Update tests to latest version of gtest #806
Description
In https://github.com/NREL/ssc/runs/6181437239?check_suite_focus=true, the tests failed due to an incompatibility with the latest version of gtest with the following error:
In file included from /Users/runner/work/ssc/ssc/ssc/test/ssc_test/cmod_tcstrough_empirical_test.cpp:23:
In file included from /Users/runner/work/ssc/ssc/googletest/googletest/include/gtest/gtest.h:60:
In file included from /Users/runner/work/ssc/ssc/googletest/googletest/include/gtest/gtest-death-test.h:43:
In file included from /Users/runner/work/ssc/ssc/googletest/googletest/include/gtest/internal/gtest-death-test-internal.h:46:
In file included from /Users/runner/work/ssc/ssc/googletest/googletest/include/gtest/gtest-matchers.h:48:
In file included from /Users/runner/work/ssc/ssc/googletest/googletest/include/gtest/gtest-printers.h:114:
/Users/runner/work/ssc/ssc/googletest/googletest/include/gtest/internal/gtest-internal.h:477:40: error: cannot initialize return object of type 'testing::Test *' with an rvalue of type 'csp_trough_EmpiricalTroughCmod_Phoenix_NoFinancial_Test '
Test CreateTest() override { return new TestClass; }
^~~
/Users/runner/work/ssc/ssc/ssc/test/ssc_test/cmod_tcstrough_empirical_test.cpp:233:1: note: in instantiation of member function 'testing::internal::TestFactoryImpl<csp_trough_EmpiricalTroughCmod_Phoenix_NoFinancial_Test>::CreateTest' requested here
NAMESPACE_TEST(csp_trough, EmpiricalTroughCmod, Phoenix_NoFinancial)
^
/Users/runner/work/ssc/ssc/ssc/test/shared_test/vs_google_test_explorer_namespace.h:45:3: note: expanded from macro 'NAMESPACE_TEST'
NAMESPACE_GTEST_TEST_(namespace_name, test_case_name, test_name,
^
/Users/runner/work/ssc/ssc/ssc/test/shared_test/vs_google_test_explorer_namespace.h:38:13: note: expanded from macro 'NAMESPACE_GTEST_TEST_'
new ::testing::internal::TestFactoryImpl<
^
16 errors generated.
The short term fix was to pin the version of gtest at the last version that worked: #804
This issue covers the long term fix: rewriting our tests to remove the errors.