follow cursor when staging and unstaging a file rename

pkg/commands/file.go

@@ -1,6 +1,10 @@
 package commands
 
-import "strings"
+import (
+	"strings"
+
+	"github.com/jesseduffield/lazygit/pkg/utils"
+)
 
 // File : A file from git status
 // duplicating this for now
@@ -17,6 +21,18 @@ type File struct {
 	ShortStatus             string // e.g. 'AD', ' A', 'M ', '??'
 }
 
+const RENAME_SEPARATOR = " -> "
+
 func (f *File) IsRename() bool {
-	return strings.Contains(f.Name, " -> ")
+	return strings.Contains(f.Name, RENAME_SEPARATOR)
+}
+
+// Names returns an array containing just the filename, or in the case of a rename, the after filename and the before filename
+func (f *File) Names() []string {
+	return strings.Split(f.Name, RENAME_SEPARATOR)
+}
+
+// returns true if the file names are the same or if a a file rename includes the filename of the other
+func (f *File) Matches(f2 *File) bool {
+	return utils.StringArraysOverlap(f.Names(), f2.Names())
 }