create destination directory

mmv.go

@@ -14,13 +14,31 @@ func Rename(files map[string]string) error {
 		return err
 	}
 	for _, r := range rs {
-		if err := os.Rename(r.src, r.dst); err != nil {
+		if err := doRename(r.src, r.dst); err != nil {
 			return err
 		}
 	}
 	return nil
 }
 
+// rename with creating the destination directory
+func doRename(src, dst string) (err error) {
+	// first of all, try renaming the file, which will succeed in most cases
+	if err = os.Rename(src, dst); err != nil && os.IsNotExist(err) {
+		// check the source file existence to exit without creating the destination
+		// directory when the both source file and destination directory do not exist
+		if _, err := os.Stat(src); err == nil {
+			// create the destination directory
+			if err := os.MkdirAll(filepath.Dir(dst), 0755); err != nil {
+				return err
+			}
+			// try renaming again
+			return os.Rename(src, dst)
+		}
+	}
+	return
+}
+
 type rename struct {
 	src, dst string
 }

mmv_test.go

@@ -233,6 +233,25 @@ func TestRename(t *testing.T) {
 			},
 			err: &sameDestinationError{"foo"},
 		},
+		{
+			name: "create destination directory",
+			files: map[string]string{
+				"foo": "x/foo",
+				"bar": "x/bar",
+				"baz": "a/b/c/baz",
+			},
+			count: 3,
+			contents: map[string]string{
+				"foo": "0",
+				"bar": "1",
+				"baz": "2",
+			},
+			expected: map[string]string{
+				"x/foo":     "0",
+				"x/bar":     "1",
+				"a/b/c/baz": "2",
+			},
+		},
 	}
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {