How do I collect unique elements of an array-valued field across multiple objects in jq?

Question

I have json data that looks like:

{"foo":"one", "bar":2, "baz":[0]}
{"foo":"two", "bar":3, "baz":[1]}
{"foo":"one", "bar":3, "baz":[2,3]}
{"foo":"one", "bar":2, "baz":[2,4]}

I want to group everything with the same "foo" and collect the unique values of bar, and then collect the unique values inside of the "baz" arrays:

[
  {"foo":"one", "bar":[2, 3], "baz":[0,2,3,4]},
  {"foo":"two", "bar":[3], "baz":[1]}
]

(I don't care if the result is in an array or just a raw sequence of whitespace separated JSON objects, and I don't care about the order of the items in the "baz" array)

I've got jq version 1.4 installed from source. I can properly group by "foo" and collect unique values of "bar" with:

jq -s 'group_by(.foo) | map({foo: .[0].foo, bar: map(.bar) | unique})'

yielding:

[
  {"foo":"one","bar":[2,3]},
  {"foo":"two","bar":[3]}
]

but I can't figure out how to do the collection of unique values of "baz".

What am I missing?

Answer 1

Edit: new "flatten" function not needed (thanks @JeffMercado)

I can run

jq -s 'group_by(.foo) | map({foo: .[0].foo, bar: map(.bar) | unique, baz: map(.baz) | add | unique})

which produces:

[
  {"foo":"one","bar":[2,3],"baz":[0,2,3,4]},
  {"foo":"two","bar":[3],"baz":[1]}
]