Change how we handle file change detection for pa11y

.circleci/config.yml

@@ -47,23 +47,34 @@ jobs:
  # that we can make pa11y-ci scan only those changed files
  # in the "Run pa11y scan on changed files" step if it's
  # needed, a full site scan does not use the pa11y_targets file
+ # If this pipeline run is triggered from a GitHub PR commit webhook
+ # we check for the pa11y_targets file
+ # - if the file exists it means Jekyll found changed files and we will scan that list
+ # - if the file does not exist it means Jekyll didn't detect any changed files and we skip the pa11y scan
+ # If this pipeline run is triggered by a schedule that's our nightly full pa11y scan
+ # which doesn't need to interact with PA11Y_TARGETS since it runs off the sitemap to do a fulll scan
  command: |
  bundle exec jekyll build
- if test -f pa11y_targets; then
- echo "export PA11Y_TARGETS=$(cat pa11y_targets | base64 --wrap=0)" >> "$BASH_ENV"
- export DO_PA11Y_SCAN=true >> "$BASH_ENV"
- echo "Changed files detected, pa11y scan will be performed on those files."
- else
- export DO_PA11Y_SCAN=false >> "$BASH_ENV"
- echo "No changed files detected, pa11y scan will be skipped."
+ if [[ << pipeline.trigger_source >> == "webhook" ]]; then
+ if test -f pa11y_targets; then
+ echo "export PA11Y_TARGETS=$(cat pa11y_targets | base64 --wrap=0)" >> "$BASH_ENV"
+ export DO_PA11Y_SCAN=true >> "$BASH_ENV"
+ echo "Changed files detected, pa11y scan will be performed on those files."
+ else
+ export DO_PA11Y_SCAN=false >> "$BASH_ENV"
+ echo "No changed files detected, pa11y scan will be skipped."
+ fi
+ source "$BASH_ENV"
+ fi
+ 
+ if [[ << pipeline.trigger_source >> == "schedule" ]]; then
+ echo "Scheduled workflow detected, full pa11y scan will be performed."
  fi
- source "$BASH_ENV"
  - run: npm run htmlproofer
  - run:
  name: Run rspec
  command: bundle exec rspec `pwd`/spec/
- # The nightly full pa11y scan is triggered from a scheduled pipeline
- # which satisfies this condition
+ # The nightly full pa11y scan is triggered from a scheduled pipeline which satisfies this condition
  - when:
  condition:
  equal: [ schedule, << pipeline.trigger_source >> ]
@@ -88,7 +99,7 @@ workflows:
  triggers:
  - schedule:
  # Run nightly at 10am UTC / 5am ET
- cron: "25 * * * *"
+ cron: "15 * * * *"
  filters:
  branches:
  only: