c++ unit testing check output is correct
assert, c++, cout, output, unit-testing
Solution
The solution is not to hard-code the output stream. Pass a reference to `std::ostream` to your code somehow, and use `std::stringstream` to collect the output in test environment.
For example, this is the content of your "another .cpp" file:
void toBeTested(std::ostream& output) {
output << "this is the correct output";
}
So in your production/release code you may pass `std::cout` to the function:
void productionCode() {
toBeTested(std::cout);
}
while in the test environment you may collect the output to a sting stream and check it for correctness:
// test.cpp
#include <sstream>
#include <cassert>
void test() {
std::stringstream ss;
toBeTested(ss);
assert(ss.str() == "this is the correct output");
}
Problem
If I want to write my own test.cpp that checks if another .cpp file is outputting the way I want it to output, is there anyway to do it without explicitly printing it? In other words, is there anything such as ``` assert(output_of_file_being_tested, "this is the correct output"); ``` where output_of_file_being_tested is something that's supposed to be "cout"ed.