WEB-6543: Updating linter file existence checker to work with subfiles

Paths in markdown metadata should always be relative to the markdown
file itself. This updates the file existence checker so that that is
the case.

app/lib/linting/metadata/captions_file.rb

@@ -40,13 +40,16 @@ def video_course_captions
       def module_captions
         caption_files = ModuleFile.new(file:, attributes:).file_path_list
         caption_files.map do |file|
-          if yaml?(file)
+          captions_file = if yaml?(file)
             load_yaml(File.read(file)).deep_symbolize_keys[:captions_file]
           else
             @markdown_metadata = nil
             @path = file
             markdown_metadata[:captions_file]
           end
+          next unless captions_file.present?
+
+          [captions_file, file]
         end.compact
       end
 

app/lib/linting/metadata/file_attribute_existence_checker.rb

@@ -8,15 +8,21 @@ module FileAttributeExistenceChecker
 
       def file_attribute_annotations
         file_path_list.map do |path|
-          next if relative_file_exists?(path)
+          if path.is_a?(Array)
+            relative_to = path.second
+            path = path.first
+          else
+            relative_to = file
+          end
+          next if relative_file_exists?(path, relative_to:)
 
           line = missing_file_line(path)
           Annotation.new(
             start_line: line,
             end_line: line,
-            absolute_path: file,
+            absolute_path: relative_to,
             annotation_level: 'failure',
-            message: "`release.yaml` includes references to unknown #{file_description} file: `#{path}",
+            message: "`#{relative_to}` includes references to unknown #{file_description} file: `#{path}",
             title: "Missing #{file_description} file"
           )
         end.compact
@@ -33,17 +39,17 @@ def file_description
       private
 
       # Check whether script file exists
-      def relative_file_exists?(path)
+      def relative_file_exists?(path, relative_to: nil)
         # Find path relative to the release.yaml file
-        file_path = Pathname.new(file).dirname.join(path)
+        file_path = Pathname.new(relative_to || file).dirname.join(path)
         # Check whether this exists
         file_exists?(file_path)
       end
 
       # Search release.yaml line by line to find the file references
       def missing_file_line(path)
         File.readlines(file).each_with_index do |line, index|
-          return index + 1 if line.include?(path)
+          return index + 1 if line.include?(path.to_s)
         end
       end
     end