Add CSS cache busting to templates in release

Makefile

@@ -86,6 +86,7 @@ release : clean ui assets
 	cp -r templates $(BUILDPATH)
 	cp -r pages $(BUILDPATH)
 	cp -r static $(BUILDPATH)
+	scripts/invalidate-css.sh $(BUILDPATH)
 	mkdir $(BUILDPATH)/keys
 	$(MAKE) build-linux
 	mv build/$(BINARY_NAME)-linux-amd64 $(BUILDPATH)/$(BINARY_NAME)

scripts/invalidate-css.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+#
+#	Copyright © 2020 A Bunch Tell LLC.
+#
+#	This file is part of WriteFreely.
+#
+#	WriteFreely is free software: you can redistribute it and/or modify
+#	it under the terms of the GNU Affero General Public License, included
+#	in the LICENSE file in this source code package.
+#
+###############################################################################
+#
+# WriteFreely CSS invalidation script
+#
+# usage: ./invalidate-css.sh <build-directory>
+#
+# This script provides an automated way to invalidate stylesheets cached in the
+# browser. It uses the last git commit hashes of the most frequently modified
+# LESS files in the project and appends them to the stylesheet `href` in all
+# template files.
+#
+# This is designed to be used when building a WriteFreely release.
+#
+###############################################################################
+
+# Get parent build directory from first argument
+buildDir=$1
+
+# Get short hash of each primary LESS file's last commit
+cssHash=$(git log -n 1 --pretty=format:%h -- less/core.less)
+cssNewHash=$(git log -n 1 --pretty=format:%h -- less/new-core.less)
+cssPadHash=$(git log -n 1 --pretty=format:%h -- less/pad.less)
+
+echo "Adding write.css version ($cssHash $cssNewHash $cssPadHash) to .tmpl files..."
+cd "$buildDir/templates" || exit 1
+find . -type f -name "*.tmpl" -print0 | xargs -0 sed -i "s/write.css/write.css?${cssHash}${cssNewHash}${cssPadHash}/g"
+find . -type f -name "*.tmpl" -print0 | xargs -0 sed -i "s/{{.Theme}}.css/{{.Theme}}.css?${cssHash}${cssNewHash}${cssPadHash}/g"