Add top level mapping element when converting a json file to yaml

Question

I have the following json file:

{
  "test1": {
      "POST": "{}",
      "GET": "{}"
  },
  "test2": {
      "HEAD": "{}",
      "GET": "{}"
  }
}

I can convert it to yaml as follows:

yq eval -P input.json --output-format=yaml 

which gives me:

test1:
  POST: '{}'
  GET: '{}'
test2:
  HEAD: '{}'
  GET: '{}'

Is there an elegant (yq - based way) of:

a) adding a top level mapping element (say named config) as in

config:
  test1:
    POST: '{}'
    GET: '{}'
  test2:
    HEAD: '{}'
    GET: '{}'

b) removing the single quotes from '{}'?

I want my end result to be

config:
  test1:
    POST: {}
    GET: {}
  test2:
    HEAD: {}
    GET: {}

Thanks!

Answer 1

Add a filter to your yq invocation.

• {"config": .} adds a wrapping field
• .[][] |= fromjson interprets any value two levels deep as JSON-encoded string.

Put together:

yq eval -P '{"config": (.[][] |= fromjson)}' input.json --output-format=yaml

config:
  test1:
    POST: {}
    GET: {}
  test2:
    HEAD: {}
    GET: {}

Tested with mikefarah/yq v4.35.1

Note: Since v4.18.1, the eval/e command is the default, and can be omitted.