Add the option stringify_keys to #as_json

[fabioperrella]

Hi folks! This is my 1st PR in this project.

If I did something wrong, please tell me!!

Motivation

fix #151

Proposal

• Add HashUtils.deep_transform_keys copied from the activesupport source code

I chose to not add activesupport as a dependency because it is good to have the least number of dependencies!

• Use HashUtils.deep_transform_keys to transform all the keys of the hash generated by as_json to a String

I chose to add the option stringify_keys on #as_json for backward compatibility. I also added info about it on README

[martijnvermaat]

The Travis tests fail because pry-byebug depends on Ruby 2.4. I suggest to separate the pry-byebug and example_status_persistence_file_path changes into separate PRs so they can be discussed and possibly merged independently.

[fabioperrella]

The Travis tests fail because pry-byebug depends on Ruby 2.4. I suggest to separate the pry-byebug and example_status_persistence_file_path changes into separate PRs so they can be discussed and possibly merged independently.

@martijnvermaat done! I will create another PR with these commits

[linkyndy]

Nice effort, Fabio! 🎉

Clean code, nice approach, concise tests. Keep it up!

[julik]

I would suggest making the expectations a bit less "smart". When dealing with tests it is usually a much more pleasant experience to be visually decoding the code under test, and not the test itself. In this instance the amount of functional sugar used occludes the fact that we want to verify that all keys we are scanning are kind_of(String). Can we use a more pedestrian each_pair (or alike) to the same effect?

[fabioperrella]

Sure, I agree the tests should be less "smart"!

Are you suggesting something like this?

result['entries'].each do |entry|
  entry.each do |key, value|
    expect(key).to be_a(String)
  end
end

I couldn't see a simpler way other than that.

[julik]

Yep that's perfect! If you opt for #each you might want to group the key-value using () though 😉

[fabioperrella]

From what I've seen, each_pair is an alias to each, isn't it?

you might want to group the key-value using () though

I didn't get it. Could you give me an example pls?

[julik]

Sure! I think some_hash.each do |(key, value)| is required instead of some_hash.each do |key, value| so that the array argument to the block is expanded into two variables. Or you can use each_pair instead

[fabioperrella]

cool! I didn't know about this parenthesis rule for block variables!

[fabioperrella]

Sorry for the long discussion about it, but I found interesting to know how it works and I think it's good to share it with you!

From what I saw, it is not necessary to use the () here. It would be necessary if the hash contained arrays as values and I wanted to access their values like this:

In this case, there are no arrays inside the hashes, and I just want to check their keys, so it makes no difference using ():

And also makes no difference using each or each_with_pair given they are aliases!

[fabioperrella]

tks @julik for all the comments!!

[julik]

🎩 My pleasure! Will approve once tests are green

[fabioperrella]

🎩 My pleasure! Will approve once tests are green

I messed up a test! Now that I fixed it, it will be green! :)