Fixes the case, when config_store is nil

Rakefile

@@ -2,7 +2,7 @@ require "bundler/gem_tasks"
 require "rake/testtask"
 require "rubocop/rake_task"
 
-Rake::TestTask.new(:test) do |t|
+Rake::TestTask.new(:rubocop_md_tests) do |t|
   t.libs << "test"
   t.libs << "lib"
   t.warning = false
@@ -11,4 +11,15 @@ end
 
 RuboCop::RakeTask.new
 
+task :test do
+  ENV["MD_LOAD_MODE"] = "inline"
+  $stdout.puts "⚙️ Runs rubocop with '-r rubocop_md' options"
+  Rake::Task[:rubocop_md_tests].invoke
+
+  ENV["MD_LOAD_MODE"] = "config"
+  $stdout.puts "⚙️ Runs rubocop with 'required rubocop_md' section in .rubocop.yml"
+  Rake::Task[:rubocop_md_tests].reenable
+  Rake::Task[:rubocop_md_tests].invoke
+end
+
 task default: [:rubocop, :test]

lib/rubocop/markdown/rubocop_ext.rb

@@ -42,9 +42,10 @@ def markdown_file?(file)
 
 RuboCop::Runner.prepend(Module.new do
   # Set config store for Markdown
-  def initialize(*args)
-    super
+  def get_processed_source(*args)
     RuboCop::Markdown.config_store = @config_store
+
+    super
   end
 
   # Do not cache markdown files, 'cause cache doesn't know about processing.

test/fixtures/.rubocop.yml

@@ -0,0 +1,5 @@
+inherit_from:
+  - "../../.rubocop.yml"
+
+require:
+  - "rubocop-md"

test/fixtures/configs/no_autodetect.yml

@@ -1,4 +1,4 @@
-inherit_from: "../../../.rubocop.yml"
+inherit_from: "../.rubocop.yml"
 
 Markdown:
   Autodetect: false

test/fixtures/configs/no_warn_invalid.yml

@@ -1,4 +1,5 @@
-inherit_from: "../../../.rubocop.yml"
+inherit_from: "../.rubocop.yml"
 
 Markdown:
   WarnInvalid: false
+

test/integration_test.rb

@@ -5,14 +5,31 @@
 require "fileutils"
 
 module RuboCopRunner
+  MD_LOAD_INLINE_MODE = "inline"
+
   def run_rubocop(path, options: "")
-    md_path = File.expand_path("../lib/rubocop-md.rb", __dir__)
     output, _status = Open3.capture2(
-      "bundle exec rubocop -r #{md_path} #{options} #{path}",
+      cmd_command_by_env(path, options),
       chdir: File.join(__dir__, "fixtures")
     )
+
     output
   end
+
+  private
+
+  def cmd_command_by_env(path, options)
+    cmd_command = "bundle exec rubocop"
+    load_mode = ENV.fetch("MD_LOAD_MODE", MD_LOAD_INLINE_MODE)
+
+    if load_mode == MD_LOAD_INLINE_MODE
+      md_path = File.expand_path("../lib/rubocop-md.rb", __dir__)
+
+      cmd_command = "#{cmd_command} -r #{md_path}"
+    end
+
+    "#{cmd_command} #{options} #{path}"
+  end
 end
 
 class RuboCop::Markdown::AnalyzeTest < Minitest::Test
@@ -26,6 +43,14 @@ def test_single_snippet_file
     assert_match %r{Style/StringLiterals}, res
   end
 
+  def test_file_with_format_options
+    res = run_rubocop("single_snippet.md", options: "--format progress")
+
+    assert_match %r{Inspecting 1 file}, res
+    assert_match %r{1 offense detected}, res
+    assert_match %r{Style/StringLiterals}, res
+  end
+
   def test_multiple_snippets_file
     res = run_rubocop("multiple_snippets.markdown")