added version check for isort

Summary: Added `isort` version check to ensure that produced formatting is compliant.

Reviewed By: ppwwyyxx

Differential Revision: D19421825

fbshipit-source-id: 51b8c113e09a1cc233f631f3cd4b1bdc485c4652

dev/linter.sh

@@ -3,13 +3,24 @@
 
 # Run this script at project root by "./dev/linter.sh" before you commit
 
+vergte() {
+  [ "$2" = "$(echo -e "$1\n$2" | sort -V | head -n1)" ]
+}
+
 {
 	black --version | grep "19.3b0" > /dev/null
 } || {
 	echo "Linter requires black==19.3b0 !"
 	exit 1
 }
 
+ISORT_TARGET_VERSION="4.3.21"
+ISORT_VERSION=$(isort -v | grep VERSION | awk '{print $2}')
+vergte "$ISORT_VERSION" "$ISORT_TARGET_VERSION" || {
+  echo "Linter requires isort>=${ISORT_TARGET_VERSION} !"
+  exit 1
+}
+
 set -v
 
 echo "Running isort ..."