mpi.cpp

#include <doctest/extensions/doctest_mpi.h>

int f_for_test(int rank);

int f_for_test(int rank) {
    if (rank == 0) {
        return 10;
    } else if (rank == 1) {
        return 11;
    }
    return 0;
}

MPI_TEST_CASE("Parallel test on 2 processes", 2) { // if MPI_SIZE < 2, report test can't be run
    // 3 objects accessible in the test:
    //    test_comm: MPI_Comm of size 2
    //    test_rank: integer of value the rank of the process in test_comm
    //    test_nb_procs: integer of value the size of the process (here: 2)

    int x = f_for_test(test_rank);

    MPI_CHECK(0, x == 10); // CHECK for rank 0, that x==10
    MPI_CHECK(1, x == 11); // CHECK for rank 1, that x==11
                           // MPI_CHECK( 2,  x==0 ); // will trigger a static assert because non-existing rank
}

MPI_TEST_CASE("Parallel test on 3 processes (failing)", 3) {
    int x = f_for_test(test_rank);

    MPI_CHECK(0, x == 10); // CHECK for rank 0, that x==10
    MPI_CHECK(1, x == 11); // CHECK for rank 1, that x==11
    MPI_CHECK(2, x == -1); // CHECK for rank 2, that x==-1 (which is not the case -> will trigger a failure report)
}

MPI_TEST_CASE("Parallel tests with subcases", 2) {

    SUBCASE("sub_case 0") {
        CHECK(test_nb_procs == 2);
    }
    SUBCASE("sub_case 1") {
        CHECK(test_rank == 0); // should fail on proc 1
    }
}