Remove duplicates from JSON arrays

I want to remove the duplicates from each array in this JSON:

{
  "abc": [
    "five"
  ],
  "pqr": [
    "one",
    "one",
    "two",
    "two",
    "three",
    "three",
    "four",
    "four"
  ],
  "xyz": [
    "one",
    "one",
    "two",
    "two",
    "four"
  ]
}

Output I am expecting after removing the duplicates:

{
  "abc": [
    "five"
  ],
  "pqr": [
    "one",
    "two",
    "three",
    "four"
  ],
  "xyz": [
    "one",
    "two",
    "four"
  ]
}

I tried map, uniq, group_by with jq but nothing helped

unique can remove duplicates, but it automatically sorts the arrays, which may or may not be what you want.

jq '.[] |= unique'

{
  "abc": [
    "five"
  ],
  "pqr": [
    "four",
    "one",
    "three",
    "two"
  ],
  "xyz": [
    "four",
    "one",
    "two"
  ]
}

Demo

You can retrieve the original ordering by recreating the array based on sort ing the index positions of all of its unique items:

jq '.[] |= [.[[index(unique[])] | sort[]]]'

Demo

Or circumvent any sorting behaviour by writing your own straightforward de-duplication function:

jq '.[] |= reduce .[] as $i ([]; . + if index($i) then [] else [$i] end)'

Demo

In my tests, the latter performed best, with both producing

{
  "abc": [
    "five"
  ],
  "pqr": [
    "one",
    "two",
    "three",
    "four"
  ],
  "xyz": [
    "one",
    "two",
    "four"
  ]
}