add tests for lammps configuration introspection via library interface

unittest/c-library/CMakeLists.txt

@@ -11,3 +11,22 @@ add_executable(test_library_properties test_library_properties.cpp test_main.cpp
 target_link_libraries(test_library_properties PRIVATE lammps GTest::GTest GTest::GMock)
 target_compile_definitions(test_library_properties PRIVATE -DTEST_INPUT_FOLDER=${CMAKE_CURRENT_SOURCE_DIR})
 add_test(LibraryProperties test_library_properties)
+
+set(PKG_COUNT 0)
+foreach(PKG ${STANDARD_PACKAGES} ${SUFFIX_PACKAGES})
+  if(PKG_${PKG})
+    MATH(EXPR PKG_COUNT "${PKG_COUNT}+1")
+  endif()
+endforeach()
+
+if(PKG_MANYBODY)
+  set(HAS_MANYBODY 1)
+else()
+  set(HAS_MANYBODY 0)
+endif()
+
+add_executable(test_library_config test_library_config.cpp test_main.cpp)
+target_link_libraries(test_library_config PRIVATE lammps GTest::GTest GTest::GMock)
+target_compile_definitions(test_library_config PRIVATE -DTEST_INPUT_FOLDER=${CMAKE_CURRENT_SOURCE_DIR}
+        -DNUM_LAMMPS_PACKAGES=${PKG_COUNT} -DLAMMPS_HAS_MANYBODY=${HAS_MANYBODY})
+add_test(LibraryConfig test_library_config)

unittest/c-library/test_library_config.cpp

@@ -0,0 +1,61 @@
+// unit tests for checking LAMMPS configuration settings  through the library interface
+
+#include "library.h"
+#include "lammps.h"
+#include <string>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+#include "test_main.h"
+
+#define STRINGIFY(val) XSTR(val)
+#define XSTR(val) #val
+
+using ::testing::HasSubstr;
+using ::testing::StartsWith;
+
+class LAMMPS_config : public ::testing::Test {
+protected:
+    void *lmp;
+    std::string INPUT_DIR = STRINGIFY(TEST_INPUT_FOLDER);
+
+    LAMMPS_config(){};
+    ~LAMMPS_config() override{};
+
+    void SetUp() override
+    {
+        const char *args[] = {"LAMMPS_test", "-log",      "none",
+                              "-echo",       "screen",    "-nocite",
+                              "-var",        "input_dir", STRINGIFY(TEST_INPUT_FOLDER)};
+
+        char **argv = (char **)args;
+        int argc    = sizeof(args) / sizeof(char *);
+
+        ::testing::internal::CaptureStdout();
+        lmp                = lammps_open_no_mpi(argc, argv, NULL);
+        std::string output = ::testing::internal::GetCapturedStdout();
+        if (verbose) std::cout << output;
+        EXPECT_THAT(output, StartsWith("LAMMPS ("));
+    }
+    void TearDown() override
+    {
+        ::testing::internal::CaptureStdout();
+        lammps_close(lmp);
+        std::string output = ::testing::internal::GetCapturedStdout();
+        EXPECT_THAT(output, HasSubstr("Total wall time:"));
+        if (verbose) std::cout << output;
+        lmp = nullptr;
+    }
+};
+
+TEST(LAMMPS_config, package_count)
+{
+    EXPECT_EQ(lammps_config_package_count(), NUM_LAMMPS_PACKAGES);
+};
+
+TEST(LAMMPS_config, has_package)
+{
+    EXPECT_EQ(lammps_config_has_package("MANYBODY"), LAMMPS_HAS_MANYBODY);
+};
+