Backported tests for Tkinter variables.

Lib/lib-tk/test/test_tkinter/test_variables.py

+import unittest
+
+from Tkinter import Variable, StringVar, IntVar, DoubleVar, BooleanVar, Tk, TclError
+
+
+class TestBase(unittest.TestCase):
+
+    def setUp(self):
+        self.root = Tk()
+
+    def tearDown(self):
+        self.root.destroy()
+
+
+class TestVariable(TestBase):
+
+    def info_exists(self, *args):
+        return self.root.getboolean(self.root.call("info", "exists", *args))
+
+    def test_default(self):
+        v = Variable(self.root)
+        self.assertEqual("", v.get())
+        self.assertRegexpMatches(str(v), r"^PY_VAR(\d+)$")
+
+    def test_name_and_value(self):
+        v = Variable(self.root, "sample string", "varname")
+        self.assertEqual("sample string", v.get())
+        self.assertEqual("varname", str(v))
+
+    def test___del__(self):
+        self.assertFalse(self.info_exists("varname"))
+        v = Variable(self.root, "sample string", "varname")
+        self.assertTrue(self.info_exists("varname"))
+        del v
+        self.assertFalse(self.info_exists("varname"))
+
+    def test_dont_unset_not_existing(self):
+        self.assertFalse(self.info_exists("varname"))
+        v1 = Variable(self.root, name="name")
+        v2 = Variable(self.root, name="name")
+        del v1
+        self.assertFalse(self.info_exists("name"))
+        # shouldn't raise exception
+        del v2
+        self.assertFalse(self.info_exists("name"))
+
+    def test___eq__(self):
+        # values doesn't matter, only class and name are checked
+        v1 = Variable(self.root, name="abc")
+        v2 = Variable(self.root, name="abc")
+        self.assertEqual(v1, v2)
+
+        v3 = Variable(self.root, name="abc")
+        v4 = StringVar(self.root, name="abc")
+        self.assertNotEqual(v3, v4)
+
+    def test_invalid_name(self):
+        with self.assertRaises(TypeError):
+            Variable(self.root, name=123)
+
+
+class TestStringVar(TestBase):
+
+    def test_default(self):
+        v = StringVar(self.root)
+        self.assertEqual("", v.get())
+
+    def test_get(self):
+        v = StringVar(self.root, "abc", "name")
+        self.assertEqual("abc", v.get())
+        self.root.globalsetvar("name", "value")
+        self.assertEqual("value", v.get())
+
+
+class TestIntVar(TestBase):
+
+    def test_default(self):
+        v = IntVar(self.root)
+        self.assertEqual(0, v.get())
+
+    def test_get(self):
+        v = IntVar(self.root, 123, "name")
+        self.assertEqual(123, v.get())
+        self.root.globalsetvar("name", "345")
+        self.assertEqual(345, v.get())
+
+    def test_invalid_value(self):
+        v = IntVar(self.root, name="name")
+        self.root.globalsetvar("name", "value")
+        with self.assertRaises(ValueError):
+            v.get()
+        self.root.globalsetvar("name", "345.0")
+        with self.assertRaises(ValueError):
+            v.get()
+
+
+class TestDoubleVar(TestBase):
+
+    def test_default(self):
+        v = DoubleVar(self.root)
+        self.assertEqual(0.0, v.get())
+
+    def test_get(self):
+        v = DoubleVar(self.root, 1.23, "name")
+        self.assertAlmostEqual(1.23, v.get())
+        self.root.globalsetvar("name", "3.45")
+        self.assertAlmostEqual(3.45, v.get())
+
+    def test_get_from_int(self):
+        v = DoubleVar(self.root, 1.23, "name")
+        self.assertAlmostEqual(1.23, v.get())
+        self.root.globalsetvar("name", "3.45")
+        self.assertAlmostEqual(3.45, v.get())
+        self.root.globalsetvar("name", "456")
+        self.assertAlmostEqual(456, v.get())
+
+    def test_invalid_value(self):
+        v = DoubleVar(self.root, name="name")
+        self.root.globalsetvar("name", "value")
+        with self.assertRaises(ValueError):
+            v.get()
+
+
+class TestBooleanVar(TestBase):
+
+    def test_default(self):
+        v = BooleanVar(self.root)
+        self.assertEqual(False, v.get())
+
+    def test_get(self):
+        v = BooleanVar(self.root, True, "name")
+        self.assertAlmostEqual(True, v.get())
+        self.root.globalsetvar("name", "0")
+        self.assertAlmostEqual(False, v.get())
+
+    def test_invalid_value_domain(self):
+        v = BooleanVar(self.root, name="name")
+        self.root.globalsetvar("name", "value")
+        with self.assertRaises(TclError):
+            v.get()
+        self.root.globalsetvar("name", "1.0")
+        with self.assertRaises(TclError):
+            v.get()
+
+
+tests_gui = (TestVariable, TestStringVar, TestIntVar,
+             TestDoubleVar, TestBooleanVar)
+
+
+if __name__ == "__main__":
+    from test.support import run_unittest
+    run_unittest(*tests_gui)

Misc/NEWS

@@ -134,6 +134,8 @@ IDLE
 Tests
 -----
 
+- Backported tests for Tkinter variables.
+
 - Issue #19320: test_tcl no longer fails when wantobjects is false.
 
 - Issue #19683: Removed empty tests from test_minidom.  Initial patch by