Issue #18365: Add mock Text class and test thereof versus tk.Text.

Based on patches by Todd.Rovito and Phil Webster.

Lib/idlelib/idle_test/test_text.py

+# Test mock_tk.Text class against tkinter.Text class by running same tests with both.
+import unittest
+from test.support import requires
+
+from _tkinter import TclError
+import tkinter as tk
+
+class TextTest(object):
+
+    hw = 'hello\nworld'  # usual initial insert after initialization
+    hwn = hw+'\n'  # \n present at initialization, before insert
+
+    Text = None
+    def setUp(self):
+        self.text = self.Text()
+
+    def test_init(self):
+        self.assertEqual(self.text.get('1.0'), '\n')
+        self.assertEqual(self.text.get('end'), '')
+
+    def test_index_empty(self):
+        index = self.text.index
+
+        for dex in (-1.0, 0.3, '1.-1', '1.0', '1.0 lineend', '1.end', '1.33',
+                'insert'):
+            self.assertEqual(index(dex), '1.0')
+
+        for dex in 'end', 2.0, '2.1', '33.44':
+            self.assertEqual(index(dex), '2.0')
+
+    def test_index_data(self):
+        index = self.text.index
+        self.text.insert('1.0', self.hw)
+
+        for dex in -1.0, 0.3, '1.-1', '1.0':
+            self.assertEqual(index(dex), '1.0')
+
+        for dex in '1.0 lineend', '1.end', '1.33':
+             self.assertEqual(index(dex), '1.5')
+
+        for dex in 'end',  '33.44':
+            self.assertEqual(index(dex), '3.0')
+
+    def test_get(self):
+        get = self.text.get
+        Equal = self.assertEqual
+        self.text.insert('1.0', self.hw)
+
+        Equal(get('end'), '')
+        Equal(get('end', 'end'), '')
+        Equal(get('1.0'), 'h')
+        Equal(get('1.0', '1.1'), 'h')
+        Equal(get('1.0', '1.3'), 'hel')
+        Equal(get('1.1', '1.3'), 'el')
+        Equal(get('1.0', '1.0 lineend'), 'hello')
+        Equal(get('1.0', '1.10'), 'hello')
+        Equal(get('1.0 lineend'), '\n')
+        Equal(get('1.1', '2.3'), 'ello\nwor')
+        Equal(get('1.0', '2.5'), self.hw)
+        Equal(get('1.0', 'end'), self.hwn)
+        Equal(get('0.0', '5.0'), self.hwn)
+
+    def test_insert(self):
+        insert = self.text.insert
+        get = self.text.get
+        Equal = self.assertEqual
+
+        insert('1.0', self.hw)
+        Equal(get('1.0', 'end'), self.hwn)
+
+        insert('1.0', '')  # nothing
+        Equal(get('1.0', 'end'), self.hwn)
+
+        insert('1.0', '*')
+        Equal(get('1.0', 'end'), '*hello\nworld\n')
+
+        insert('1.0 lineend', '*')
+        Equal(get('1.0', 'end'), '*hello*\nworld\n')
+
+        insert('2.3', '*')
+        Equal(get('1.0', 'end'), '*hello*\nwor*ld\n')
+
+        insert('end', 'x')
+        Equal(get('1.0', 'end'), '*hello*\nwor*ldx\n')
+
+        insert('1.4', 'x\n')
+        Equal(get('1.0', 'end'), '*helx\nlo*\nwor*ldx\n')
+
+    def test_no_delete(self):
+        # if index1 == 'insert' or 'end' or >= end, there is no deletion
+        delete = self.text.delete
+        get = self.text.get
+        Equal = self.assertEqual
+        self.text.insert('1.0', self.hw)
+
+        delete('insert')
+        Equal(get('1.0', 'end'), self.hwn)
+
+        delete('end')
+        Equal(get('1.0', 'end'), self.hwn)
+
+        delete('insert', 'end')
+        Equal(get('1.0', 'end'), self.hwn)
+
+        delete('insert', '5.5')
+        Equal(get('1.0', 'end'), self.hwn)
+
+        delete('1.4', '1.0')
+        Equal(get('1.0', 'end'), self.hwn)
+
+        delete('1.4', '1.4')
+        Equal(get('1.0', 'end'), self.hwn)
+
+    def test_delete_char(self):
+        delete = self.text.delete
+        get = self.text.get
+        Equal = self.assertEqual
+        self.text.insert('1.0', self.hw)
+
+        delete('1.0')
+        Equal(get('1.0', '1.end'), 'ello')
+
+        delete('1.0', '1.1')
+        Equal(get('1.0', '1.end'), 'llo')
+
+        # delete \n and combine 2 lines into 1
+        delete('1.end')
+        Equal(get('1.0', '1.end'), 'lloworld')
+
+        self.text.insert('1.3', '\n')
+        delete('1.10')
+        Equal(get('1.0', '1.end'), 'lloworld')
+
+        self.text.insert('1.3', '\n')
+        delete('1.3', '2.0')
+        Equal(get('1.0', '1.end'), 'lloworld')
+
+    def test_delete_slice(self):
+        delete = self.text.delete
+        get = self.text.get
+        Equal = self.assertEqual
+        self.text.insert('1.0', self.hw)
+
+        delete('1.0', '1.0 lineend')
+        Equal(get('1.0', 'end'), '\nworld\n')
+
+        delete('1.0', 'end')
+        Equal(get('1.0', 'end'), '\n')
+
+        self.text.insert('1.0', self.hw)
+        delete('1.0', '2.0')
+        Equal(get('1.0', 'end'), 'world\n')
+
+        delete('1.0', 'end')
+        Equal(get('1.0', 'end'), '\n')
+
+        self.text.insert('1.0', self.hw)
+        delete('1.2', '2.3')
+        Equal(get('1.0', 'end'), 'held\n')
+
+    def test_multiple_lines(self):  # insert and delete
+        self.text.insert('1.0', 'hello')
+
+        self.text.insert('1.3', '1\n2\n3\n4\n5')
+        self.assertEqual(self.text.get('1.0', 'end'), 'hel1\n2\n3\n4\n5lo\n')
+
+        self.text.delete('1.3', '5.1')
+        self.assertEqual(self.text.get('1.0', 'end'), 'hello\n')
+
+    def test_compare(self):
+        compare = self.text.compare
+        Equal = self.assertEqual
+        # need data so indexes not squished to 1,0
+        self.text.insert('1.0', 'First\nSecond\nThird\n')
+
+        self.assertRaises(TclError, compare, '2.2', 'op', '2.2')
+
+        for op, less1, less0, equal, greater0, greater1 in (
+                ('<', True, True, False, False, False),
+                ('<=', True, True, True, False, False),
+                ('>', False, False, False, True, True),
+                ('>=', False, False, True, True, True),
+                ('==', False, False, True, False, False),
+                ('!=', True, True, False, True, True),
+                ):
+            Equal(compare('1.1', op, '2.2'), less1, op)
+            Equal(compare('2.1', op, '2.2'), less0, op)
+            Equal(compare('2.2', op, '2.2'), equal, op)
+            Equal(compare('2.3', op, '2.2'), greater0, op)
+            Equal(compare('3.3', op, '2.2'), greater1, op)
+
+
+class MockTextTest(TextTest, unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        from idlelib.idle_test.mock_tk import Text
+        cls.Text = Text
+
+    def test_decode(self):
+        # test endflags (-1, 0) not tested by test_index (which uses +1)
+        decode = self.text._decode
+        Equal = self.assertEqual
+        self.text.insert('1.0', self.hw)
+
+        Equal(decode('end', -1), (2, 5))
+        Equal(decode('3.1', -1), (2, 5))
+        Equal(decode('end',  0), (2, 6))
+        Equal(decode('3.1', 0), (2, 6))
+
+
+class TkTextTest(TextTest, unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        requires('gui')
+        from tkinter import Tk, Text
+        cls.Text = Text
+        cls.root = Tk()
+
+    @classmethod
+    def tearDownClass(cls):
+        cls.root.destroy()
+
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2, exit=False)
+