tests: add a test to prove cron:run commands work as expected

Closes #8242

tests/unit/builder-pack.bats

@@ -143,3 +143,45 @@ teardown() {
   assert_success
   assert_output_contains '"APP_RESPECTS_ENV_VARS": "1"'
 }
+
+@test "(builder-pack) cron:run" {
+  run /bin/bash -c "dokku config:set $TEST_APP SECRET_KEY=fjdkslafjdk"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+
+  run /bin/bash -c "dokku builder:set $TEST_APP selected pack"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+
+  run deploy_app python dokku@$DOKKU_DOMAIN:$TEST_APP cron_run_wrapper
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+  assert_output_contains 'from cnb stack'
+  assert_output_contains 'Building with buildpack 1' 0
+  assert_output_contains 'Installing dependencies using pip'
+
+  cron_id="$(dokku cron:list $TEST_APP --format json | jq -r '.[0].id')"
+  run /bin/bash -c "echo $cron_id"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+  assert_output_exists
+
+  run /bin/bash -c "dokku cron:run $TEST_APP $cron_id"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+  assert_output "['task.py', 'some', 'cron', 'task']"
+}
+
+cron_run_wrapper() {
+  local APP="$1"
+  local APP_REPO_DIR="$2"
+  [[ -z "$APP" ]] && local APP="$TEST_APP"
+
+  add_requirements_txt "$APP" "$APP_REPO_DIR"
+  mv -f "$APP_REPO_DIR/app-cron-cnb.json" "$APP_REPO_DIR/app.json"
+}