Add tests scripts
diff --git a/tests/tests.sh b/tests/tests.sh
new file mode 100644
index 0000000..29b31f7
--- /dev/null
+++ b/tests/tests.sh
@@ -0,0 +1,53 @@
+#!/bin/bash
+
+base="$(dirname "$(readlink -f -- $0)")/.."
+cd $base
+
+#Keep knownKeys
+rm -f tests/priorities
+touch tests/priorities tests/knownKeys
+result=0
+find -name AndroidManifest.xml |while read manifest;do
+	folder="$(dirname "$manifest")"
+	#Ensure this overlay doesn't override blacklist-ed properties
+	for b in $(cat tests/blacklist);do
+		if grep -qRF "$b" $folder;then
+			echo "Overlay $folder is defining $b which is forbidden"
+			result=1
+		fi
+	done
+
+	#Everything after that is specifically for static overlays, targetting framework-res
+	isStatic="$(xmlstarlet sel -t -m '//overlay' -v @android:isStatic -n $manifest)"
+	[ "$isStatic" != "true" ] && continue
+
+	#Ensure priorities unique-ness
+	priority="$(xmlstarlet sel -t -m '//overlay' -v @android:priority -n $manifest)"
+	if grep -qE '^'$priority'$' tests/priorities;then
+		echo $manifest priority $priority conflicts with another manifest
+		result=1
+	fi
+	echo $priority >> tests/priorities
+
+	systemPropertyName="$(xmlstarlet sel -t -m '//overlay' -v @android:requiredSystemPropertyName -n $manifest)"
+	if [ "$systemPropertyName" == "ro.vendor.product.name" ];then
+		echo "$manifest: ro.vendor.product.name is deprecated. Please use ro.vendor.build.fingerprint"
+	fi
+
+	#Ensure the overloaded properties exist in AOSP
+	find "$folder" -name \*.xml |while read xml;do
+		keys="$(xmlstarlet sel -t -m '//resources/*' -v @name -n $xml)"
+
+		for key in $keys;do
+			grep -q $key tests/knownKeys && continue
+			if ag '"'$key'"' /build/AOSP-9.0/frameworks/base/core/res/res > /dev/null;then
+				echo $key >> tests/knownKeys
+			else
+				echo $xml defines a non-existing attribute $key
+			fi
+		done
+	done
+done
+rm -f tests/priorities
+
+exit $result