Replace tests with specs

Gemfile

@@ -2,7 +2,7 @@ source 'https://rubygems.org'
 
 gemspec
 
-gem 'minitest'
-gem 'rake'
 gem 'coveralls', require: false
+gem 'rake'
+gem 'rspec'
 gem 'rubocop'

Rakefile

@@ -1,16 +1,16 @@
 # encoding: utf-8
 
-require 'rake/testtask'
 require 'rubocop/rake_task'
+require 'rspec/core/rake_task'
 
-Rake::TestTask.new do |t|
-  t.libs = %w( lib test )
-  t.test_files = FileList['test/**/test_*.rb', 'test/**/*_spec.rb']
+RSpec::Core::RakeTask.new(:spec) do |t|
+  t.rspec_opts = '-r ./spec/spec_helper.rb --color'
+  t.verbose = false
 end
 
 RuboCop::RakeTask.new(:rubocop) do |task|
   task.options  = %w( --display-cop-names --format simple )
   task.patterns = ['lib/**/*.rb', 'test/**/*.rb']
 end
 
-task :default => [:test, :rubocop]
+task :default => [:spec, :rubocop]

spec/filter_spec.rb

@@ -0,0 +1,7 @@
+describe Nanoc::Asciidoctor::Filter do
+  let(:filter) { described_class.new }
+
+  subject { filter.setup_and_run('== Blah blah') }
+
+  it { is_expected.to match(%r{<h2 id="_blah_blah">Blah blah</h2>}) }
+end

test/helper.rb → spec/spec_helper.rb

@@ -1,7 +1,5 @@
 require 'coveralls'
 Coveralls.wear!
 
-require 'minitest'
-require 'minitest/autorun'
 require 'nanoc'
 require 'nanoc-asciidoctor'