How to call Google Tests from another main function in C++ - c++

Question

I am trying to create a stack and test it using Google tests in an experiment with the C++ Google Test framework. I have set up the structure so I have a stack.h and stack.cpp for the implementation then I have a tests.cpp with the following code. I have several questions: first, is it possible to call my test functions from the main as I have done? Also, am I including everything correctly? Why are the build errors happening? Sorry, I am new to C++ and thanks for the help in advance. Here is the code and errors:
#include "stack.h"
#include "gtest/gtest.h"
TEST (StackTest, PushAndPeek) {
Stack<int> intStack;
int a = 12;
int b = 15;
EXPECT_EQ (12, intStack.push(a));
EXPECT_EQ (15, intStack.push(b));
EXPECT_EQ (15, intStack.peek()); //make sure adding in LIFO Order
EXPECT_EQ (15, intStack.peek()); //Should still be there
}
TEST (StackTest, PushAndPop) {
Stack<int> intStack;
int a = 12;
int b = 15;
EXPECT_EQ (12, intStack.push(a));
EXPECT_EQ (15, intStack.push(b));
EXPECT_EQ (15, intStack.pop()); //make sure adding in LIFO Order
EXPECT_EQ (12, intStack.pop()); //Should have removed 15, then removed 12
EXPECT_EQ (-1, intStack.pop()); //Should return -1 because there is nothing on the stack
}
Then in my main.cpp I have:
#include <iostream>
#include <string>
#include "gtest/gtest.h"
#include "stack.h"
using namespace std;
int main(int argc, char * argv[])
{
string input;
cout << "Hey there! If you wanna run the tests, type in tests. \nOther wise just hit enter to continue...\n";
getline (cin, input);
if(input == "tests"){
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
return 0;
}
However, I am compiling using XCode and it is failing to build with the following reasons:
Undefined symbols for architecture x86_64:
"Stack<int>::pop()", referenced from:
StackTest_PushAndPop_Test::TestBody() in tests.o
"Stack<int>::peek()", referenced from:
StackTest_PushAndPeek_Test::TestBody() in tests.o
"Stack<int>::push(int&)", referenced from:
StackTest_PushAndPeek_Test::TestBody() in tests.o
StackTest_PushAndPop_Test::TestBody() in tests.o
"Stack<int>::Stack()", referenced from:
StackTest_PushAndPeek_Test::TestBody() in tests.o
StackTest_PushAndPop_Test::TestBody() in tests.o
"Stack<int>::~Stack()", referenced from:
StackTest_PushAndPeek_Test::TestBody() in tests.o
StackTest_PushAndPop_Test::TestBody() in tests.o
"testing::internal::EqFailure(char const*, char const*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool)", referenced from:
testing::AssertionResult testing::internal::CmpHelperEQ<int, int>(char const*, char const*, int const&, int const&) in tests.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
EDIT:
By including the stack.cpp I resolved the errors related to that, but I still have the following errors:
Undefined symbols for architecture x86_64:
"testing::internal::EqFailure(char const*, char const*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool)", referenced from:
testing::AssertionResult testing::internal::CmpHelperEQ<int, int>(char const*, char const*, int const&, int const&) in tests.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Answer 1

At first sight that looks as if you had made a beginners mistake with templates: Templates have to be implemented in the header file, you cannot separate them in header and .cpp file like normal classes and functions. Just search for "undefined refernce" and "template" on SO and you will get a lot of information on that matter :-)