Support multiple test file matches in go to relevant file

Author: alexcrocha

lib/ruby_lsp/requests/go_to_relevant_file.rb

@@ -35,24 +35,34 @@ def perform
 
       #: -> Array[String]
       def find_relevant_paths
-        candidate_paths = Dir.glob(File.join("**", relevant_filename_pattern))
-        return [] if candidate_paths.empty?
-
-        find_most_similar_with_jaccard(candidate_paths).map { File.join(@workspace_path, _1) }
-      end
+        input_basename = File.basename(@path, ".rb")
 
-      #: -> String
-      def relevant_filename_pattern
-        input_basename = File.basename(@path, File.extname(@path))
+        patterns = if input_basename.match?(TEST_PATTERN)
+          # Test file -> find implementation
+          base = input_basename.gsub(TEST_PATTERN, "")
+          parent_dir = File.basename(File.dirname(@path))
 
-        relevant_basename_pattern =
-          if input_basename.match?(TEST_PATTERN)
-            input_basename.gsub(TEST_PATTERN, "")
+          # If test file is in a directory matching the implementation name (e.g., go_to_relevant_file/go_to_relevant_file_a_test.rb)
+          # also search for the parent directory name as the implementation file name
+          if base.include?(parent_dir) && base != parent_dir
+            ["**/#{base}.rb", "**/#{parent_dir}.rb"]
           else
-            "{{#{TEST_PREFIX_GLOB}}#{input_basename},#{input_basename}{#{TEST_SUFFIX_GLOB}}}"
+            ["**/#{base}.rb"]
           end
+        else
+          # Implementation file -> find tests (including in matching directory)
+          [
+            "**/{#{TEST_PREFIX_GLOB}}#{input_basename}.rb",
+            "**/#{input_basename}{#{TEST_SUFFIX_GLOB}}.rb",
+            "**/#{input_basename}/{#{TEST_PREFIX_GLOB}}*.rb",
+            "**/#{input_basename}/*{#{TEST_SUFFIX_GLOB}}.rb",
+          ]
+        end
+
+        candidate_paths = patterns.flat_map { |pattern| Dir.glob(pattern, base: @workspace_path) }
+        return [] if candidate_paths.empty?
 
-        "#{relevant_basename_pattern}#{File.extname(@path)}"
+        find_most_similar_with_jaccard(candidate_paths).map { |path| File.join(@workspace_path, path) }
       end
 
       # Using the Jaccard algorithm to determine the similarity between the