Add `Repository.CreateCommitBuffer` (#781)

This commit adds the Go binding for `git_commit_create_buffer`. This
will be used to support the 1.2.0 commit create callback.

1 files changed, 54 insertions, 0 deletions

diff --git a/repository_test.go b/repository_test.go
index e403aa9..60758c1 100644
--- a/repository_test.go
+++ b/repository_test.go
@@ -5,6 +5,60 @@ import (
 	"time"
 )
 
+func TestCreateCommitBuffer(t *testing.T) {
+	t.Parallel()
+	repo := createTestRepo(t)
+	defer cleanupTestRepo(t, repo)
+
+	loc, err := time.LoadLocation("Europe/Berlin")
+	checkFatal(t, err)
+	sig := &Signature{
+		Name:  "Rand Om Hacker",
+		Email: "[email protected]",
+		When:  time.Date(2013, 03, 06, 14, 30, 0, 0, loc),
+	}
+
+	idx, err := repo.Index()
+	checkFatal(t, err)
+	err = idx.AddByPath("README")
+	checkFatal(t, err)
+	err = idx.Write()
+	checkFatal(t, err)
+	treeId, err := idx.WriteTree()
+	checkFatal(t, err)
+
+	message := "This is a commit\n"
+	tree, err := repo.LookupTree(treeId)
+	checkFatal(t, err)
+
+	for encoding, expected := range map[MessageEncoding]string{
+		MessageEncodingUTF8: `tree b7119b11e8ef7a1a5a34d3ac87f5b075228ac81e
+author Rand Om Hacker <[email protected]> 1362576600 +0100
+committer Rand Om Hacker <[email protected]> 1362576600 +0100
+
+This is a commit
+`,
+		MessageEncoding("ASCII"): `tree b7119b11e8ef7a1a5a34d3ac87f5b075228ac81e
+author Rand Om Hacker <[email protected]> 1362576600 +0100
+committer Rand Om Hacker <[email protected]> 1362576600 +0100
+encoding ASCII
+
+This is a commit
+`,
+	} {
+		encoding := encoding
+		expected := expected
+		t.Run(string(encoding), func(t *testing.T) {
+			buf, err := repo.CreateCommitBuffer(sig, sig, encoding, message, tree)
+			checkFatal(t, err)
+
+			if expected != string(buf) {
+				t.Errorf("mismatched commit buffer, expected %v, got %v", expected, string(buf))
+			}
+		})
+	}
+}
+
 func TestCreateCommitFromIds(t *testing.T) {
 	t.Parallel()
 	repo := createTestRepo(t)