#86: (failing) unit test for creating intermediate derivative files

ancpbids/torch.py

@@ -37,5 +37,4 @@ def split(self, *args: float):
         if not math.isclose(sum_ratios, 1.0):
             raise ValueError("sum of split ratios should be 1.0")
 
-        size_dataset = len(self)
-        return random_split(self, [round(size_dataset * ratio) for ratio in args])
+        return random_split(self, args)

tests/auto/test_writing.py

@@ -107,6 +107,35 @@ def test_create_new_dataset(self):
 
         # TODO reload dataset and add assertions
 
+    def test_write_intermediate_results(self):
+        from ancpbids import model_latest as schema
+        dataset = schema.create_dataset(name='my-test-ds')
+        dataset.dataset_description.Name = 'a programmatically created dataset'
+        dataset.dataset_description.BIDSVersion = schema.VERSION
+
+        for i in range(1, 10):
+            subject = dataset.create_folder(name=f"sub-{i}", type_=schema.Subject)
+            func_folder = subject.create_folder(name='func', type_=schema.DatatypeFolder)
+            img_file = func_folder.create_artifact()
+            img_file.suffix = 'bold'
+            img_file.extension = '.nii.gz'
+            img_file.add_entity('task', 'programming')
+            # touch() makes sure the artifact has a proper BIDS name within its parent directory
+            file_path: str = img_file.touch()
+            # we only care about the path beginning with the derivative folder
+            expected_relative_file_path = os.path.normpath(
+                f"my-test-ds/sub-{i}/func/sub-{i}_task-programming_bold.nii.gz")
+            self.assertTrue(file_path.endswith(expected_relative_file_path))
+
+            # we can also get its absolute path name
+            file_path_abs = img_file.get_absolute_path()
+            self.assertEqual(file_path_abs, file_path, "Expected touch to return the absolute path of the file")
+
+            self.assertFalse(os.path.exists(file_path), f"File should not have been created yet: {file_path}")
+            # just create an empty file (this is where users would call some third party lib to create file specific contents)
+            open(file_path, 'w').close()
+            self.assertTrue(os.path.exists(file_path), f"Missing expected file {file_path}")
+
 
 if __name__ == '__main__':
     unittest.main()