Merge pull request #52 from TREX-CoE/unit-testing

Unit testing

Makefile.am

@@ -30,8 +30,11 @@
 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+# =============== SETTINGS =============== #
+
 ACLOCAL_AMFLAGS = -I m4
 CLEANFILES = trexio.mod
+BUILT_SOURCES = trexio.mod
 
 VERSION_MAJOR   = @VERSION_MAJOR@
 VERSION_MINOR   = @VERSION_MINOR@
@@ -42,6 +45,7 @@ SUBDIRS =
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = pkgconfig/trexio.pc
 
+# =============== BUILD =============== #
 
 trexio_h = $(srcdir)/include/trexio.h
 trexio_f = $(srcdir)/include/trexio_f.f90
@@ -72,21 +76,67 @@ ORG_FILES = \
 
 src_libtrexio_la_SOURCES = $(SOURCES)
 
-TESTS = tests/test_c tests/test_f
+# =============== TESTS =============== #
+
+TESTS_C = \
+  tests/open_hdf5 \
+  tests/open_text \
+  tests/io_num_hdf5 \
+  tests/io_num_text \
+  tests/io_dset_float_hdf5 \
+  tests/io_dset_float_text \
+  tests/io_dset_int_hdf5 \
+  tests/io_dset_int_text \
+  tests/io_str_hdf5 \
+  tests/io_str_text \
+  tests/io_dset_str_hdf5 \
+  tests/io_dset_str_text \
+  tests/overwrite_all_hdf5 \
+  tests/overwrite_all_text \
+  tests/io_all
+
+TESTS_F = \
+  tests/test_f
+
+TESTS = $(TESTS_C) $(TESTS_F)
 check_PROGRAMS = $(TESTS)
 
-tests_test_c_DEPENDENCIES = $(trexio_h)
+# specify common LDADD options for all tests
-tests_test_c_SOURCES = tests/test.c $(trexio_h)
+LDADD = src/libtrexio.la
-tests_test_c_LDADD   = src/libtrexio.la
+
-tests_test_c_LDFLAGS = -no-install
+# in principal, specifying -no-install (see below) is not mandatory
+# for the tests to compile and pass, but the produced test binaries differ 
+tests_open_hdf5_LDFLAGS = -no-install
+tests_open_text_LDFLAGS = -no-install
+tests_io_num_hdf5_LDFLAGS = -no-install
+tests_io_num_text_LDFLAGS = -no-install
+tests_io_dset_float_hdf5_LDFLAGS = -no-install
+tests_io_dset_float_text_LDFLAGS = -no-install
+tests_io_dset_int_hdf5_LDFLAGS = -no-install
+tests_io_dset_int_text_LDFLAGS = -no-install
+tests_io_str_hdf5_LDFLAGS = -no-install
+tests_io_str_text_LDFLAGS = -no-install
+tests_io_dset_str_hdf5_LDFLAGS = -no-install
+tests_io_dset_str_text_LDFLAGS = -no-install
+tests_overwrite_all_hdf5_LDFLAGS = -no-install
+tests_overwrite_all_text_LDFLAGS = -no-install
+tests_io_all_LDFLAGS = -no-install
 
 test_trexio_f = $(srcdir)/tests/trexio_f.f90
 
-tests_test_f_DEPENDENCIES = $(test_trexio_f)
+$(test_trexio_f): $(trexio_f)
+	cp $(trexio_f) $(test_trexio_f)
+
+trexio.mod: tests/trexio_f.o
+
 tests_test_f_SOURCES = $(test_trexio_f) tests/test_f.f90
-tests_test_f_LDADD   = src/libtrexio.la
 tests_test_f_LDFLAGS = -no-install
 
+clean-local:
+	-rm -rf -- *.dir/ *.h5
+
+# =============== DOCUMENTATION =============== #
+
 HTML_FILES =  docs/trexio.css            \
               docs/index.html            \
               docs/Sparse.html           \
@@ -101,17 +151,13 @@ dist_html_DATA = $(HTML_FILES)
 
 $(HTML_FILES): docs/index.html
 
-$(test_trexio_f): $(trexio_f)
+# =============== DEVELOPER MODE =============== #
-	cp $(trexio_f) $(test_trexio_f)
-
-clean-local:
-	-rm -rf -- test_write.dir/ test_write_f.dir/ test_write.h5 test_write_f.h5
 
 if TREXIO_DEVEL
 
 CLEANFILES += $(SOURCES) $(trexio_f) $(trexio_h)
 
-BUILT_SOURCES = $(SOURCES) $(trexio_f) $(test_trexio_f)
+BUILT_SOURCES += $(SOURCES) $(trexio_f) $(test_trexio_f)
 
 
 $(SOURCES): $(trexio_f)
@@ -120,7 +166,7 @@ src/trexio.c: $(trexio_h)
 $(trexio_f): $(ORG_FILES)
 	cd $(srcdir)/tools && ./build_trexio.sh
 
-docs/index.html: $(SOURCES) $(srcdir)/src/README.org
+docs/index.html: $(ORG_FILES) $(srcdir)/src/README.org
 	cd $(srcdir)/tools && ./build_doc.sh
 
 cppcheck: cppcheck.out
@@ -136,3 +182,4 @@ cppcheck.out: $(trexio_h)
 .PHONY: cppcheck
 
 endif
+

src/templates_front/templator_front.org

@@ -121,7 +121,7 @@ typedef int32_t trexio_exit_code;
 
       #+NAME: table-exit-codes
    | Macro                        | Code | Description                          |
-   |------------------------------+------+----------------------------------------|
+   |------------------------------+------+--------------------------------------|
    | ~TREXIO_FAILURE~             |   -1 | 'Unknown failure'                    |
    | ~TREXIO_SUCCESS~             |    0 | 'Success'                            |
    | ~TREXIO_INVALID_ARG_1~       |    1 | 'Invalid argument 1'                 |
@@ -136,7 +136,7 @@ typedef int32_t trexio_exit_code;
    | ~TREXIO_ALLOCATION_FAILED~   |   10 | 'Allocation failed'                  |
    | ~TREXIO_HAS_NOT~             |   11 | 'Element absent'                     |
    | ~TREXIO_INVALID_NUM~         |   12 | 'Invalid dimensions'                 |
-   | ~TREXIO_NUM_ALREADY_EXISTS~  |   13 | 'Dimensioning variable already exists' |
+   | ~TREXIO_ATTR_ALREADY_EXISTS~ |   13 | 'Attribute (num/str) already exists' |
    | ~TREXIO_DSET_ALREADY_EXISTS~ |   14 | 'Dataset already exists'             |
    | ~TREXIO_OPEN_ERROR~          |   15 | 'Error opening file'                 |
    | ~TREXIO_LOCK_ERROR~          |   16 | 'Error locking file'                 |
@@ -192,7 +192,7 @@ return '\n'.join(result)
    #define  TREXIO_ALLOCATION_FAILED       ((trexio_exit_code) 10)
    #define  TREXIO_HAS_NOT                 ((trexio_exit_code) 11)
    #define  TREXIO_INVALID_NUM             ((trexio_exit_code) 12)
-   #define  TREXIO_NUM_ALREADY_EXISTS      ((trexio_exit_code) 13)
+   #define  TREXIO_ATTR_ALREADY_EXISTS     ((trexio_exit_code) 13)
    #define  TREXIO_DSET_ALREADY_EXISTS     ((trexio_exit_code) 14)
    #define  TREXIO_OPEN_ERROR              ((trexio_exit_code) 15)
    #define  TREXIO_LOCK_ERROR              ((trexio_exit_code) 16)
@@ -220,7 +220,7 @@ return '\n'.join(result)
       integer(trexio_exit_code), parameter :: TREXIO_ALLOCATION_FAILED       = 10
       integer(trexio_exit_code), parameter :: TREXIO_HAS_NOT                 = 11
       integer(trexio_exit_code), parameter :: TREXIO_INVALID_NUM             = 12
-      integer(trexio_exit_code), parameter :: TREXIO_NUM_ALREADY_EXISTS      = 13
+      integer(trexio_exit_code), parameter :: TREXIO_ATTR_ALREADY_EXISTS     = 13
       integer(trexio_exit_code), parameter :: TREXIO_DSET_ALREADY_EXISTS     = 14
       integer(trexio_exit_code), parameter :: TREXIO_OPEN_ERROR              = 15
       integer(trexio_exit_code), parameter :: TREXIO_LOCK_ERROR              = 16
@@ -860,7 +860,7 @@ trexio_write_$group_num$_64 (trexio_t* const file, const int64_t num)
 {
   if (file == NULL) return TREXIO_INVALID_ARG_1;
   if (num  <  0   ) return TREXIO_INVALID_ARG_2;
-  if (trexio_has_$group_num$(file) == TREXIO_SUCCESS) return TREXIO_NUM_ALREADY_EXISTS;
+  if (trexio_has_$group_num$(file) == TREXIO_SUCCESS) return TREXIO_ATTR_ALREADY_EXISTS;
 
   switch (file->back_end) {
 
@@ -921,7 +921,7 @@ trexio_write_$group_num$_32 (trexio_t* const file, const int32_t num)
 
   if (file == NULL) return TREXIO_INVALID_ARG_1;
   if (num  <  0   ) return TREXIO_INVALID_ARG_2;
-  if (trexio_has_$group_num$(file) == TREXIO_SUCCESS) return TREXIO_NUM_ALREADY_EXISTS;
+  if (trexio_has_$group_num$(file) == TREXIO_SUCCESS) return TREXIO_ATTR_ALREADY_EXISTS;
 
   switch (file->back_end) {
 
@@ -1981,7 +1981,7 @@ trexio_write_$group_str$ (trexio_t* const file, const char* str, const uint32_t
   if (file == NULL) return TREXIO_INVALID_ARG_1;
   if (str  == NULL) return TREXIO_INVALID_ARG_2;
   if (max_str_len <= 0) return TREXIO_INVALID_ARG_3;
-  if (trexio_has_$group_str$(file) == TREXIO_SUCCESS) return TREXIO_NUM_ALREADY_EXISTS;
+  if (trexio_has_$group_str$(file) == TREXIO_SUCCESS) return TREXIO_ATTR_ALREADY_EXISTS;
 
   size_t len_write = strlen(str);
   if (max_str_len < len_write) return TREXIO_INVALID_STR_LEN;  

src/templates_hdf5/templator_hdf5.org

@@ -233,14 +233,6 @@ trexio_hdf5_write_$group_num$ (trexio_t* const file, const uint64_t num)
     trexio_exit_code rc = trexio_hdf5_read_$group_num$(file, &(infile_num));
     if (rc != TREXIO_SUCCESS) return rc;
 
-    if (infile_num != num) {
-
-      if (infile_num != 0) {
-
-	return TREXIO_NUM_ALREADY_EXISTS;
-
-      } else {
-
     const hid_t dtype = H5Tcopy(H5T_NATIVE_UINT64);
     const hid_t num_id = H5Aopen(f->$group$_group, $GROUP_NUM$_NAME, H5P_DEFAULT);
     if (num_id <= 0) return TREXIO_INVALID_ID;
@@ -250,8 +242,7 @@ trexio_hdf5_write_$group_num$ (trexio_t* const file, const uint64_t num)
     
     H5Aclose(num_id);
     H5Tclose(dtype);
-      }
+
-    }
     return TREXIO_SUCCESS;
   }
 

tests/.gitignore

@@ -1,14 +1,15 @@
-libtrexio.so
+# Ignore all
-trexio_f.o
+*
+# Unignore all with extensions
+!*.*
+
 trexio_f.f90
 trexio.mod
 
-test_c
+*.o
-test_f
-
 *.log
 *.trs
+.dirstamp
 
 *.h5
 */
-

tests/io_all.c

@@ -12,18 +12,18 @@ int main() {
 /*============== Main test launcher ================*/
 
   int rc;
-  rc = system("rm -rf test_write.h5");
+  rc = system("rm -rf test_all.h5");
   assert (rc == 0);
-  test_write("test_write.h5", TREXIO_HDF5);
+  test_write("test_all.h5", TREXIO_HDF5);
-  test_read ("test_write.h5", TREXIO_HDF5);
+  test_read ("test_all.h5", TREXIO_HDF5);
-  rc = system("rm -rf test_write.h5");
+  rc = system("rm -rf test_all.h5");
   assert (rc == 0);
 
-  rc = system("rm -rf test_write.dir");
+  rc = system("rm -rf test_all.dir");
   assert (rc == 0);
-  test_write("test_write.dir", TREXIO_TEXT);
+  test_write("test_all.dir", TREXIO_TEXT);
-  test_read ("test_write.dir", TREXIO_TEXT);
+  test_read ("test_all.dir", TREXIO_TEXT);
-  rc = system("rm -rf test_write.dir");
+  rc = system("rm -rf test_all.dir");
   assert (rc == 0);
 
   return 0;
@@ -68,7 +68,7 @@ int test_write(const char* file_name, const back_end_t backend) {
                 	 "H" ,
 	                 "H" };
   
-  const char* sym = "B3U and some stuff";
+  const char* sym = "B3U with some comments";
 /*================= START OF TEST ==================*/
 
   // open file in 'write' mode
@@ -113,7 +113,7 @@ int test_write(const char* file_name, const back_end_t backend) {
   // should not work: try to overwrite the num variable
   rc = trexio_write_nucleus_num(file,25);
   printf("Test error message: %s\n", trexio_string_of_error(rc));
-  assert (rc == TREXIO_NUM_ALREADY_EXISTS);
+  assert (rc == TREXIO_ATTR_ALREADY_EXISTS);
 
   // should not work: try to overwrite the dset
   coord[0] = 666.666;

tests/io_dset_float_hdf5.c

@@ -0,0 +1,148 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_BACKEND 	TREXIO_HDF5
+#define TREXIO_FILE 	"test_dset_f.h5"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to write a dataset with numerical (floating point) values into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+  double coord[36] = {
+  0.00000000 ,  1.39250319 ,  0.00000000 ,
+ -1.20594314 ,  0.69625160 ,  0.00000000 ,
+ -1.20594314 , -0.69625160 ,  0.00000000 ,
+  0.00000000 , -1.39250319 ,  0.00000000 ,
+  1.20594314 , -0.69625160 ,  0.00000000 ,
+  1.20594314 ,  0.69625160 ,  0.00000000 ,
+ -2.14171677 ,  1.23652075 ,  0.00000000 ,
+ -2.14171677 , -1.23652075 ,  0.00000000 ,
+  0.00000000 , -2.47304151 ,  0.00000000 ,
+  2.14171677 , -1.23652075 ,  0.00000000 ,
+  2.14171677 ,  1.23652075 ,  0.00000000 ,
+  0.00000000 ,  2.47304151 ,  0.00000000 ,
+  };
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write numerical attribute in an empty file
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+  
+  // write numerical dataset in a file
+  rc = trexio_write_nucleus_coord(file, coord);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a dataset in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written dataset exists
+  rc = trexio_has_nucleus_coord(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that another dataset does not exist
+  rc = trexio_has_mo_coefficient(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to read a dataset with numerical (floating point) values from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  int num;
+  double* coord;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read numerical attribute from the file
+  rc = trexio_read_nucleus_num(file, &num);
+  assert (rc == TREXIO_SUCCESS);
+  assert (num == 12);
+
+  // read numerical (floating point) dataset from the file
+  coord = (double*) calloc(3*num, sizeof(double));
+  rc = trexio_read_nucleus_coord(file, coord);
+  assert (rc == TREXIO_SUCCESS);
+
+  double x = coord[30] - 2.14171677;
+  assert( x*x < 1.e-14 );
+  free(coord);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_dset (TREXIO_FILE, TEST_BACKEND);
+  test_has_dset   (TREXIO_FILE, TEST_BACKEND);
+  test_read_dset  (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/io_dset_float_text.c

@@ -0,0 +1,148 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_BACKEND 	TREXIO_TEXT
+#define TREXIO_FILE 	"test_dset_f.dir"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to write a dataset with numerical (floating point) values into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+  double coord[36] = {
+  0.00000000 ,  1.39250319 ,  0.00000000 ,
+ -1.20594314 ,  0.69625160 ,  0.00000000 ,
+ -1.20594314 , -0.69625160 ,  0.00000000 ,
+  0.00000000 , -1.39250319 ,  0.00000000 ,
+  1.20594314 , -0.69625160 ,  0.00000000 ,
+  1.20594314 ,  0.69625160 ,  0.00000000 ,
+ -2.14171677 ,  1.23652075 ,  0.00000000 ,
+ -2.14171677 , -1.23652075 ,  0.00000000 ,
+  0.00000000 , -2.47304151 ,  0.00000000 ,
+  2.14171677 , -1.23652075 ,  0.00000000 ,
+  2.14171677 ,  1.23652075 ,  0.00000000 ,
+  0.00000000 ,  2.47304151 ,  0.00000000 ,
+  };
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write numerical attribute in an empty file
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+  
+  // write numerical dataset in a file
+  rc = trexio_write_nucleus_coord(file, coord);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a dataset in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written dataset exists
+  rc = trexio_has_nucleus_coord(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that another dataset does not exist
+  rc = trexio_has_mo_coefficient(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to read a dataset with numerical (floating point) values from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  int num;
+  double* coord;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read numerical attribute from the file
+  rc = trexio_read_nucleus_num(file, &num);
+  assert (rc == TREXIO_SUCCESS);
+  assert (num == 12);
+
+  // read numerical (floating point) dataset from the file
+  coord = (double*) calloc(3*num, sizeof(double));
+  rc = trexio_read_nucleus_coord(file, coord);
+  assert (rc == TREXIO_SUCCESS);
+
+  double x = coord[30] - 2.14171677;
+  assert( x*x < 1.e-14 );
+  free(coord);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_dset (TREXIO_FILE, TEST_BACKEND);
+  test_has_dset   (TREXIO_FILE, TEST_BACKEND);
+  test_read_dset  (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/io_dset_int_hdf5.c

@@ -0,0 +1,134 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_BACKEND 	TREXIO_HDF5
+#define TREXIO_FILE 	"test_dset_i.h5"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to write a dataset with numerical (int) values into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+  int nucl_index[12] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write numerical attribute in an empty file
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+  
+  // write numerical (integer) dataset in a file
+  rc = trexio_write_basis_nucleus_index(file, nucl_index);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a dataset in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file 
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written dataset exists
+  rc = trexio_has_basis_nucleus_index(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that another dataset does not exist
+  rc = trexio_has_mo_coefficient(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to read a dataset with numericali (int) values from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  int num;
+  int* nucl_index;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read numerical attribute from the file
+  rc = trexio_read_nucleus_num(file, &num);
+  assert (rc == TREXIO_SUCCESS);
+  assert (num == 12);
+
+  // read numerical dataset from the file
+  nucl_index = (int*) calloc(num, sizeof(int));
+  rc = trexio_read_basis_nucleus_index(file, nucl_index);
+  assert (rc == TREXIO_SUCCESS);
+  assert ( nucl_index[num-1] == num );
+
+  free(nucl_index);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_dset (TREXIO_FILE, TEST_BACKEND);
+  test_has_dset   (TREXIO_FILE, TEST_BACKEND);
+  test_read_dset  (TREXIO_FILE, TEST_BACKEND);
+
+  //rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/io_dset_int_text.c

@@ -0,0 +1,134 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_BACKEND 	TREXIO_TEXT
+#define TREXIO_FILE 	"test_dset_i.dir"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to write a dataset with numerical (int) values into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+  int nucl_index[12] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write numerical attribute in an empty file
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+  
+  // write numerical (integer) dataset in a file
+  rc = trexio_write_basis_nucleus_index(file, nucl_index);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a dataset in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file 
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written dataset exists
+  rc = trexio_has_basis_nucleus_index(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that another dataset does not exist
+  rc = trexio_has_mo_coefficient(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to read a dataset with numericali (int) values from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  int num;
+  int* nucl_index;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read numerical attribute from the file
+  rc = trexio_read_nucleus_num(file, &num);
+  assert (rc == TREXIO_SUCCESS);
+  assert (num == 12);
+
+  // read numerical dataset from the file
+  nucl_index = (int*) calloc(num, sizeof(int));
+  rc = trexio_read_basis_nucleus_index(file, nucl_index);
+  assert (rc == TREXIO_SUCCESS);
+  assert ( nucl_index[num-1] == num );
+
+  free(nucl_index);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_dset (TREXIO_FILE, TEST_BACKEND);
+  test_has_dset   (TREXIO_FILE, TEST_BACKEND);
+  test_read_dset  (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/io_dset_str_hdf5.c

@@ -0,0 +1,157 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define TEST_BACKEND 	TREXIO_HDF5
+#define TREXIO_FILE 	"test_dset_s.h5"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_dset_str (const char* file_name, const back_end_t backend) {
+
+/* Try to write an array of strings into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+  const char* labels[] = {"C"       ,
+                          "Na FAKE" ,
+                          "C"       ,
+                          "C"       ,
+                          "C"       ,
+                          "C"       ,
+                          "H"       ,
+                          "H"       ,
+                          "H"       ,
+                          "H"       ,
+                          "H"       ,
+                          "H FAKE"  };
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write numerical attribute in an empty file
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+  
+  // write dataset of string in the file (including FAKE statements)
+  int max_str_len = 16;
+  rc = trexio_write_nucleus_label(file, labels, max_str_len);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_dset_str (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a dataset of strings in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written dataset of strings exists
+  rc = trexio_has_nucleus_label(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that the dataset of strings does not exist
+  rc = trexio_has_mo_symmetry(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_dset_str (const char* file_name, const back_end_t backend) {
+
+/* Try to read a dataset with strings from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  int num;
+  char** labels;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read numerical attribute from the file
+  rc = trexio_read_nucleus_num(file, &num);
+  assert (rc == TREXIO_SUCCESS);
+  assert (num == 12);
+
+  // read the arrays of strings truncated to max_str_len=2 symbols
+  int max_str_len = 2;
+
+  labels = (char**) malloc(num*sizeof(char*));
+  for (int i=0; i<num; i++){
+    labels[i] = (char*) malloc((max_str_len+1)*sizeof(char));
+  }
+
+  rc = trexio_read_nucleus_label(file, labels, max_str_len);
+  assert (rc == TREXIO_SUCCESS);
+  assert (strcmp(labels[0], "C")  == 0);
+  assert (strcmp(labels[1], "Na") == 0);
+
+  for (int i=0; i<num; i++){
+    free(labels[i]);
+  }
+  free(labels);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_dset_str (TREXIO_FILE, TEST_BACKEND);
+  test_has_dset_str   (TREXIO_FILE, TEST_BACKEND);
+  test_read_dset_str  (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/io_dset_str_text.c

@@ -0,0 +1,157 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define TEST_BACKEND 	TREXIO_TEXT
+#define TREXIO_FILE 	"test_dset_s.dir"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_dset_str (const char* file_name, const back_end_t backend) {
+
+/* Try to write an array of strings into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+  const char* labels[] = {"C"       ,
+                          "Na FAKE" ,
+                          "C"       ,
+                          "C"       ,
+                          "C"       ,
+                          "C"       ,
+                          "H"       ,
+                          "H"       ,
+                          "H"       ,
+                          "H"       ,
+                          "H"       ,
+                          "H FAKE"  };
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write numerical attribute in an empty file
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+  
+  // write dataset of string in the file (including FAKE statements)
+  int max_str_len = 16;
+  rc = trexio_write_nucleus_label(file, labels, max_str_len);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_dset_str (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a dataset of strings in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written dataset of strings exists
+  rc = trexio_has_nucleus_label(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that the dataset of strings does not exist
+  rc = trexio_has_mo_symmetry(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_dset_str (const char* file_name, const back_end_t backend) {
+
+/* Try to read a dataset with strings from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  int num;
+  char **labels;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read numerical attribute from the file
+  rc = trexio_read_nucleus_num(file, &num);
+  assert (rc == TREXIO_SUCCESS);
+  assert (num == 12);
+
+  // read the arrays of strings truncated to max_str_len=2 symbols
+  int max_str_len = 2;
+
+  labels = (char**) malloc(num*sizeof(char*));
+  for (int i=0; i<num; i++){
+    labels[i] = (char*) malloc((max_str_len+1)*sizeof(char));
+  }
+
+  rc = trexio_read_nucleus_label(file, labels, max_str_len);
+  assert (rc == TREXIO_SUCCESS);
+  assert (strcmp(labels[0], "C")  == 0);
+  assert (strcmp(labels[1], "Na") == 0);
+
+  for (int i=0; i<num; i++){
+    free(labels[i]);
+  }
+  free(labels);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_dset_str (TREXIO_FILE, TEST_BACKEND);
+  test_has_dset_str   (TREXIO_FILE, TEST_BACKEND);
+  test_read_dset_str  (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/io_num_hdf5.c

@@ -0,0 +1,120 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_BACKEND 	TREXIO_HDF5
+#define TREXIO_FILE 	"test_num.h5"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_num (const char* file_name, const back_end_t backend) {
+
+/* Try to write a dimensioning attribute (num variable) into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write numerical attribute in an empty file
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_num (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a dimensioning attribute (num variable) in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written num variable exists
+  rc = trexio_has_nucleus_num(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that the num variable does not exist
+  rc = trexio_has_mo_num(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_num (const char* file_name, const back_end_t backend) {
+
+/* Try to read a dimensioning attribute (num variable) from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  int num;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read numerical attribute from the file
+  rc = trexio_read_nucleus_num(file, &num);
+  assert (rc == TREXIO_SUCCESS);
+  assert (num == 12);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_num (TREXIO_FILE, TEST_BACKEND);
+  test_has_num   (TREXIO_FILE, TEST_BACKEND);
+  test_read_num  (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/io_num_text.c

@@ -0,0 +1,120 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_BACKEND 	TREXIO_TEXT
+#define TREXIO_FILE 	"test_num.dir"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_num (const char* file_name, const back_end_t backend) {
+
+/* Try to write a dimensioning attribute (num variable) into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write numerical attribute in an empty file
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_num (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a dimensioning attribute (num variable) in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written num variable exists
+  rc = trexio_has_nucleus_num(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that the num variable does not exist
+  rc = trexio_has_mo_num(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_num (const char* file_name, const back_end_t backend) {
+
+/* Try to read a dimensioning attribute (num variable) from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  int num;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read numerical attribute from the file
+  rc = trexio_read_nucleus_num(file, &num);
+  assert (rc == TREXIO_SUCCESS);
+  assert (num == 12);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_num (TREXIO_FILE, TEST_BACKEND);
+  test_has_num   (TREXIO_FILE, TEST_BACKEND);
+  test_read_num  (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/io_str_hdf5.c

@@ -0,0 +1,133 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define TEST_BACKEND 	TREXIO_HDF5
+#define TREXIO_FILE 	"test_str.h5"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_str (const char* file_name, const back_end_t backend) {
+
+/* Try to write a string attribute (single variable-length string) into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  const char* sym = "B3U with some comments";
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write string attribute in an empty file
+  int max_str_len = 32;
+  rc = trexio_write_nucleus_point_group(file, sym, max_str_len);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_str (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a string attribute in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written string attribute exists
+  rc = trexio_has_nucleus_point_group(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that another string attribute does not exist
+  rc = trexio_has_mo_type(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_str (const char* file_name, const back_end_t backend) {
+
+/* Try to read a string attribute from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  char* sym;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read string attribute from the file
+  int max_str_len = 32;
+  sym = (char*) malloc(max_str_len*sizeof(char));
+
+  rc = trexio_read_nucleus_point_group(file, sym, max_str_len);
+  assert (rc == TREXIO_SUCCESS);
+
+  char * pch;
+  pch = strtok(sym, " ");
+  assert (strcmp(pch, "B3U") == 0);
+  /* alternative test when 3 symbols are read from the file to sym */
+  /*rc = trexio_read_nucleus_point_group(file, sym, 3);
+  assert (rc == TREXIO_SUCCESS);
+  assert (strcmp(sym, "B3U") == 0 );*/
+  free(sym);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_str (TREXIO_FILE, TEST_BACKEND);
+  test_has_str   (TREXIO_FILE, TEST_BACKEND);
+  test_read_str  (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/io_str_text.c

@@ -0,0 +1,133 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define TEST_BACKEND 	TREXIO_TEXT
+#define TREXIO_FILE 	"test_str.dir"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_str (const char* file_name, const back_end_t backend) {
+
+/* Try to write a string attribute (single variable-length string) into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  const char* sym = "B3U with some comments";
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write string attribute in an empty file
+  int max_str_len = 32;
+  rc = trexio_write_nucleus_point_group(file, sym, max_str_len);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_str (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a string attribute in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written string attribute exists
+  rc = trexio_has_nucleus_point_group(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that another string attribute does not exist
+  rc = trexio_has_mo_type(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_str (const char* file_name, const back_end_t backend) {
+
+/* Try to read a string attribute from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  char* sym;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read string attribute from the file
+  int max_str_len = 32;
+  sym = (char*) malloc(max_str_len*sizeof(char));
+
+  rc = trexio_read_nucleus_point_group(file, sym, max_str_len);
+  assert (rc == TREXIO_SUCCESS);
+
+  char * pch;
+  pch = strtok(sym, " ");
+  assert (strcmp(pch, "B3U") == 0);
+  /* alternative test when 3 symbols are read from the file to sym */
+  /*rc = trexio_read_nucleus_point_group(file, sym, 3);
+  assert (rc == TREXIO_SUCCESS);
+  assert (strcmp(sym, "B3U") == 0 );*/
+  free(sym);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_str (TREXIO_FILE, TEST_BACKEND);
+  test_has_str   (TREXIO_FILE, TEST_BACKEND);
+  test_read_str  (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/open_hdf5.c

@@ -0,0 +1,95 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_BACKEND 	TREXIO_HDF5
+#define TREXIO_FILE 	"test_open.h5"
+#define TREXIO_VOID 	"non_existing_" TREXIO_FILE
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+
+static int test_open_w (const char* file_name, const back_end_t backend) {
+
+/* Try to open the TREXIO file in 'write' mode */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_open_r (const char* file_name, const back_end_t backend) {
+
+/* Try to open the TREXIO file in 'read' mode */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_open_void (const char* file_name, const back_end_t backend) {
+
+/* Try to open the non-existing TREXIO file in 'read' mode */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file == NULL);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_open_w     (TREXIO_FILE, TEST_BACKEND);
+  test_open_r     (TREXIO_FILE, TEST_BACKEND);
+  test_open_void  (TREXIO_VOID, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/open_text.c

@@ -0,0 +1,95 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_BACKEND 	TREXIO_TEXT
+#define TREXIO_FILE 	"test_open.dir"
+#define TREXIO_VOID 	"non_existing_" TREXIO_FILE
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+
+static int test_open_w (const char* file_name, const back_end_t backend) {
+
+/* Try to open the TREXIO file in 'write' mode */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_open_r (const char* file_name, const back_end_t backend) {
+
+/* Try to open the TREXIO file in 'read' mode */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_open_void (const char* file_name, const back_end_t backend) {
+
+/* Try to open the non-existing TREXIO file in 'read' mode */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file == NULL);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_open_w     (TREXIO_FILE, TEST_BACKEND);
+  test_open_r     (TREXIO_FILE, TEST_BACKEND);
+  test_open_void  (TREXIO_VOID, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/overwrite_all_hdf5.c

@@ -0,0 +1,141 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_BACKEND 	TREXIO_HDF5
+#define TREXIO_FILE 	"test_over.h5"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write (const char* file_name, const back_end_t backend) {
+
+/* Try to write a full set of data (num+dset_num+str+dset_str) related to benzene molecule into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+  double coord[36] = {
+  0.00000000 ,  1.39250319 ,  0.00000000 ,
+ -1.20594314 ,  0.69625160 ,  0.00000000 ,
+ -1.20594314 , -0.69625160 ,  0.00000000 ,
+  0.00000000 , -1.39250319 ,  0.00000000 ,
+  1.20594314 , -0.69625160 ,  0.00000000 ,
+  1.20594314 ,  0.69625160 ,  0.00000000 ,
+ -2.14171677 ,  1.23652075 ,  0.00000000 ,
+ -2.14171677 , -1.23652075 ,  0.00000000 ,
+  0.00000000 , -2.47304151 ,  0.00000000 ,
+  2.14171677 , -1.23652075 ,  0.00000000 ,
+  2.14171677 ,  1.23652075 ,  0.00000000 ,
+  0.00000000 ,  2.47304151 ,  0.00000000 ,
+  };
+  const char* sym = "D6h";
+  const char* labels[] = {"C" ,
+                          "C" ,
+                          "C" ,
+                          "C" ,
+                          "C" ,
+                          "C" ,
+                          "H" ,
+                          "H" ,
+                          "H" ,
+                          "H" ,
+                          "H" ,
+                          "H" };
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write the data
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+
+  rc = trexio_write_nucleus_coord(file, coord);
+  assert (rc == TREXIO_SUCCESS);
+  
+  rc = trexio_write_nucleus_point_group(file, sym, 4);
+  assert (rc == TREXIO_SUCCESS);
+  
+  rc = trexio_write_nucleus_label(file, labels, 2);
+  assert (rc == TREXIO_SUCCESS);
+  
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_overwrite (const char* file_name, const back_end_t backend) {
+
+/* Try to overwrite the data that already exists in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 24;
+  double coord[3] = {
+  0.00000000 ,  666.666,  0.00000000 ,
+  };
+  const char* sym = "Unknown";
+  const char* labels[] = {"Ru" ,
+                          "U"  ,
+                          "Cl" ,
+                          "Na" ,
+                          "H" };
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // check that the previously written data cannot be overwritten
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_ATTR_ALREADY_EXISTS);
+
+  rc = trexio_write_nucleus_coord(file, coord);
+  assert (rc == TREXIO_DSET_ALREADY_EXISTS);
+  
+  rc = trexio_write_nucleus_point_group(file, sym, 16);
+  assert (rc == TREXIO_ATTR_ALREADY_EXISTS);
+  
+  rc = trexio_write_nucleus_label(file, labels, 4);
+  assert (rc == TREXIO_DSET_ALREADY_EXISTS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write     (TREXIO_FILE, TEST_BACKEND);
+  test_overwrite (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/overwrite_all_text.c

@@ -0,0 +1,141 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_BACKEND 	TREXIO_TEXT
+#define TREXIO_FILE 	"test_over.dir"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write (const char* file_name, const back_end_t backend) {
+
+/* Try to write a full set of data (num+dset_num+str+dset_str) related to benzene molecule into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+  double coord[36] = {
+  0.00000000 ,  1.39250319 ,  0.00000000 ,
+ -1.20594314 ,  0.69625160 ,  0.00000000 ,
+ -1.20594314 , -0.69625160 ,  0.00000000 ,
+  0.00000000 , -1.39250319 ,  0.00000000 ,
+  1.20594314 , -0.69625160 ,  0.00000000 ,
+  1.20594314 ,  0.69625160 ,  0.00000000 ,
+ -2.14171677 ,  1.23652075 ,  0.00000000 ,
+ -2.14171677 , -1.23652075 ,  0.00000000 ,
+  0.00000000 , -2.47304151 ,  0.00000000 ,
+  2.14171677 , -1.23652075 ,  0.00000000 ,
+  2.14171677 ,  1.23652075 ,  0.00000000 ,
+  0.00000000 ,  2.47304151 ,  0.00000000 ,
+  };
+  const char* sym = "D6h";
+  const char* labels[] = {"C" ,
+                          "C" ,
+                          "C" ,
+                          "C" ,
+                          "C" ,
+                          "C" ,
+                          "H" ,
+                          "H" ,
+                          "H" ,
+                          "H" ,
+                          "H" ,
+                          "H" };
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write the data
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+
+  rc = trexio_write_nucleus_coord(file, coord);
+  assert (rc == TREXIO_SUCCESS);
+  
+  rc = trexio_write_nucleus_point_group(file, sym, 4);
+  assert (rc == TREXIO_SUCCESS);
+  
+  rc = trexio_write_nucleus_label(file, labels, 2);
+  assert (rc == TREXIO_SUCCESS);
+  
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_overwrite (const char* file_name, const back_end_t backend) {
+
+/* Try to overwrite the data that already exists in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 24;
+  double coord[3] = {
+  0.00000000 ,  666.666,  0.00000000 ,
+  };
+  const char* sym = "Unknown";
+  const char* labels[] = {"Ru" ,
+                          "U"  ,
+                          "Cl" ,
+                          "Na" ,
+                          "H" };
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // check that the previously written data cannot be overwritten
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_ATTR_ALREADY_EXISTS);
+
+  rc = trexio_write_nucleus_coord(file, coord);
+  assert (rc == TREXIO_DSET_ALREADY_EXISTS);
+  
+  rc = trexio_write_nucleus_point_group(file, sym, 16);
+  assert (rc == TREXIO_ATTR_ALREADY_EXISTS);
+  
+  rc = trexio_write_nucleus_label(file, labels, 4);
+  assert (rc == TREXIO_DSET_ALREADY_EXISTS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write     (TREXIO_FILE, TEST_BACKEND);
+  test_overwrite (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+