Closing the JSON properly in Ansible (replace last comma with curly braces)

replace.yml

# Sometimes there are moments, when you construct JSON in a really dirty way by just appending key/value pairs and adding comma at the end.
# You will end up with something like this:

# {
#   "big_key": {
#     "small_key1": "small_value1",
#     "small_key2": "small_value2",
#     "small_key3": "small_value3",

# And then to make this valid JSON, you need to replace the last comma with curly braces.
# This is an example how to do it in Ansible using regex in the replace module:

- name: Fix the broken JSON
  replace:
    path: "unfinished.json"
    regexp: ',.*$\n\Z'
    replace: '\n  } \n}'