How I can delete key and value in array of hash? - ruby-on-rails

Question

I need delete all key created_at and updated_at in array of hashs . My hash looks like :
assessment_with_desc = {
"id": 1,
"name": "First assessment",
"created_at": "2020-03-14T20:13:27.006Z",
"updated_at": "2020-03-14T20:13:27.006Z",
"description_with_child_models": [
{
"id": 3,
"title": "First category",
"created_at": "2020-02-20T15:32:46.379Z",
"updated_at": "2020-03-14T20:16:11.530Z",
"accessment_id": 1,
"sub_categories": [
{
"id": 1,
"title": "First sub_category",
"category_id": 3,
"created_at": "2020-02-20T15:40:49.793Z",
"updated_at": "2020-02-20T15:40:49.793Z",
"stages": [
{
"id": 5,
"title": "First stage",
"sub_category_id": 1,
"created_at": "2020-02-20T15:44:10.603Z",
"updated_at": "2020-02-20T15:44:10.603Z"
}
]
}
]
}
]
}
I did it, but it work only in this case assessment_with_desc.delete('created_at') and assessment_with_desc.delete('updated_at'):
assessment_with_desc.delete('created_at')
assessment_with_desc.delete('updated_at')
assessment_with_desc['description_with_child_models'].delete('created_at')
assessment_with_desc['description_with_child_models'].delete('updated_at')
assessment_with_desc['description_with_child_models'][0]['sub_categories'].delete('created_at')
assessment_with_desc['description_with_child_models'][0]['sub_categories'].delete('updated_at')
assessment_with_desc['description_with_child_models'][0]['sub_categories'][0]['stages'].delete('created_at')
assessment_with_desc['description_with_child_models'][0]['sub_categories'][0]['stages'].delete('updated_at')

Answer 1

You can recursively invoke a function to remove the key/value in case the key is equal to :created_at or :updated_at:
def recursively_delete_timestamps(object)
object.transform_values do |value|
next value unless value.is_a?(Array)
value.map do |inner_hash|
recursively_delete_timestamps(inner_hash)
end
end.reject do |key, _|
key.in?(%i[created_at updated_at])
end
end
recursively_delete_timestamps(assessment_with_desc)
# {:id=>1,
# :name=>"First assessment",
# :description_with_child_models=>
# [{:id=>3,
# :title=>"First category",
# :accessment_id=>1,
# :sub_categories=>
# [{:id=>1,
# :title=>"First sub_category",
# :category_id=>3,
# :stages=>[{:id=>5, :title=>"First stage", :sub_category_id=>1}]}]}]}
Notice, the hash remains unchanged. Nor transform_values, map or reject modify the original object, but return a new one.