Show the structure of a large nested hash - ruby

Question

I have a large hash which I'm trying to inspect, but because there are so many values it's hard to visually see what's going on.
For example say this is the hash:
{
days: {
monday: [1,2,3,4], # There are thousands of values here
tuesday: [1,2,3,4]
},
movies: {
action: ['Avengers', 'My Little Pony'],
adventure: ['Dorra The Explorer'],
comedy: ['Star Wars']
},
data_quality: 0.9,
verified: true
}
Now there is something going wrong and I need to examine what's going on here. It could be that I'm missing a movie category, a day of the week, or something in another field.
Because the Arrays are thousands of items long I can't just look at them to see what's missing.
Ideally I would like something like this:
{
days: {
monday: Array,
tuesday: Array
},
movies: {
action: Array,
adventure: Array,
comedy: Array
},
data_quality: Float,
verified: TrueClass
}
This would make the data a lot easier to analyse.
This is the method I'm currently using:
def hash_keys(hash)
unless hash.is_a?(Hash)
return hash.class
end
keys_hash = {}
hash.each do |key, value|
keys_hash[key] = hash_keys(value)
end
keys_hash
end
It's a recursive method which will run itself if the value is a hash, and return the values class otherwise.
The result for the sample input matches the expected output, however there is room for improvement. Like if all values in the Array are the same then show the value type (e.g. 'Array of ints') or if the array contains similar hashes, then what do those hashes look like?

Answer 1

I think #transform_values is perfect variant to help here:
def deep_values_transform(hash)
hash.transform_values do |value|
if value.is_a?(Hash)
deep_values_transform(value)
else
value.class
end
end
end
> hash = {
days: {
monday: [1,2,3,4],
tuesday: [1,2,3,4]
},
movies: {
action: ['Avengers', 'My Little Pony'],
adventure: ['Dorra The Explorer'],
comedy: ['Star Wars']
},
data_quality: 0.9,
verified: true
}
> deep_values_transform hash
=> {:days=>{:monday=>Array, :tuesday=>Array}, :movies=>{:action=>Array, :adventure=>Array, :comedy=>Array}, :data_quality=>Float, :verified=>TrueClass}