Initial implementation of an elasticsearch indexer in Go

Closes #1 (closed)

indexer/blob.go

@@ -6,6 +6,8 @@ import (
 	"io/ioutil"
 	"srcd.works/go-git.v4/plumbing/object"
+
+	"gitlab.com/gitlab-org/es-git-go/linguist"
 )
 var (
@@ -93,17 +95,26 @@ func (i *Indexer) BuildBlob(file *object.File, commitSHA string) (*Blob, error)
 		Content:   content,
 		Path:      file.Name,
 		Filename:  file.Name,
-		Language:  DetectLanguage(b),
+		Language:  DetectLanguage(file.Name, b),
 	}, nil
 }
-// FIXME: implement this
-func DetectLanguage(data []byte) string {
+// DetectLanguage returns a string describing the language of the file. This is
+// programming language, rather than natural language.
+//
+// If no language is detected, "Text" is returned.
+func DetectLanguage(filename string, data []byte) string {
+	lang := linguist.DetectLanguage(filename, data)
+	if lang != nil {
+		return lang.Name
+	}
+
 	return "Text"
 }
-// Check whether the passed-in data contains a NUL byte. Only scan the start of
-// large blobs. This is the same test performed by git to check text/binary
+// DetectBinary checks whether the passed-in data contains a NUL byte. Only scan
+// the start of large blobs. This is the same test performed by git to check
+// text/binary
 func DetectBinary(data []byte) bool {
 	searchLimit := binarySearchLimit
 	if len(data) < searchLimit {