test: Start a spec to exercise the code in the README (#40)

Author: technicalpickles

Gemfile.lock

@@ -10,6 +10,7 @@ GEM
     concurrent-ruby (1.2.2)
     diff-lcs (1.5.0)
     json (2.6.2)
+    markly (0.7.0)
     parallel (1.22.1)
     parser (3.1.2.1)
       ast (~> 2.4.1)
@@ -57,6 +58,7 @@ PLATFORMS
 
 DEPENDENCIES
   concurrent-ruby
+  markly
   openfeature-sdk!
   rake (~> 13.0)
   rspec (~> 3.12.0)

openfeature-sdk.gemspec

@@ -31,6 +31,7 @@ Gem::Specification.new do |spec|
   spec.executables = spec.files.grep(%r{\Aexe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
+  spec.add_development_dependency "markly"
   spec.add_development_dependency "rake", "~> 13.0"
   spec.add_development_dependency "rspec", "~> 3.12.0"
   spec.add_development_dependency "rubocop", "~> 1.37.1"

spec/openfeature/example_spec.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+RSpec.describe "README example" do
+  before do
+    @readme_md = Pathname.new("../../../README.md").expand_path(__FILE__)
+
+    doc = Markly.parse(@readme_md.read)
+    doc.walk do |node|
+      if node.type == :code_block && node.fence_info == "ruby"
+        @example_codeblock = node
+        break
+      end
+    end
+  end
+
+  it "works" do
+    expect do
+      eval @example_codeblock.string_content, # rubocop:disable Security/Eval
+           binding,
+           @readme_md.to_s,
+           @example_codeblock.source_position[:start_line] + 1
+    end.not_to raise_error
+  end
+end

spec/spec_helper.rb

@@ -2,6 +2,8 @@
 
 require "openfeature/sdk"
 
+require "markly"
+
 RSpec.configure do |config|
   # Enable flags like --only-failures and --next-failure
   config.example_status_persistence_file_path = ".rspec_status"