Add a custom inspect string for StaticFile objects (#7422)

Merge pull request 7422

lib/jekyll/static_file.rb

@@ -152,6 +152,12 @@ module Jekyll
       @defaults ||= @site.frontmatter_defaults.all url, type
     end
 
+    # Returns a debug string on inspecting the static file.
+    # Includes only the relative path of the object.
+    def inspect
+      "#<#{self.class} @relative_path=#{relative_path.inspect}>"
+    end
+
     private
 
     def copy_file(dest_path)

test/test_static_file.rb

@@ -48,6 +48,11 @@ class TestStaticFile < JekyllUnitTest
       remove_dummy_file(@filename) if File.exist?(source_dir(@filename))
     end
 
+    should "return a simple string on inspection" do
+      static_file = setup_static_file("root", "dir", @filename)
+      assert_equal "#<Jekyll::StaticFile @relative_path=\"dir/#{@filename}\">", static_file.inspect
+    end
+
     should "have a source file path" do
       static_file = setup_static_file("root", "dir", @filename)
       assert_equal "root/dir/#{@filename}", static_file.path