[gnome-shell] ci: Ensure eslint output exists

[Florian Müllner <fmuellner src gnome org>]

commit caa50dc1a3e6a3772318f892c011821f0f89ad79
Author: Florian Müllner <fmuellner gnome org>
Date:   Wed Aug 14 13:14:23 2019 +0200

    ci: Ensure eslint output exists
    
    We are a long time away from an error-free eslint run,
    but when we get there eventually, let's not trip over
    non-existent files ...
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/730

 .gitlab-ci/run-eslint.sh | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
---
diff --git a/.gitlab-ci/run-eslint.sh b/.gitlab-ci/run-eslint.sh
index ae4aee979f..edcdfc1fd8 100755
--- a/.gitlab-ci/run-eslint.sh
+++ b/.gitlab-ci/run-eslint.sh
@@ -16,8 +16,14 @@ run_eslint() {
   ARGS_LEGACY='--config lint/eslintrc-legacy.json'
 
   local extra_args=ARGS_$1
-  local output=OUTPUT_$1
-  eslint -f unix ${!extra_args} -o ${!output} js
+  local output_var=OUTPUT_$1
+  local output=${!output_var}
+
+  # ensure output exists even if eslint doesn't report any errors
+  mkdir -p $(dirname $output)
+  touch $output
+
+  eslint -f unix ${!extra_args} -o $output js
 }
 
 list_commit_range_additions() {