Add tests for workbench.util.io

qt/applications/workbench/workbench/utils/test/test_io.py

+# Mantid Repository : https://github.com/mantidproject/mantid
+#
+# Copyright © 2021 ISIS Rutherford Appleton Laboratory UKRI,
+#   NScD Oak Ridge National Laboratory, European Spallation Source,
+#   Institut Laue - Langevin & CSNS, Institute of High Energy Physics, CAS
+# SPDX - License - Identifier: GPL - 3.0 +
+#  This file is part of the mantidworkbench package
+from unittest import TestCase
+from unittest.mock import patch
+
+from PyQt5.QtWidgets import QInputDialog
+from workbench.utils.io import input_qinputdialog
+
+
+class IOTest(TestCase):
+
+    @patch('workbench.utils.io.QInputDialog')
+    def test_input_qinputdialog_setup_is_correct(self, mock_QInputDialogClass):
+        mock_QInputDialogClass.TextInput = QInputDialog.TextInput
+        mock_QInputDialog = mock_QInputDialogClass()
+
+        _ = input_qinputdialog("prompt")
+
+        mock_QInputDialog.setInputMode.assert_called_with(QInputDialog.TextInput)
+        mock_QInputDialog.setLabelText.assert_called_with("prompt")
+
+    @patch('workbench.utils.io.QInputDialog')
+    def test_input_qinputdialog_return_value_is_correct_when_dialog_accepted(self, mock_QInputDialogClass):
+        mock_QInputDialog = mock_QInputDialogClass()
+        mock_QInputDialog.exec_.return_value = True
+        mock_QInputDialog.textValue.return_value = "their input"
+
+        user_input = input_qinputdialog()
+
+        self.assertEqual(user_input, "their input")
+
+    @patch('workbench.utils.io.QInputDialog')
+    def test_input_qinputdialog_raises_RuntimeError_when_input_cancelled(self, mock_QInputDialogClass):
+        mock_QInputDialog = mock_QInputDialogClass()
+        mock_QInputDialog.exec_.return_value = False
+
+        self.assertRaises(RuntimeError, input_qinputdialog)
+