lib/rbs/definition_builder.rb in rbs-1.7.1 vs lib/rbs/definition_builder.rb in rbs-1.8.0

@@ -779,12 +779,39 @@
 
       cc[key] ||= yield
     end
 
     def expand_alias(type_name)
-      entry = env.alias_decls[type_name] or raise "Unknown name for expand_alias: #{type_name}"
+      expand_alias2(type_name, [])
+    end
+
+    def expand_alias1(type_name)
+      entry = env.alias_decls[type_name] or raise "Unknown alias name: #{type_name}"
+      as = entry.decl.type_params.each.map { Types::Bases::Any.new(location: nil) }
+      expand_alias2(type_name, as)
+    end
+
+    def expand_alias2(type_name, args)
+      entry = env.alias_decls[type_name] or raise "Unknown alias name: #{type_name}"
+
       ensure_namespace!(type_name.namespace, location: entry.decl.location)
-      entry.decl.type
+      params = entry.decl.type_params.each.map(&:name)
+
+      unless params.size == args.size
+        as = "[#{args.join(", ")}]" unless args.empty?
+        ps = "[#{params.join(", ")}]" unless params.empty?
+
+        raise "Invalid type application: type = #{type_name}#{as}, decl = #{type_name}#{ps}"
+      end
+
+      type = entry.decl.type
+
+      unless params.empty?
+        subst = Substitution.build(params, args)
+        type = type.sub(subst)
+      end
+
+      type
     end
 
     def update(env:, except:, ancestor_builder:)
       method_builder = self.method_builder.update(env: env, except: except)