gtest - How to run the same code in the beginning of some functions

Question

I have some functions on my gtest, like below. (don't mind the syntax)

TEST(HotelTest, test1)
{
   MyObj obj;
   int a = obj.doStuff(1);

   EXPECT_EQ(test1, a);
}

TEST(HotelTest, test2)
{
   MyObj obj;
   int a = obj.doStuff(2);

   EXPECT_EQ(test2, a);
}

TEST(HotelTest, test3)
{
   MyObj obj;
   int a = obj.doStuff(3);

   EXPECT_EQ(test3, a);
}

TEST(HotelTest, test4)
{
   MyObj obj;
   int a = obj.doStuff(4);

   EXPECT_EQ(test4, a);
}

As you can see, there is code repeated all over the functions.

QUESTION: Is there any way to avoid this? I mean... Something like an inline function where I could store that repeated code in another place and then just call?

P.S. I really need to have different TEST functions. This example is just to show the problem.

Thanks in advance:)

Answer 1

At the very least, you could use test fixtures.

This will allow you to avoid duplicating the MyObj obj; line in each case:

class HotelTest : public ::testing::Test {
 protected:
  MyObj obj;
};

TEST_F(HotelTest, test1) {
   int a = obj.doStuff(1);
   EXPECT_EQ(test1, a);
}

TEST_F(HotelTest, test2) {
   int a = obj.doStuff(2);
   EXPECT_EQ(test2, a);
}

If your calls to obj.doStuff are more involved than a single command, you can wrap these in a function of the fixture too:

class HotelTest : public ::testing::Test {
 protected:
  int doStuff(int i) { return obj.doStuff(i); }
  MyObj obj;
};

TEST_F(HotelTest, test1) {
   EXPECT_EQ(test1, doStuff(1));
}

TEST_F(HotelTest, test2) {
   EXPECT_EQ(test2, doStuff(2));
}

Finally, you might be able to make use of the more advanced value-parameterised tests. This example would run the test case four times. On the first iteration GetParam() would yield 1, on the second 2 and so on up to 4 as specified by ::testing::Range(1, 5).

class HotelTest : public ::testing::TestWithParam<int> {
 protected:
  int doStuff(int i) { return obj.doStuff(i); }
  MyObj obj;
};

TEST_P(HotelTest, test) {
   EXPECT_EQ(testx, doStuff(GetParam()));
}

INSTANTIATE_TEST_CASE_P(AllHotelTests, HotelTest, ::testing::Range(1, 5));