Builtin function for setting a nested object key?

[caulagi]

Hi 👋 - How can I set a specific key for a nested object? For example, if I have -

base_test_input := {"resource_changes": [{
	"address": "google_compute_instance.default",
	"type": "google_compute_instance",
	"change": {
		"actions": ["create"],
		"after": {"metadata": {"foo": "bar"}},
	},
}]}

How can 'override' only the metadata portion to different values for different tests? I have tried object.union but it seems to require copying most of the rest of the object structure that I would like to avoid copying, if possible.

I was wondering if something like object.set or object.extent would make sense`

[anderseknert]

You could use the json.patch builtin function:

updated_meta := json.patch(base_test_input, [
	{"op": "replace", "path": "/resource_changes/0/change/after/metadata/foo", "value": "baz"}
])

[caulagi]

Thanks! I did look at json.patch but missed that I could index the array like you did.