format/diff: unified diff encoder and public API

- Added Patch interface
- Added a Unified Diff encoder from Patches
- Added Change method to generate Patches
- Added Changes method to generate Patches
- Added Tree method to generate Patches
- Added Commit method to generate Patches

1 files changed, 12 insertions, 0 deletions

diff --git a/plumbing/object/file.go b/plumbing/object/file.go
index 6932c31..79f57fe 100644
--- a/plumbing/object/file.go
+++ b/plumbing/object/file.go
@@ -7,6 +7,7 @@ import (
 
 	"gopkg.in/src-d/go-git.v4/plumbing/filemode"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
+	"gopkg.in/src-d/go-git.v4/utils/binary"
 	"gopkg.in/src-d/go-git.v4/utils/ioutil"
 )
 
@@ -42,6 +43,17 @@ func (f *File) Contents() (content string, err error) {
 	return buf.String(), nil
 }
 
+// IsBinary returns if the file is binary or not
+func (f *File) IsBinary() (bool, error) {
+	reader, err := f.Reader()
+	if err != nil {
+		return false, err
+	}
+	defer ioutil.CheckClose(reader, &err)
+
+	return binary.IsBinary(reader)
+}
+
 // Lines returns a slice of lines from the contents of a file, stripping
 // all end of line characters. If the last line is empty (does not end
 // in an end of line), it is also stripped.