: repo_branch.go

@@ -0,0 +1,39 @@
+// Copyright 2018 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRepository_GetBranches(t *testing.T) {
+	bareRepo1Path := filepath.Join(testReposDir, "repo1_bare")
+	bareRepo1, err := OpenRepository(bareRepo1Path)
+	assert.NoError(t, err)
+
+	branches, err := bareRepo1.GetBranches()
+
+	assert.NoError(t, err)
+	assert.Len(t, branches, 3)
+	assert.ElementsMatch(t, []string{"branch1", "branch2", "master"}, branches)
+}
+
+func BenchmarkRepository_GetBranches(b *testing.B) {
+	bareRepo1Path := filepath.Join(testReposDir, "repo1_bare")
+	bareRepo1, err := OpenRepository(bareRepo1Path)
+	if err != nil {
+		b.Fatal(err)
+	}
+
+	for i := 0; i < b.N; i++ {
+		_, err := bareRepo1.GetBranches()
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+}

Diff for: repo_branch_test.go

@@ -11,7 +11,7 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func TestRepository_GetBranches(t *testing.T) {
+func TestRepository_GetCommitBranches(t *testing.T) {
 	bareRepo1Path := filepath.Join(testReposDir, "repo1_bare")
 	bareRepo1, err := OpenRepository(bareRepo1Path)
 	assert.NoError(t, err)