Add tests for `TypeMap#fetch` and push up to `TypeMap`

It doesn't make sense for the subclass to implement this method, and not
have it on the parent. We can also DRY up the implementation of
`#lookup` to be defined in terms of fetch, which will give us a single
point of entry

1 files changed, 15 insertions, 0 deletions

diff --git a/activerecord/test/cases/type/type_map_test.rb b/activerecord/test/cases/type/type_map_test.rb
index 4e32f92dd0..1e4eba1961 100644
--- a/activerecord/test/cases/type/type_map_test.rb
+++ b/activerecord/test/cases/type/type_map_test.rb
@@ -124,6 +124,21 @@ module ActiveRecord
         assert_equal mapping.lookup(3), 'string'
         assert_kind_of Type::Value, mapping.lookup(4)
       end
+
+      def test_fetch
+        mapping = TypeMap.new
+        mapping.register_type(1, "string")
+
+        assert_equal "string", mapping.fetch(1) { "int" }
+        assert_equal "int", mapping.fetch(2) { "int" }
+      end
+
+      def test_fetch_yields_args
+        mapping = TypeMap.new
+
+        assert_equal "foo-1-2-3", mapping.fetch("foo", 1, 2, 3) { |*args| args.join("-") }
+        assert_equal "bar-1-2-3", mapping.fetch("bar", 1, 2, 3) { |*args| args.join("-") }
+      end
     end
   end
 end