[gnome-shell-extensions] ci: Syntax-check js sources

[Florian Müllner <fmuellner src gnome org>]

commit fc8a46f15abec737becfa0798000d7805666db39
Author: Florian Müllner <fmuellner gnome org>
Date:   Sat Apr 11 00:22:06 2020 +0200

    ci: Syntax-check js sources
    
    This is currently done as part of `ninja test`, but doing the check
    in a separate CI job means it can run in parallel with other review
    jobs and fail before trying to build.
    
    https://gitlab.gnome.org/GNOME/gnome-shell-extensions/-/merge_requests/116

 .gitlab-ci.yml | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 2f14e2c..15af127 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,4 +1,4 @@
-image: registry.gitlab.gnome.org/gnome/gnome-shell/extension-ci:v1
+image: registry.gitlab.gnome.org/gnome/gnome-shell/extension-ci:v2
 
 stages:
  - review
@@ -6,6 +6,7 @@ stages:
 
 variables:
  LINT_LOG: "eslint-report.txt"
+ JS_LOG: "js-report.txt"
 
 .only_default: &only_default
     only:
@@ -21,6 +22,17 @@ check_commit_log:
     only:
         - merge_requests
 
+js_check:
+  stage: review
+  script:
+    - find extensions -name '*.js' -exec js68 -c -s '{}' ';' 2>&1 | tee $JS_LOG
+    - (! grep -q . $JS_LOG)
+  <<: *only_default
+  artifacts:
+    paths:
+      - ${JS_LOG}
+    when: on_failure
+
 eslint:
   stage: review
   script: