Test cases_config using catch2

[dafeda]

Introducing Tmpdir catch2 fixture similar
to tmpdir in pytest.
Copied from ecl.

Issue
Resolves #2387

[pinkwah]

Don't add namespace aliases to header files as they bleed into source files.

[dafeda]

Ok, thanks.

Should we update this from ecl?

https://github.com/equinor/ecl/blob/master/lib/tests/tmpdir.hpp

[eivindjahren]

You probably want the cases_config_free to happen in the GIVEN scope.

[eivindjahren]

Maybe Then("Write and read preserves get/set iteration_number behavior"). The GIVEN, WHEN and THEN macros refer to the 3xA concept from BDD (Assemble, Act, Assert) and are more or less aliases of SECTION.

Generally, unless the test is very simple, I think its more readable if all three are present, in the given->when->then order.

GIVEN("A cases config with iteration number") {
        cases_config_type *cases_config = cases_config_alloc();
        int iteration_number = GENERATE(1,2,3,14);
        cases_config_set_int(cases_config, "iteration_number", iteration_number);
         
        WHEN("The cases config is written and then read back") {
            fs::path file_path = dirname / "TEST_CASES_CONFIG";
            cases_config_fwrite(cases_config, file_path.c_str());
            cases_config_fread(cases_config, file_path.c_str());
            
            THEN("Iteration number remains the same") {
                REQUIRE(cases_config_get_iteration_number(cases_config) == teration_number);
            }
        }
         cases_config_free(cases_config);
    }
}

[dafeda]

This was a very helpful example, thanks!

I've updated the code to use this and the new tmpdir.

[eivindjahren]

LGTM