add disable rule test

Author: khiga8

lib/erblint-github/linters/custom_helpers.rb

@@ -11,7 +11,7 @@ def rule_disabled?(processed_source)
           indicator_node, _, code_node, = *node
           indicator = indicator_node&.loc&.source
           comment = code_node&.loc&.source&.strip
-          rule_name = self.class.name.match(/:?:?(\w+)\Z/)[1]
+          rule_name = self.class.name.gsub("ERBLint::Linters::", "")
 
           if indicator == "#" && comment.start_with?("erblint:disable") && comment.match(rule_name)
             if @offenses.any?

test/linters/accessibility/no_redundant_image_alt_test.rb

@@ -28,4 +28,14 @@ def test_does_not_warn_if_alt_contains_no_redundant_text
 
     assert_empty @linter.offenses
   end
+
+  def test_does_not_warn_if_linter_is_disabled_in_file
+    @file = <<~HTML
+      <%# erblint:disable GitHub::Accessibility::NoRedundantImageAlt %>
+      <img alt='image of an octopus'></img>
+    HTML
+
+    @linter.run(processed_source)
+    assert_empty @linter.offenses
+  end
 end