Setup code coverage with simplecov

Rakefile

@@ -10,3 +10,13 @@ RSpec::Core::RakeTask.new(:spec)
 RuboCop::RakeTask.new
 
 task default: %i[spec rubocop]
+
+# Delete these files and folders when running rake clobber.
+CLOBBER.include('coverage', '.rspec_status')
+
+desc 'Run spec with coverage'
+task :coverage do
+  ENV['COVERAGE'] = 'true'
+  Rake::Task['spec'].execute
+  `open coverage/index.html`
+end

nostr.gemspec

@@ -44,4 +44,6 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'rubocop', '~> 1.42'
   spec.add_development_dependency 'rubocop-rake', '~> 0.6'
   spec.add_development_dependency 'rubocop-rspec', '2.16'
+  spec.add_development_dependency 'simplecov', '~> 0.22'
+  spec.add_development_dependency 'simplecov-console', '~> 0.9'
 end

spec/spec_helper.rb

@@ -2,6 +2,17 @@
 
 require 'nostr'
 require 'pry'
+require 'simplecov'
+require 'simplecov-console'
+
+SimpleCov.formatter = SimpleCov::Formatter::Console unless ENV['COVERAGE_FORMAT'] == 'html'
+
+unless ENV['COVERAGE'] == 'false'
+  SimpleCov.start do
+    root 'lib'
+    coverage_dir "#{Dir.pwd}/coverage"
+  end
+end
 
 RSpec.configure do |config|
   # Enable flags like --only-failures and --next-failure