plumbing: object, expose ErrEntryNotFound in FindEntry. Fixes #883

FindEntry will return ErrDirNotFound if the directory doesn't exist. But
it doesn't return a public error if the entry itself is missing.  This
exposes the internal error ErrEntryNotFound, so users can
programmatically check for this condition.

Signed-off-by: James Ravn <[email protected]>

Author: jsravn

plumbing/object/tree.go

@@ -25,6 +25,7 @@ var (
 	ErrMaxTreeDepth      = errors.New("maximum tree depth exceeded")
 	ErrFileNotFound      = errors.New("file not found")
 	ErrDirectoryNotFound = errors.New("directory not found")
+	ErrEntryNotFound     = errors.New("entry not found")
 )
 
 // Tree is basically like a directory - it references a bunch of other trees
@@ -166,16 +167,14 @@ func (t *Tree) dir(baseName string) (*Tree, error) {
 	return tree, err
 }
 
-var errEntryNotFound = errors.New("entry not found")
-
 func (t *Tree) entry(baseName string) (*TreeEntry, error) {
 	if t.m == nil {
 		t.buildMap()
 	}
 
 	entry, ok := t.m[baseName]
 	if !ok {
-		return nil, errEntryNotFound
+		return nil, ErrEntryNotFound
 	}
 
 	return entry, nil

plumbing/object/tree_test.go

@@ -114,6 +114,12 @@ func (s *TreeSuite) TestFindEntry(c *C) {
 	c.Assert(e.Name, Equals, "foo.go")
 }
 
+func (s *TreeSuite) TestFindEntryNotFound(c *C) {
+	e, err := s.Tree.FindEntry("not-found")
+	c.Assert(e, IsNil)
+	c.Assert(err, Equals, ErrEntryNotFound)
+}
+
 // Overrides returned plumbing.EncodedObject for given hash.
 // Otherwise, delegates to actual storer to get real object
 type fakeStorer struct {