Handle nil paths in json_printer's sort_by (#561)

Fix #560

Author: charlespwd

lib/theme_check/json_printer.rb

@@ -25,7 +25,7 @@ def offenses_by_path(offenses)
             styleCount: path_offenses.count { |offense| offense[:severity] == Check::SEVERITY_VALUES[:style] },
           }
         end
-        .sort_by { |o| o[:path] }
+        .sort_by { |o| o[:path] || Pathname.new('') }
     end
   end
 end

test/cli_test.rb

@@ -25,13 +25,20 @@ def test_check_format_json
         {% assign x = 1 %}
         {% assign y = 2 %}
       LIQUID
+      "config/placeholder" => '',
+      "assets/placeholder" => '',
+      "locales/placeholder" => '',
+      "snippets/example.liquid" => '',
       "templates/example.liquid" => <<~LIQUID,
         {% assign z = 1 %}
       LIQUID
       ".theme-check.yml" => <<~YAML,
         extends: :nothing
         UnusedAssign:
           enabled: true
+        RequiredDirectories:
+          enabled: true
+          severity: suggestion
       YAML
     )
 
@@ -41,6 +48,23 @@ def test_check_format_json
 
     assert_equal(
       JSON.dump([
+        {
+          "path" => nil,
+          "offenses" => [
+            {
+              "check" => "RequiredDirectories",
+              "severity" => 1,
+              "start_row" => 0,
+              "start_column" => 0,
+              "end_row" => 0,
+              "end_column" => 0,
+              "message" => "Theme is missing 'sections' directory",
+            },
+          ],
+          "errorCount" => 0,
+          "suggestionCount" => 1,
+          "styleCount" => 0,
+        },
         {
           "path" => "layout/theme.liquid",
           "offenses" => [