Append new element to JSON object in specific format using bash and jq - json

Question

I would like to append an element to an existing JSON file where I have the working directory as the key and the working directory + the contents as the value in a string array format.
Lets say I have the following structure:
Docs (Directory)
|
+-- RandomFile.json
|
+-- Readme (Working Directory)
| |
| +-- Readme.md
| +-- Readyou.md
What I would like to achieve is the structure below with the working directory as the prefix for every element in the array.
"Readme": ["Readme/Readme.md", "Readme/Readyou.md"]
From the output above, I would like to append that to the contents of the RandomFile.json which currently looks like this:
{
"docs": {
"Doc": ["doc1"]
}
}
to this:
{
"docs": {
"Doc": ["doc1"],
"Readme": ["Readme/Readme.md", "Readme/Readyou.md"]
}
}
Is it something that can be managed straightforward using bash and jq?

Answer 1

This requires jq 1.6 in order to use the --args option.
$ jq --arg wd "$(basename "$PWD")" '.docs+={($wd): $ARGS.positional | map("\($wd)/\(.)")}' ../RandomFile.json --args *
{
"docs": {
"Doc": [
"doc1"
],
"Readme": [
"Readme/Readme.md",
"Readme/Readyou.md"
]
}
}
The shell is used to pass the base name of the current working directory as the variable $wd.
The shell is also used to pass the names of all the files in the current working directory as separate arguments.
The file to edit is assumed to be ../RandomFile.json; if you only know that there is a JSON file in the parent, you can use ../*.json instead.
Use += to update the .docs object of the original with a new key (the working directory) and list of file names. map prefixes each element of $ARGS.positional with $wd.