Can I pass parameters to googletest test function

Question

After building my testfile, xxxxtest, with gtest can I pass a parameter when running the test, e.g. ./xxxxtest 100. I want to control my test function using the parameter, but I do not know how to use the para in my test, can you show me a sample in test?

possible duplicate of [How to pass parameters to the gtest](http://stackoverflow.com/questions/4818785/how-to-pass-parameters-to-the-gtest) — Rob Kennedy, Mar 19 '12 at 22:25
Here is another option: https://stackoverflow.com/questions/5260907/whats-the-way-to-access-argc-and-argv-inside-of-a-test-case-in-google-test-fram — Jason Christensen, Mar 17 '23 at 17:46

score 8 · Accepted Answer · answered Mar 01 '12 at 03:20

8

You could do something like the following:

main.cc

#include <string>
#include "gtest/gtest.h"
#include "my_test.h"

int main(int argc, char **argv) {
  std::string command_line_arg(argc == 2 ? argv[1] : "");
  testing::InitGoogleTest(&argc, argv);
  testing::AddGlobalTestEnvironment(new MyTestEnvironment(command_line_arg));
  return RUN_ALL_TESTS();
}

my_test.h

#include <string>
#include "gtest/gtest.h"

namespace {
std::string g_command_line_arg;
}

class MyTestEnvironment : public testing::Environment {
 public:
  explicit MyTestEnvironment(const std::string &command_line_arg) {
    g_command_line_arg = command_line_arg;
  }
};

TEST(MyTest, command_line_arg_test) {
  ASSERT_FALSE(g_command_line_arg.empty());
}

answered Mar 01 '12 at 03:20

Fraser

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What's the purpose of the `Environment` descendant? Why not just `g_command_line_arg = argc == 2 ? argv[1] : ""`? – Rob Kennedy Mar 19 '12 at 22:25
It's just to limit the scope of `g_command_line_arg`. Since it's in an unnamed namespace in my_test.h, it's not accessible outside of that translation unit. – Fraser Mar 20 '12 at 08:09
Why does it give me an error of `free(): invalid pointer `? – thedarkside ofthemoon Jul 16 '14 at 15:11
2

Shouldn't you the inialization of `command_line_arg` after the `InitGoogleTest`, so you don't interfere with parameters to gtest itself? – Philippos Nov 20 '17 at 10:09
What if I want to have multiple arguments to pass? – Priyanka M N Feb 12 '21 at 09:40

score 7 · Answer 2 · edited May 18 '22 at 15:59

7

You should be using Type-Parameterized Tests. https://github.com/google/googletest/blob/main/docs/advanced.md#type-parameterized-tests

Type-parameterized tests are like typed tests, except that they don't require you to know the list of types ahead of time. Instead, you can define the test logic first and instantiate it with different type lists later. You can even instantiate it more than once in the same program.

If you are designing an interface or concept, you can define a suite of type-parameterized tests to verify properties that any valid implementation of the interface/concept should have. Then, the author of each implementation can just instantiate the test suite with his type to verify that it conforms to the requirements, without having to write similar tests repeatedly.

Example

class FooTest: public ::testing::TestWithParam < int >{....};
    TEST_P(FooTest, DoesBar){
        ASSERT_TRUE(foo.DoesBar(GetParam());
    }

INSTANTIATE_TEST_CASE_P(OneToTenRange, FooTest, ::testing::Range(1, 10));

edited May 18 '22 at 15:59

AndersonMeng

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answered Sep 15 '14 at 17:48

Basanta

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NOTE: INSTANTIATE_TEST_CASE_P is _per-test-case_, and NOT _per-test_. This means that for every instantiation the entire test-case (all test functions of it) will be executed with the given parameter, not having the flexibility to pass parameters with more granularity, i.e. to a specific test-function instead. – Zuzu Corneliu Apr 23 '19 at 12:04
Also, you meant value-parameterized tests. – Zuzu Corneliu Apr 23 '19 at 12:36
I upvoted this comment because it is usually true. However, there are situations where tests depend on some external resource that may differ between environments. And before you say "that's what mocks are for", you can't mock *everything*. Think about testing a cell-phone capability that actually uses the cell network. You have to call *someone*... – slashingweapon Oct 22 '19 at 18:47

score 1 · Answer 3 · answered Jan 21 '20 at 23:39

If you don't want to make your own main() function. You can also consider passing information via environment variables.

In my case I just wanted a flag to show debug information or not, so I used getenv().

Another option would be to put any needed information in a text file and read it from the test.

Can I pass parameters to googletest test function

3 Answers3

main.cc

my_test.h

Linked