a bit o' spruce, from http://play.spruce.cf

spruce.json

{"flavor":"1.16.1","prune":[],"env":["HOME=/home/user"],"cherry_pick":[],"yaml":[{"filename":"fileA.yml","contents":"--- # fileA.yml\nlist:\n- name: one\n  params:\n    preload: true\n    fail-fast: false\n\n- name: two\n  params:\n    preload: true\n    fail-fast: false\n\n"},{"filename":"fileB.yml","contents":"--- # fileB.yml\nlist:\n- name: two\n  params:\n    preload: false\n    fail-fast: (( prune ))\n\n- (( prepend ))\n- name: zero\n  params:\n    preload: true\n    fail-fast: false\n\n"}],"skip_eval":false,"fallback_append":false,"go_patch":false,"debug":true,"trace":false}