Reference parent key name when replacing value of sub-key

[manuelgrabowski]

I have the following input:

toplevel1:
  replaceme: "test1"
  keepme1: "test2"
  keepme2:
    - "test3"
    - "test4"

toplevel2:
  replaceme: "test5"
  keepme2:
    - "test6"
    - "test7"


toplevel3:
  replaceme:
    - "test8"
    - "test9"
  keepme1: "test0"

and want to get to this output:

toplevel1:
  replaceme: "foobar in toplevel1"
  keepme1: "test2"
  keepme2:
    - "test3"
    - "test4"

toplevel2:
  replaceme: "foobar in toplevel2"
  keepme2:
    - "test6"
    - "test7"


toplevel3:
  replaceme: "foobar in toplevel3"
  keepme1: "test0"

So replace the replaceme elements, regardless of them being a string or an array, with a string that contains the parent key name. I got the replacing part: yq '. | (.[].replaceme |= "foobar in ")'

But I can't figure out how back-reference to the toplevel key names in the value assignment.

[mikefarah]

You can use the parent operator to access the parent map, then key to get the key value:

yq '(.. | select(has("replaceme")) | .replaceme) |= ("foobar in " + (parent | key))' file.yaml

Note that I also have .. | select(has("replaceme")) | .replaceme:

• .. recursively matches all the nodes
• select(has("replaceme")) will select all the nodes that have that field defined

Edit: formatting

[mikefarah]

toplevel1:
  replaceme: "foobar in toplevel1"
  keepme1: "test2"
  keepme2:
    - "test3"
    - "test4"
toplevel2:
  replaceme: "foobar in toplevel2"
  keepme2:
    - "test6"
    - "test7"
toplevel3:
  replaceme: foobar in toplevel3
  keepme1: "test0"

[manuelgrabowski]

Once again, thank you very much for the detailed explanation! 🙏