For perf-frontend-issues#211: add pycodestyle to pre-push hook.

config/pre-push-recommended.sh

@@ -11,10 +11,21 @@
 # You can use it by running this command from the project root:
 # `ln -s ../../config/pre-push-recommended.sh .git/hooks/pre-push`
 
-# Descriptions for each gradle task below can be found in the
-# output of `./gradlew tasks`.
+set -e
 
-# Run core checks.
+# Run linter in tools/ if it's installed.
+if `which pycodestyle > /dev/null`; then
+    pycodestyle tools
+fi
+
+# Run core checks. Descriptions for each gradle task
+# below can be found in the output of `./gradlew tasks`.
+#
+# Tasks omitted because they take a long time to run:
+# - assembling all variants
+# - unit test on all variants
+# - UI tests
+# - android lint (takes a long time to run)
 ./gradlew -q \
         ktlint \
         detekt \
@@ -23,9 +34,3 @@
         mozilla-detekt-rules:test \
         mozilla-lint-rules:test \
         testDebug
-
-# Tasks omitted because they take a long time to run:
-# - assembling all variants
-# - unit test on all variants
-# - UI tests
-# - android lint (takes a long time to run)