diff --git a/test/models/user_test.rb b/test/models/user_test.rb
new file mode 100644
index 0000000..85bbae5
--- /dev/null
+++ b/test/models/user_test.rb
@@ -0,0 +1,48 @@
+require "test_helper"
+
+class UserTest < ActiveSupport::TestCase
+  setup do
+    @user = FactoryBot.build(:user)
+  end
+
+  sub_test_case "password" do
+    def set_password(current_password, password, password_confirmation)
+      @user.current_password = current_password
+      @user.password = password
+      @user.password_confirmation = password_confirmation
+    end
+
+    sub_test_case "when current password is correct" do
+      test "password/confirmation is 8 characters" do
+        set_password(@user.password, "a" * 8, "a" * 8)
+        assert do
+          @user.valid?
+        end
+      end
+
+      test "password is 7 characters" do
+        set_password(@user.password, "a" * 7, "a" * 7)
+        assert do
+          !@user.valid?
+        end
+        assert_equal([:password], @user.errors.keys)
+      end
+
+      test "password != password_confirmation" do
+        set_password(@user.password, "a" * 8, "b" * 8)
+        assert do
+          !@user.valid?
+        end
+        assert_equal([:password], @user.errors.keys)
+      end
+    end
+
+    test "current_password is wrong" do
+      set_password("invalid_password", "a" * 8, "a" * 8)
+      assert do
+        !@user.valid?
+      end
+      assert_equal([:current_password], @user.errors.keys)
+    end
+  end
+end