Avoid keeping empty arrays inside constant completion candidates (#3680)

Author: vinistock

lib/ruby_indexer/lib/ruby_indexer/index.rb

@@ -293,11 +293,13 @@ def constant_completion_candidates(name, nesting)
       entries.concat(@entries_tree.search(name))
 
       # Filter only constants since methods may have names that look like constants
-      entries.each do |definitions|
+      entries.select! do |definitions|
         definitions.select! do |entry|
           entry.is_a?(Entry::Constant) || entry.is_a?(Entry::ConstantAlias) ||
             entry.is_a?(Entry::Namespace) || entry.is_a?(Entry::UnresolvedConstantAlias)
         end
+
+        definitions.any?
       end
 
       entries.uniq!

lib/ruby_indexer/test/index_test.rb

@@ -1993,6 +1993,9 @@ def Qux
 
       candidates = @index.constant_completion_candidates("Q", [])
       refute_includes(candidates.flat_map { |entries| entries.map(&:name) }, "Qux")
+
+      candidates = @index.constant_completion_candidates("Qux", [])
+      assert_equal(0, candidates.length)
     end
 
     def test_constant_completion_candidates_for_empty_name