[TEST] making tests pass

narps_open/data/task.py

@@ -12,12 +12,14 @@
 class TaskInformation(dict, metaclass=SingletonMeta):
     """ This class allows to access information about the task performed in NARPS """
 
+    task_information_file = join(Configuration()['directories']['dataset'], 'task-MGT_bold.json')
+
     def __init__(self):
         super().__init__()
 
         # Load information from the task-MGT_bold.json file
-        file_name = join(Configuration()['directories']['dataset'], 'task-MGT_bold.json')
-        self.update(load(file))
+        with open(self.task_information_file, 'rb') as file:
+            self.update(load(file))
 
         # Compute derived information
         self['NumberOfSlices'] = len(self['SliceTiming'])

tests/data/test_task.py

@@ -0,0 +1,57 @@
+#!/usr/bin/python
+# coding: utf-8
+
+""" Tests of the 'narps_open.data.task' module.
+
+Launch this test with PyTest
+
+Usage:
+======
+    pytest -q test_task.py
+    pytest -q test_task.py -k <selected_test>
+"""
+from os.path import join
+
+from pytest import mark, fixture
+
+from narps_open.utils.configuration import Configuration
+import narps_open.data.task as task
+
+@fixture(scope='function', autouse=True)
+def mock_task_data(mocker):
+    """ Patch the json.load method to mock task data """
+    mocker.patch.object(
+        task.TaskInformation, 'task_information_file',
+        join(Configuration()['directories']['test_data'], 'data', 'task', 'task-info.json')
+        )
+
+class TestTaskInformation:
+    """ A class that contains all the unit tests for the TaskInformation class."""
+
+    @staticmethod
+    @mark.unit_test
+    def test_accessing():
+        """ Check that task information is reachable """
+
+        assert task.TaskInformation()['RepetitionTime'] == 1
+        assert len(task.TaskInformation()['SliceTiming']) == 6
+
+    @staticmethod
+    @mark.unit_test
+    def test_singleton():
+        """ Check that TaskInformation is a singleton. """
+
+        obj1 = task.TaskInformation()
+        obj2 = task.TaskInformation()
+
+        assert id(obj1) == id(obj2)
+
+    @staticmethod
+    @mark.unit_test
+    def test_derived():
+        """ Test the derived values of a TaskInformation object """
+
+        task_info = task.TaskInformation()
+        assert task_info['NumberOfSlices'] == 6
+        assert task_info['AcquisitionTime'] == 1 / 6
+        assert task_info['TotalReadoutTime'] == 12

tests/test_data/data/task/task-info.json

@@ -0,0 +1,12 @@
+{
+  "RepetitionTime": 1,
+  "EffectiveEchoSpacing": 2,
+  "SliceTiming": [
+    0,
+    0.4375,
+    0.875,
+    0.3125,
+    0.75,
+    0.1875
+  ]
+}