feat: Add Flipt provider gem with basic implementation

.github/workflows/ruby.yml

@@ -85,4 +85,26 @@ jobs:
           bundler-cache: true # runs 'bundle install' and caches installed gems automatically
           working-directory: ./providers/openfeature-go-feature-flag-provider
       - name: Lint and test
-        run: bin/rake
+        run: bin/rake
+
+  test_flipt_provider:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: ./providers/openfeature-flipt-provider
+    strategy:
+      matrix:
+        ruby-version:
+          - "3.3"
+          - "3.2"
+          - "3.1"
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby-version }}
+          bundler-cache: true # runs 'bundle install' and caches installed gems automatically
+          working-directory: ./providers/openfeature-flipt-provider
+      - name: Lint and test
+        run: bin/rake

providers/openfeature-flipt-provider/.gitignore

@@ -0,0 +1,11 @@
+/.bundle/
+/.yardoc
+/_yardoc/
+/coverage/
+/doc/
+/pkg/
+/spec/reports/
+/tmp/
+
+# rspec failure tracking
+.rspec_status

providers/openfeature-flipt-provider/.rspec

@@ -0,0 +1,4 @@
+-I lib
+--format documentation
+--color
+--require spec_helper

providers/openfeature-flipt-provider/.rubocop.yml

@@ -0,0 +1,5 @@
+inherit_from: ../../shared_config/.rubocop.yml
+
+inherit_mode:
+  merge:
+    - Exclude

providers/openfeature-flipt-provider/.ruby-version

@@ -0,0 +1 @@
+3.3.5

providers/openfeature-flipt-provider/Gemfile

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+source "https://rubygems.org"
+
+# Specify your gem's dependencies in openfeature-flipt-provider.gemspec
+gemspec

providers/openfeature-flipt-provider/Gemfile.lock

@@ -0,0 +1,108 @@
+PATH
+  remote: .
+  specs:
+    openfeature-flipt-provider (0.1.0)
+      ffi (~> 1.17)
+      flipt_client (~> 0.10.0)
+      openfeature-sdk (~> 0.4.0)
+
+GEM
+  remote: https://rubygems.org/
+  specs:
+    ast (2.4.3)
+    diff-lcs (1.6.1)
+    ffi (1.17.1)
+    ffi (1.17.1-aarch64-linux-gnu)
+    ffi (1.17.1-aarch64-linux-musl)
+    ffi (1.17.1-arm-linux-gnu)
+    ffi (1.17.1-arm-linux-musl)
+    ffi (1.17.1-arm64-darwin)
+    ffi (1.17.1-x86-linux-gnu)
+    ffi (1.17.1-x86-linux-musl)
+    ffi (1.17.1-x86_64-darwin)
+    ffi (1.17.1-x86_64-linux-gnu)
+    ffi (1.17.1-x86_64-linux-musl)
+    flipt_client (0.10.0)
+    json (2.10.2)
+    language_server-protocol (3.17.0.4)
+    lint_roller (1.1.0)
+    openfeature-sdk (0.4.0)
+    parallel (1.26.3)
+    parser (3.3.7.3)
+      ast (~> 2.4.1)
+      racc
+    prism (1.4.0)
+    racc (1.8.1)
+    rainbow (3.1.1)
+    rake (13.2.1)
+    regexp_parser (2.10.0)
+    rspec (3.12.0)
+      rspec-core (~> 3.12.0)
+      rspec-expectations (~> 3.12.0)
+      rspec-mocks (~> 3.12.0)
+    rspec-core (3.12.3)
+      rspec-support (~> 3.12.0)
+    rspec-expectations (3.12.4)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.12.0)
+    rspec-mocks (3.12.7)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.12.0)
+    rspec-support (3.12.2)
+    rubocop (1.73.2)
+      json (~> 2.3)
+      language_server-protocol (~> 3.17.0.2)
+      lint_roller (~> 1.1.0)
+      parallel (~> 1.10)
+      parser (>= 3.3.0.2)
+      rainbow (>= 2.2.2, < 4.0)
+      regexp_parser (>= 2.9.3, < 3.0)
+      rubocop-ast (>= 1.38.0, < 2.0)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (>= 2.4.0, < 4.0)
+    rubocop-ast (1.43.0)
+      parser (>= 3.3.7.2)
+      prism (~> 1.4)
+    rubocop-performance (1.24.0)
+      lint_roller (~> 1.1)
+      rubocop (>= 1.72.1, < 2.0)
+      rubocop-ast (>= 1.38.0, < 2.0)
+    ruby-progressbar (1.13.0)
+    standard (1.47.0)
+      language_server-protocol (~> 3.17.0.2)
+      lint_roller (~> 1.0)
+      rubocop (~> 1.73.0)
+      standard-custom (~> 1.0.0)
+      standard-performance (~> 1.7)
+    standard-custom (1.0.2)
+      lint_roller (~> 1.0)
+      rubocop (~> 1.50)
+    standard-performance (1.7.0)
+      lint_roller (~> 1.1)
+      rubocop-performance (~> 1.24.0)
+    unicode-display_width (3.1.4)
+      unicode-emoji (~> 4.0, >= 4.0.4)
+    unicode-emoji (4.0.4)
+
+PLATFORMS
+  aarch64-linux-gnu
+  aarch64-linux-musl
+  arm-linux-gnu
+  arm-linux-musl
+  arm64-darwin
+  ruby
+  x86-linux-gnu
+  x86-linux-musl
+  x86_64-darwin
+  x86_64-linux-gnu
+  x86_64-linux-musl
+
+DEPENDENCIES
+  openfeature-flipt-provider!
+  rake (~> 13.0)
+  rspec (~> 3.12.0)
+  rubocop
+  standard (>= 1.35.1)
+
+BUNDLED WITH
+   2.5.16

providers/openfeature-flipt-provider/README.md

@@ -0,0 +1,57 @@
+<p align="center">
+  <img width="400" src="https://raw.githubusercontent.com/flipt-io/flipt/main/logo.svg" alt="flipt logo" />
+</p>
+
+# Flipt - OpenFeature Ruby provider
+
+This repository contains the Ruby provider for [Flipt](https://www.flipt.io/), a feature flagging and experimentation platform.
+
+In conjunction with the [OpenFeature SDK](https://openfeature.dev/docs/reference/concepts/provider/) you can use this provider to integrate Flipt into your Ruby application.
+
+For documentation on how to use Flipt, please refer to the [Flipt documentation](https://docs.flipt.io/).
+
+## Installation
+Add this line to your application's Gemfile:
+
+```ruby
+gem 'openfeature-flipt-provider'
+```
+
+And then execute:
+```bash
+$ bundle
+```
+
+## Usage
+To use the Flipt provider, you need to create an instance of the provider and pass it to the OpenFeature SDK.
+
+```ruby
+require "open_feature/sdk"
+require "openfeature/flipt/provider"
+
+OpenFeature::SDK.configure do |config|
+  config.set_provider(
+    OpenFeature::Flipt::Provider.new(
+      namespace: "flipt-namespace",
+      options: {
+        url: "https://url-to-flipt-server",
+        update_interval: 60,
+        authentication: "token"
+      }
+    )
+  )
+end
+client = OpenFeature::SDK.build_client
+
+# Check if a feature is enabled
+if client.fetch_boolean_value(flag_key: "featureEnabled", default_value: false)
+  puts "Feature is enabled"
+else
+  puts "Feature is disabled"
+end
+```
+
+For a complete list of configuration options, such as authentication and error strategies, refer to the [Flipt Client Ruby SDK documentation](https://github.com/flipt-io/flipt-client-sdks/tree/main/flipt-client-ruby#constructor-arguments).
+
+## Contributing
+https://github.com/open-feature/ruby-sdk-contrib

providers/openfeature-flipt-provider/Rakefile

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+require "bundler/gem_tasks"
+require "rspec/core/rake_task"
+
+RSpec::Core::RakeTask.new(:spec)
+
+require "standard/rake"
+
+task default: %i[standard spec]

providers/openfeature-flipt-provider/bin/console

@@ -0,0 +1,11 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+require "bundler/setup"
+require "openfeature/flipt/provider"
+
+# You can add fixtures and/or initialization code here to make experimenting
+# with your gem easier. You can also use a different console, if you like.
+
+require "irb"
+IRB.start(__FILE__)

providers/openfeature-flipt-provider/bin/rake

@@ -0,0 +1,27 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+#
+# This file was generated by Bundler.
+#
+# The application 'rake' is installed as part of a gem, and
+# this file is here to facilitate running it.
+#
+
+ENV["BUNDLE_GEMFILE"] ||= File.expand_path("../Gemfile", __dir__)
+
+bundle_binstub = File.expand_path("bundle", __dir__)
+
+if File.file?(bundle_binstub)
+  if File.read(bundle_binstub, 300).include?("This file was generated by Bundler")
+    load(bundle_binstub)
+  else
+    abort("Your `bin/bundle` was not generated by Bundler, so this binstub cannot run.
+Replace `bin/bundle` by running `bundle binstubs bundler --force`, then run this command again.")
+  end
+end
+
+require "rubygems"
+require "bundler/setup"
+
+load Gem.bin_path("rake", "rake")

providers/openfeature-flipt-provider/bin/setup

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+set -euo pipefail
+IFS=$'\n\t'
+set -vx
+
+bundle install
+
+# Do any other automated setup that you need to do here