Add test to ensure recommended setup works

Author: khiga8

.erb-lint.yml

@@ -0,0 +1,4 @@
+---
+inherit_gem:
+  erblint-github:
+    - config/accessibility.yml

.erb-linters/linters.rb

@@ -0,0 +1 @@
+require "erblint-github/linters"

test/linter_test_case.rb

@@ -5,9 +5,7 @@ def setup
     @linter = linter_class&.new(file_loader, linter_class.config_schema.new)
   end
 
-  def linter_class
-    raise NotImplementedError
-  end
+  def linter_class; end
 
   def offenses
     @linter.offenses

test/recommended_setup_works_test.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+class RecommendedSetupWorksTest < LinterTestCase
+  # The ability to share rules and configs from other gems in erb_lint is not well-documented.
+  # This test validates that our recommended setup works.
+  def test_asserts_recommended_setup_works
+    erb_lint_config = ERBLint::RunnerConfig.new(file_loader.yaml(".erb-lint.yml"), file_loader)
+
+    rules_enabled_in_accessibility_config = 0
+    erb_lint_config.to_hash["linters"].each do |linter|
+      if linter[0].include?("GitHub::Accessibility") && linter[1]["enabled"] == true
+        rules_enabled_in_accessibility_config += 1
+      end
+    end
+    known_linter_names ||= ERBLint::LinterRegistry.linters.map(&:simple_name)
+
+    assert_equal 15, rules_enabled_in_accessibility_config
+    assert_equal 15, known_linter_names.count { |linter| linter.include?("GitHub::Accessibility") }
+  end
+end