Tests Too DRY? Make Them DAMP!

Though the DRY ("Don't Repeat Yourself") principle is great for production code, tests don't test themselves.

Bad

class ForumTest : public ::testing::Test {
 protected:
  void SetUp() override {
    for (auto user : users_) {
      forum_.Register(user);
    }
  }

  Forum forum_;
  std::vector<User> users_ = {User("Alice"), User("Bob")};
}

TEST_F(ForumTest, CanRegisterMultipleUsers) {
  for (auto user : users_) {
    EXPECT_TRUE(forum_.HasRegisteredUser(user));
  }
}

Tests should optimize for readability, even at the expense of redundancy. Prefer the DAMP ("Descriptive and Meaningful Phrases") principle.

Good

TEST(ForumTest, CanRegisterMultipleUsers) {
  Forum forum;
  User user1("Alice");
  User user2("Bob");
  forum.Register(user1);
  forum.Register(user2);

  EXPECT_TRUE(forum.HasRegisteredUser(user1));
  EXPECT_TRUE(forum.HasRegisteredUser(user2));
}