From 99ebc9c9db7bceb8623073e894533b978d7b7c8a Mon Sep 17 00:00:00 2001
From: CrazyMax <google@crazymax.dev>
Date: Mon, 9 Aug 2021 21:04:55 +0200
Subject: [PATCH] Update Dockerfile handling to keep parser directives at the
 top

Signed-off-by: CrazyMax <google@crazymax.dev>
---
 main.go                                        |  2 ++
 main_test.go                                   |  2 ++
 .../{file.Dockerfile => file1.Dockerfile}      |  0
 testdata/expected/file2.Dockerfile             | 17 +++++++++++++++++
 testdata/expected/file3.Dockerfile             | 18 ++++++++++++++++++
 .../{file.Dockerfile => file1.Dockerfile}      |  0
 testdata/initial/file2.Dockerfile              |  3 +++
 testdata/initial/file3.Dockerfile              |  4 ++++
 8 files changed, 46 insertions(+)
 rename testdata/expected/{file.Dockerfile => file1.Dockerfile} (100%)
 create mode 100644 testdata/expected/file2.Dockerfile
 create mode 100644 testdata/expected/file3.Dockerfile
 rename testdata/initial/{file.Dockerfile => file1.Dockerfile} (100%)
 create mode 100644 testdata/initial/file2.Dockerfile
 create mode 100644 testdata/initial/file3.Dockerfile

diff --git a/main.go b/main.go
index f5721e4..5e4fcd7 100644
--- a/main.go
+++ b/main.go
@@ -296,6 +296,8 @@ var head = []string{
 	"# encoding:",              // Ruby encoding
 	"# frozen_string_literal:", // Ruby interpreter instruction
 	"<?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
 }
 
 func hashBang(b []byte) []byte {
diff --git a/main_test.go b/main_test.go
index c6ce68a..5be8eb4 100644
--- a/main_test.go
+++ b/main_test.go
@@ -242,6 +242,8 @@ func TestAddLicense(t *testing.T) {
 		{"# encoding: UTF-8\ncontent", "# encoding: UTF-8\n// HYS\n\ncontent", true},
 		{"# frozen_string_literal: true\ncontent", "# frozen_string_literal: true\n// HYS\n\ncontent", true},
 		{"<?php\ncontent", "<?php\n// HYS\n\ncontent", true},
+		{"# escape: `\ncontent", "# escape: `\n// HYS\n\ncontent", true},
+		{"# syntax: docker/dockerfile:1.3\ncontent", "# syntax: docker/dockerfile:1.3\n// HYS\n\ncontent", true},
 
 		// ensure files with existing license or generated files are
 		// skipped. No need to test all permutations of these, since
diff --git a/testdata/expected/file.Dockerfile b/testdata/expected/file1.Dockerfile
similarity index 100%
rename from testdata/expected/file.Dockerfile
rename to testdata/expected/file1.Dockerfile
diff --git a/testdata/expected/file2.Dockerfile b/testdata/expected/file2.Dockerfile
new file mode 100644
index 0000000..4ace5da
--- /dev/null
+++ b/testdata/expected/file2.Dockerfile
@@ -0,0 +1,17 @@
+# syntax=docker/dockerfile:1.3
+# 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.
+
+FROM scratch
+CMD ["echo", "hello world"]
diff --git a/testdata/expected/file3.Dockerfile b/testdata/expected/file3.Dockerfile
new file mode 100644
index 0000000..3df599b
--- /dev/null
+++ b/testdata/expected/file3.Dockerfile
@@ -0,0 +1,18 @@
+# escape=`
+# 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.
+
+FROM microsoft/nanoserver
+COPY testfile.txt c:\
+RUN dir c:\
diff --git a/testdata/initial/file.Dockerfile b/testdata/initial/file1.Dockerfile
similarity index 100%
rename from testdata/initial/file.Dockerfile
rename to testdata/initial/file1.Dockerfile
diff --git a/testdata/initial/file2.Dockerfile b/testdata/initial/file2.Dockerfile
new file mode 100644
index 0000000..92389b8
--- /dev/null
+++ b/testdata/initial/file2.Dockerfile
@@ -0,0 +1,3 @@
+# syntax=docker/dockerfile:1.3
+FROM scratch
+CMD ["echo", "hello world"]
diff --git a/testdata/initial/file3.Dockerfile b/testdata/initial/file3.Dockerfile
new file mode 100644
index 0000000..fe26a12
--- /dev/null
+++ b/testdata/initial/file3.Dockerfile
@@ -0,0 +1,4 @@
+# escape=`
+FROM microsoft/nanoserver
+COPY testfile.txt c:\
+RUN dir c:\