gh-111495: Add tests for PyFloat C API (GH-111624)

Lib/test/test_capi/test_float.py

@@ -0,0 +1,117 @@
+import math
+import sys
+import unittest
+import warnings
+
+from test.test_capi.test_getargs import (Float, FloatSubclass, FloatSubclass2,
+                                         BadIndex2, BadFloat2, Index, BadIndex,
+                                         BadFloat)
+from test.support import import_helper
+
+_testcapi = import_helper.import_module('_testcapi')
+
+NULL = None
+
+
+class CAPIFloatTest(unittest.TestCase):
+    def test_check(self):
+        # Test PyFloat_Check()
+        check = _testcapi.float_check
+
+        self.assertTrue(check(4.25))
+        self.assertTrue(check(FloatSubclass(4.25)))
+        self.assertFalse(check(Float()))
+        self.assertFalse(check(3))
+        self.assertFalse(check(object()))
+
+        # CRASHES check(NULL)
+
+    def test_checkexact(self):
+        # Test PyFloat_CheckExact()
+        checkexact = _testcapi.float_checkexact
+
+        self.assertTrue(checkexact(4.25))
+        self.assertFalse(checkexact(FloatSubclass(4.25)))
+        self.assertFalse(checkexact(Float()))
+        self.assertFalse(checkexact(3))
+        self.assertFalse(checkexact(object()))
+
+        # CRASHES checkexact(NULL)
+
+    def test_fromstring(self):
+        # Test PyFloat_FromString()
+        fromstring = _testcapi.float_fromstring
+
+        self.assertEqual(fromstring("4.25"), 4.25)
+        self.assertEqual(fromstring(b"4.25"), 4.25)
+        self.assertRaises(ValueError, fromstring, "4.25\0")
+        self.assertRaises(ValueError, fromstring, b"4.25\0")
+
+        self.assertEqual(fromstring(bytearray(b"4.25")), 4.25)
+
+        self.assertEqual(fromstring(memoryview(b"4.25")), 4.25)
+        self.assertEqual(fromstring(memoryview(b"4.255")[:-1]), 4.25)
+        self.assertRaises(TypeError, fromstring, memoryview(b"4.25")[::2])
+
+        self.assertRaises(TypeError, fromstring, 4.25)
+
+        # CRASHES fromstring(NULL)
+
+    def test_fromdouble(self):
+        # Test PyFloat_FromDouble()
+        fromdouble = _testcapi.float_fromdouble
+
+        self.assertEqual(fromdouble(4.25), 4.25)
+
+    def test_asdouble(self):
+        # Test PyFloat_AsDouble()
+        asdouble = _testcapi.float_asdouble
+
+        class BadFloat3:
+            def __float__(self):
+                raise RuntimeError
+
+        self.assertEqual(asdouble(4.25), 4.25)
+        self.assertEqual(asdouble(-1.0), -1.0)
+        self.assertEqual(asdouble(42), 42.0)
+        self.assertEqual(asdouble(-1), -1.0)
+        self.assertEqual(asdouble(2**1000), float(2**1000))
+
+        self.assertEqual(asdouble(FloatSubclass(4.25)), 4.25)
+        self.assertEqual(asdouble(FloatSubclass2(4.25)), 4.25)
+        self.assertEqual(asdouble(Index()), 99.)
+
+        self.assertRaises(TypeError, asdouble, BadIndex())
+        self.assertRaises(TypeError, asdouble, BadFloat())
+        self.assertRaises(RuntimeError, asdouble, BadFloat3())
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(asdouble(BadIndex2()), 1.)
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(asdouble(BadFloat2()), 4.25)
+        with warnings.catch_warnings():
+            warnings.simplefilter("error", DeprecationWarning)
+            self.assertRaises(DeprecationWarning, asdouble, BadFloat2())
+        self.assertRaises(TypeError, asdouble, object())
+        self.assertRaises(TypeError, asdouble, NULL)
+
+    def test_getinfo(self):
+        # Test PyFloat_GetInfo()
+        getinfo = _testcapi.float_getinfo
+
+        self.assertEqual(getinfo(), sys.float_info)
+
+    def test_getmax(self):
+        # Test PyFloat_GetMax()
+        getmax = _testcapi.float_getmax
+
+        self.assertEqual(getmax(), sys.float_info.max)
+
+    def test_getmin(self):
+        # Test PyFloat_GetMax()
+        getmin = _testcapi.float_getmin
+
+        self.assertEqual(getmin(), sys.float_info.min)
+
+
+if __name__ == "__main__":
+    unittest.main()