jq deep merge

gistfile1.txt

➜  ~  cat a.json
{
    "_meta": {
        "tag_environment_magic": [
            "a"
        ]
    }
}
➜  ~  cat b.json
{
    "_meta": {
        "tag_environment_magic": [
            "b"
        ]
    }
}
➜  ~  jq -s 'reduce .[] as $x ({}; . * $x)' a.json b.json
{
  "_meta": {
    "tag_environment_magic": [
      "b"
    ]
  }
}


Expected:
{
  "_meta": {
    "tag_environment_magic": [
      "a",
      "b"
    ]
  }
}

see https://stackoverflow.com/a/53666584/200509 for something that, in the end, kinda worked for me 😅