Add check whether problem has a translation

test/models/problem_test.rb

@@ -1,7 +1,16 @@
 require 'test_helper'
 
 class ProblemTest < ActiveSupport::TestCase
-  # test "the truth" do
-  #   assert true
-  # end
+  test "should save correct problem" do
+    problem = Problem.new
+    assert problem.save
+  end
+
+  test "is_translated? should return false for missing translation" do
+    assert_not problems(:three).is_translated?
+  end
+
+  test "is_translated? should return true for existing translation" do
+    assert problems(:one).is_translated?
+  end
 end