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Json – How to assign field name in jq based on a try catch?

I have a JSON object, some keys of which have names end in .json, like this:

{
    "a.json": "...",
    ....
}

The "..." can be either a string which fromjson can decode, or something else.

I want a jq filter which will, in the first case, replace the key’s value by its fromjson equivalent, e.g. "{}" would become {}, resulting in:

{
    "a.json": {},
   ....
}

Otherwise, the .json suffix should be removed from the key, so that if for example the value was "shh" the net result would be:

{
    "a": "shh",
    ....
}

All keys ending with .json (like the a.json above) should be processed in this way. Any other key-value pairs should be left unaltered.

When:

with_entries(
        select(.key|test(".json$")) as $root
            | $root.value = $root.value as $sub | ($sub|try fromjson catch $sub)
)

This works for the value, but I cannot find a way to chnge the .key in the catch block.

Tags:

2

Answers


  1. 0

    You can use the error supression operator ? in combination with the alternative operator //:

    with_entries(
  select(.key | endswith(".json")) |= (.value |= fromjson)? // .key |= rtrimstr(".json")
)

    Demo

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  2. 0

    It’s not pretty but this does what you’re asking

    # {
#   "a.json": "{"x":42}",
#   "b.json": "false",
#   "c.json": "no JSON value",
#   "d": "key mismatch"
# }

jq '
to_entries
| map( .value as $v | .key as $k
  | if (.key|test("json")) 
    then ( try {key,value: (.value|fromjson)} catch {key:($k|gsub(".json";"")),value:$v} )  
    else . end
  )
| from_entries'

    Output:

    {
  "a.json": {
    "x": 42
  },
  "b.json": false,
  "c": "no JSON value",
  "d": "key mismatch"
}
    Login or Signup to reply.
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