Detect in-place modifications on Strings

1 files changed, 36 insertions, 0 deletions

diff --git a/activerecord/test/cases/type/string_test.rb b/activerecord/test/cases/type/string_test.rb
new file mode 100644
index 0000000000..420177ed49
--- /dev/null
+++ b/activerecord/test/cases/type/string_test.rb
@@ -0,0 +1,36 @@
+require 'cases/helper'
+
+module ActiveRecord
+  class StringTypeTest < ActiveRecord::TestCase
+    test "type casting" do
+      type = Type::String.new
+      assert_equal "1", type.type_cast_from_user(true)
+      assert_equal "0", type.type_cast_from_user(false)
+      assert_equal "123", type.type_cast_from_user(123)
+    end
+
+    test "values are duped coming out" do
+      s = "foo"
+      type = Type::String.new
+      assert_not_same s, type.type_cast_from_user(s)
+      assert_not_same s, type.type_cast_from_database(s)
+    end
+
+    test "string mutations are detected" do
+      klass = Class.new(Base)
+      klass.table_name = 'authors'
+
+      author = klass.create!(name: 'Sean')
+      assert_not author.changed?
+
+      author.name << ' Griffin'
+      assert author.name_changed?
+
+      author.save!
+      author.reload
+
+      assert_equal 'Sean Griffin', author.name
+      assert_not author.changed?
+    end
+  end
+end