Add 'warning: is unversioned' header to all docs

Mungedocs will keep this updated in head, and it will get stricken from
releases.

cmd/mungedocs/unversioned_warning_test.go

@@ -0,0 +1,64 @@
+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+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.
+*/
+
+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestUnversionedWarning(t *testing.T) {
+	warningBlock := beginUnversionedWarning + "\n" + unversionedWarning + "\n" + endUnversionedWarning + "\n"
+	var cases = []struct {
+		in  string
+		out string
+	}{
+		{"", warningBlock},
+		{
+			"Foo\nBar\n",
+			warningBlock + "Foo\nBar\n",
+		},
+		{
+			"Foo\n<!-- TAG IS_VERSIONED -->\nBar",
+			"Foo\n<!-- TAG IS_VERSIONED -->\nBar",
+		},
+		{
+			beginUnversionedWarning + "\n" + endUnversionedWarning + "\n",
+			warningBlock,
+		},
+		{
+			beginUnversionedWarning + "\n" + "something\n" + endUnversionedWarning + "\n",
+			warningBlock,
+		},
+		{
+			"Foo\n" + beginUnversionedWarning + "\n" + endUnversionedWarning + "\nBar\n",
+			"Foo\n" + warningBlock + "Bar\n",
+		},
+		{
+			"Foo\n" + warningBlock + "Bar\n",
+			"Foo\n" + warningBlock + "Bar\n",
+		},
+	}
+	for i, c := range cases {
+		actual, err := updateUnversionedWarning("filename.md", []byte(c.in))
+		assert.NoError(t, err)
+		if string(actual) != c.out {
+			t.Errorf("case[%d]: expected %q got %q", i, c.out, string(actual))
+		}
+	}
+}