Debug tests

tdms/tests/unit/benchmark_scripts/create_hdf5_test_file.py

@@ -16,12 +16,11 @@ def create_hdf5_test_file() -> None:
         os.mkdir(os.path.dirname(FNAME_TO_CREATE))
     file = h5py.File(FNAME_TO_CREATE, "w")
 
-    # Create a group under root
-    read_in_test = file.require_group("read_in_test")
-
     # Create test data to read in
     consecutive_numbers = np.arange(0, 12, dtype=float)
 
+    # Create a group under root
+    read_in_test = file.require_group("read_in_test")
     # Populate group with test data
     read_in_test.create_dataset(
         "vector_int", data=consecutive_numbers, shape=(12,), dtype=int
@@ -33,6 +32,19 @@ def create_hdf5_test_file() -> None:
         "tensor_double", data=consecutive_numbers, shape=(2, 3, 2), dtype=float
     )
 
+    # Create & populate the group that mimics MATLAB empty arrays
+    # Deliberately include some data here to stress that emptiness is based off the presence of an attribute
+    flag_as_empty = file.require_group("flag_as_empty")
+    flag_as_empty.attrs["MATLAB_empty"] = np.array(1, dtype=np.uint8)
+    flag_as_empty.create_dataset(
+        "consecutive_numbers", data=consecutive_numbers[0:3], shape=(3,), dtype=float
+    )
+
+    # Create a top-level dataset that will be empty, but the absence of the MATLAB_empty attribute will not mark it as so
+    file.create_dataset(
+        "not_marked_empty", data=consecutive_numbers[0:0], shape=(0,), dtype=float
+    )
+
     file.attrs["file_attribute"] = 1
 
     file.close()

tdms/tests/unit/hdf5_io_tests/test_hdf5_base.cpp

@@ -1,4 +1,5 @@
 #include <catch2/catch_test_macros.hpp>
+#include <spdlog/spdlog.h>
 
 #include "hdf5_io/hdf5_reader.h"
 #include "unit_test_utils.h"
@@ -8,7 +9,9 @@ using tdms_unit_test_data::struct_testdata;
 
 // HDF5Base cannot be instantiated, so we use HDF5Reader just to avoid
 // accidental writes.
-TEST_CASE("HDF5Base: is_empty()") {
+TEST_CASE("HDF5Base: has_MATLAB_empty()") {
+  spdlog::info("HDF5Base::has_MATLAB_empty()");
+
   HDF5Reader matlab_file(struct_testdata);
   HDF5Reader hdf5_file(hdf5_test_file);
 
@@ -24,7 +27,7 @@ TEST_CASE("HDF5Base: is_empty()") {
     REQUIRE(!matlab_file.has_MATLAB_empty("nonempty_dataset"));
     // Point to nonempty group (struct)
     REQUIRE(!matlab_file.has_MATLAB_empty("example_struct"));
-    // Point to nonempty dataset not created by MATLAB (so the attribute should
+    // Point to nonempty group not created by MATLAB (so the attribute should
     // not be flagged)
     REQUIRE(!hdf5_file.has_MATLAB_empty("read_in_test"));
   }
@@ -40,4 +43,11 @@ TEST_CASE("HDF5Base: is_empty()") {
     REQUIRE_THROWS_AS(hdf5_file.has_MATLAB_empty("file_attribute"),
                       std::runtime_error);
   }
+
+  SECTION("False positives") {
+    // Object has an attribute MATLAB_empty, but still contains data
+    REQUIRE(hdf5_file.has_MATLAB_empty("flag_as_empty"));
+    // Object is an empty array, but does not have the MATLAB_empty flag
+    REQUIRE(!hdf5_file.has_MATLAB_empty("not_marked_empty"));
+  }
 }