feat: new GO Feature Flag ruby provider

[thomaspoignant]

This PR

• This PR contains the implementation of a ruby provider for GO Feature Flag.

[alxckn]

Looks pretty complete overall :)

[maxveldink]

I don't see any real blockers to merging this in an releasing a 0.1.0 with this. I found it hard to believe this was your first real go at Ruby @thomaspoignant!

A few things:

• I would be interested in chopping this PR up a little bit more and merging in some smaller chunks that I could provide more in-depth feedback on: at least maybe starting with a scaffolding PR for the new gem structure, and separate PRs for implementing the Ruby-focused interaction with GO Feature Flag and the actual Provider wire up
• I think there are some extractable pieces here around generalizing an OFREP-compliant HTTP client that we could easily reuse in other providers that I'm interested in iterating on in the future
• I did not have too much time tor really dig into spec feedback or provide as many Ruby notes on the Provider itself; if we do end up chopping this into multiple PRs, I can provide more detailed feedback there.

[maxveldink]

suggestion(non-blocking): These are great specs for your first use of RSpec! Completely optional, but a handy paradigm to get into in RSpec is to use the context blocks as scopes where you're altering the test world based on the conditionals in your test names. For example, we could write this test to highlight that the endpoint variable is changing, utilizing contexts.

Suggested change

	context "#endpoint" do
	it "should have a valid endpoint set" do
	options = OpenFeature::GoFeatureFlag::Options.new(endpoint: "http://localhost:1031")
	expect(options.endpoint).to eql("http://localhost:1031")
	end
	it "should raise if endpoint is invalid" do
	expect { OpenFeature::GoFeatureFlag::Options.new(endpoint: "invalid_url") }.to raise_error(ArgumentError, "Invalid URL for endpoint: invalid_url")
	end
	it "should raise if endpoint is not http" do
	expect { OpenFeature::GoFeatureFlag::Options.new(endpoint: "ftp://gofeatureflag.org") }.to raise_error(ArgumentError, "Invalid URL for endpoint: ftp://gofeatureflag.org")
	end
	end
	describe "#endpoint" do
	subject(:options) { described_class.new(endpoint:) }
	context "when endpoint is valid" do
	let(:endpoint) { "http://localhost:1031" }
	it "sets endpoint" do
	expect(options.endpoint).to eq(endpoint)
	end
	end
	context "when endpoint is invalid" do
	let(:endpoint) { "invalid_url" }
	it "raises ArgumentError" do
	expect { options }.to raise_error(ArgumentError, "Invalid URL for endpoint: invalid_url")
	end
	end
	context "when endpoint is non-http" do
	let(:endpoint) { "ftp://gofeatureflag.org" }
	it "raises ArgumentError" do
	expect { options }.to raise_error(ArgumentError, "Invalid URL for endpoint: ftp://gofeatureflag.org")
	end
	end
	end

I'll avoid giving the same advice on the other tests, and I'll approve as is, but just some food for thought!

[thomaspoignant]

interesting I will keep it in mind when writing new tests.

[thomaspoignant]

@maxveldink thanks a lot for your review.

I am not sure I will have the time to split this PR in multiple smaller ones (I am on vacation starting this week and I would like to merge it).

As discussed this 1st implementation could be a good base for an OFREP provider.
In the fixes I have addressed most of your comments.

The biggest one is that I now use faraday as HTTP Client, which avoids a lot of boilerplate when it comes to configuring the HTTP connection,

[thomaspoignant]

interesting I will keep it in mind when writing new tests.