From a6d43638bd8d79cba34dd83d4abea9401b183161 Mon Sep 17 00:00:00 2001
From: Thomas Roseman <roseman.tom@gmail.com>
Date: Fri, 22 Aug 2025 20:56:54 +0000
Subject: [PATCH] Includes the yaml version directive as part of the known
 headers set.

---
 main.go                     |  1 +
 testdata/expected/file.yaml | 19 +++++++++++++++++++
 testdata/initial/file.yaml  |  5 +++++
 3 files changed, 25 insertions(+)
 create mode 100644 testdata/expected/file.yaml
 create mode 100644 testdata/initial/file.yaml

diff --git a/main.go b/main.go
index 9e42e8a..3b77ce1 100644
--- a/main.go
+++ b/main.go
@@ -393,6 +393,7 @@ var head = []string{
 	"<?php",                    // PHP opening tag
 	"# escape",                 // Dockerfile directive https://docs.docker.com/engine/reference/builder/#parser-directives
 	"# syntax",                 // Dockerfile directive https://docs.docker.com/engine/reference/builder/#parser-directives
+	"%YAML ",                   // YAML version directive https://yaml.org/spec/1.2.2/#681-yaml-directives
 }
 
 func hashBang(b []byte) []byte {
diff --git a/testdata/expected/file.yaml b/testdata/expected/file.yaml
new file mode 100644
index 0000000..21c7545
--- /dev/null
+++ b/testdata/expected/file.yaml
@@ -0,0 +1,19 @@
+# Copyright 2018 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+%YAML 1.2
+---
+root:
+  one: "one"
+  two: {}
\ No newline at end of file
diff --git a/testdata/initial/file.yaml b/testdata/initial/file.yaml
new file mode 100644
index 0000000..55d9ec9
--- /dev/null
+++ b/testdata/initial/file.yaml
@@ -0,0 +1,5 @@
+%YAML 1.2
+---
+root:
+  one: "one"
+  two: {}
\ No newline at end of file