1 files changed, 35 insertions, 0 deletions
diff --git a/activerecord/test/cases/adapters/postgresql/type_lookup_test.rb b/activerecord/test/cases/adapters/postgresql/type_lookup_test.rb
new file mode 100644
index 0000000000..8212ed4263
--- /dev/null
+++ b/activerecord/test/cases/adapters/postgresql/type_lookup_test.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+require "cases/helper"
+
+class PostgresqlTypeLookupTest < ActiveRecord::PostgreSQLTestCase
+  setup do
+    @connection = ActiveRecord::Base.connection
+  end
+
+  test "array delimiters are looked up correctly" do
+    box_array = @connection.send(:type_map).lookup(1020)
+    int_array = @connection.send(:type_map).lookup(1007)
+
+    assert_equal ";", box_array.delimiter
+    assert_equal ",", int_array.delimiter
+  end
+
+  test "array types correctly respect registration of subtypes" do
+    int_array = @connection.send(:type_map).lookup(1007, -1, "integer[]")
+    bigint_array = @connection.send(:type_map).lookup(1016, -1, "bigint[]")
+    big_array = [123456789123456789]
+
+    assert_raises(ActiveModel::RangeError) { int_array.serialize(big_array) }
+    assert_equal "{123456789123456789}", @connection.type_cast(bigint_array.serialize(big_array))
+  end
+
+  test "range types correctly respect registration of subtypes" do
+    int_range = @connection.send(:type_map).lookup(3904, -1, "int4range")
+    bigint_range = @connection.send(:type_map).lookup(3926, -1, "int8range")
+    big_range = 0..123456789123456789
+
+    assert_raises(ActiveModel::RangeError) { int_range.serialize(big_range) }
+    assert_equal "[0,123456789123456789]", @connection.type_cast(bigint_range.serialize(big_range))
+  end
+end