adds Tree method to Tree (#224)

This patch adds a new method to the Tree object that allows you to get a child tree from a parent tree by its relative name.

Before this patch, this was only possible with files, using the File method.

The new Tree method has a similar signature to the old File method for consistency.

1 files changed, 34 insertions, 0 deletions

diff --git a/plumbing/object/tree_test.go b/plumbing/object/tree_test.go
index 00601c1..9b9614b 100644
--- a/plumbing/object/tree_test.go
+++ b/plumbing/object/tree_test.go
@@ -48,6 +48,31 @@ func (s *TreeSuite) TestType(c *C) {
 	c.Assert(s.Tree.Type(), Equals, plumbing.TreeObject)
 }
 
+func (s *TreeSuite) TestTree(c *C) {
+	expectedEntry, ok := s.Tree.m["vendor"]
+	c.Assert(ok, Equals, true)
+	expected := expectedEntry.Hash
+
+	obtainedTree, err := s.Tree.Tree("vendor")
+	c.Assert(err, IsNil)
+	c.Assert(obtainedTree.Hash, Equals, expected)
+}
+
+func (s *TreeSuite) TestTreeNotFound(c *C) {
+	d, err := s.Tree.Tree("not-found")
+	c.Assert(d, IsNil)
+	c.Assert(err, Equals, ErrDirectoryNotFound)
+}
+
+func (s *TreeSuite) TestTreeFailsWithExistingFiles(c *C) {
+	_, err := s.Tree.File("LICENSE")
+	c.Assert(err, IsNil)
+
+	d, err := s.Tree.Tree("LICENSE")
+	c.Assert(d, IsNil)
+	c.Assert(err, Equals, ErrDirectoryNotFound)
+}
+
 func (s *TreeSuite) TestFile(c *C) {
 	f, err := s.Tree.File("LICENSE")
 	c.Assert(err, IsNil)
@@ -60,6 +85,15 @@ func (s *TreeSuite) TestFileNotFound(c *C) {
 	c.Assert(err, Equals, ErrFileNotFound)
 }
 
+func (s *TreeSuite) TestFileFailsWithExistingTrees(c *C) {
+	_, err := s.Tree.Tree("vendor")
+	c.Assert(err, IsNil)
+
+	f, err := s.Tree.File("vendor")
+	c.Assert(f, IsNil)
+	c.Assert(err, Equals, ErrFileNotFound)
+}
+
 func (s *TreeSuite) TestFiles(c *C) {
 	var count int
 	err := s.Tree.Files().ForEach(func(f *File) error {