gh-102837: more tests for the math module (GH-111930)

Add tests to improve coverage:

* fsum: L1369, L1379, L1383, L1412
* trunc: L2081
* log: L2267
* dist: L2577, L2579
* hypot: L2632
* sumprod: L2744, L2754, L2774, L2778, L2781, L2785, L2831, L2835, L2838
* pow: L2982
* prod: L3294, L3308, L3318-3330

// line numbers wrt to 9dc4fb8

Author: skirpichev

Lib/test/test_math.py

@@ -685,6 +685,7 @@ def msum(iterable):
             ([], 0.0),
             ([0.0], 0.0),
             ([1e100, 1.0, -1e100, 1e-100, 1e50, -1.0, -1e50], 1e-100),
+            ([1e100, 1.0, -1e100, 1e-100, 1e50, -1, -1e50], 1e-100),
             ([2.0**53, -0.5, -2.0**-54], 2.0**53-1.0),
             ([2.0**53, 1.0, 2.0**-100], 2.0**53+2.0),
             ([2.0**53+10.0, 1.0, 2.0**-100], 2.0**53+12.0),
@@ -733,9 +734,20 @@ def msum(iterable):
             self.assertEqual(msum(vals), math.fsum(vals))
 
         self.assertEqual(math.fsum([1.0, math.inf]), math.inf)
+        self.assertTrue(math.isnan(math.fsum([math.nan, 1.0])))
+        self.assertEqual(math.fsum([1e100, FloatLike(1.0), -1e100, 1e-100,
+                                    1e50, FloatLike(-1.0), -1e50]), 1e-100)
         self.assertRaises(OverflowError, math.fsum, [1e+308, 1e+308])
         self.assertRaises(ValueError, math.fsum, [math.inf, -math.inf])
         self.assertRaises(TypeError, math.fsum, ['spam'])
+        self.assertRaises(TypeError, math.fsum, 1)
+        self.assertRaises(OverflowError, math.fsum, [10**1000])
+
+        def bad_iter():
+            yield 1.0
+            raise ZeroDivisionError
+
+        self.assertRaises(ZeroDivisionError, math.fsum, bad_iter())
 
     def testGcd(self):
         gcd = math.gcd
@@ -797,6 +809,8 @@ def testHypot(self):
         # Test allowable types (those with __float__)
         self.assertEqual(hypot(12.0, 5.0), 13.0)
         self.assertEqual(hypot(12, 5), 13)
+        self.assertEqual(hypot(1, -1), math.sqrt(2))
+        self.assertEqual(hypot(1, FloatLike(-1.)), math.sqrt(2))
         self.assertEqual(hypot(Decimal(12), Decimal(5)), 13)
         self.assertEqual(hypot(Fraction(12, 32), Fraction(5, 32)), Fraction(13, 32))
         self.assertEqual(hypot(bool(1), bool(0), bool(1), bool(1)), math.sqrt(3))
@@ -948,6 +962,10 @@ def testDist(self):
         # Test allowable types (those with __float__)
         self.assertEqual(dist((14.0, 1.0), (2.0, -4.0)), 13.0)
         self.assertEqual(dist((14, 1), (2, -4)), 13)
+        self.assertEqual(dist((FloatLike(14.), 1), (2, -4)), 13)
+        self.assertEqual(dist((11, 1), (FloatLike(-1.), -4)), 13)
+        self.assertEqual(dist((14, FloatLike(-1.)), (2, -6)), 13)
+        self.assertEqual(dist((14, -1), (2, -6)), 13)
         self.assertEqual(dist((D(14), D(1)), (D(2), D(-4))), D(13))
         self.assertEqual(dist((F(14, 32), F(1, 32)), (F(2, 32), F(-4, 32))),
                          F(13, 32))
@@ -1005,6 +1023,12 @@ class T(tuple):
         with self.assertRaises(TypeError):
             dist([1], 2)
 
+        class BadFloat:
+            __float__ = BadDescr()
+
+        with self.assertRaises(ValueError):
+            dist([1], [BadFloat()])
+
         # Verify that the one dimensional case is equivalent to abs()
         for i in range(20):
             p, q = random.random(), random.random()
@@ -1175,6 +1199,7 @@ def testLdexp(self):
 
     def testLog(self):
         self.assertRaises(TypeError, math.log)
+        self.assertRaises(TypeError, math.log, 1, 2, 3)
         self.ftest('log(1/e)', math.log(1/math.e), -1)
         self.ftest('log(1)', math.log(1), 0)
         self.ftest('log(e)', math.log(math.e), 1)
@@ -1245,6 +1270,8 @@ def testSumProd(self):
         self.assertEqual(sumprod(iter([10, 20, 30]), (1, 2, 3)), 140)
         self.assertEqual(sumprod([1.5, 2.5], [3.5, 4.5]), 16.5)
         self.assertEqual(sumprod([], []), 0)
+        self.assertEqual(sumprod([-1], [1.]), -1)
+        self.assertEqual(sumprod([1.], [-1]), -1)
 
         # Type preservation and coercion
         for v in [
@@ -1270,11 +1297,20 @@ def testSumProd(self):
         self.assertRaises(TypeError, sumprod, [], [], [])   # Three args
         self.assertRaises(TypeError, sumprod, None, [10])   # Non-iterable
         self.assertRaises(TypeError, sumprod, [10], None)   # Non-iterable
+        self.assertRaises(TypeError, sumprod, ['x'], [1.0])
 
         # Uneven lengths
         self.assertRaises(ValueError, sumprod, [10, 20], [30])
         self.assertRaises(ValueError, sumprod, [10], [20, 30])
 
+        # Overflows
+        self.assertEqual(sumprod([10**20], [1]), 10**20)
+        self.assertEqual(sumprod([1], [10**20]), 10**20)
+        self.assertEqual(sumprod([10**10], [10**10]), 10**20)
+        self.assertEqual(sumprod([10**7]*10**5, [10**7]*10**5), 10**19)
+        self.assertRaises(OverflowError, sumprod, [10**1000], [1.0])
+        self.assertRaises(OverflowError, sumprod, [1.0], [10**1000])
+
         # Error in iterator
         def raise_after(n):
             for i in range(n):
@@ -1285,6 +1321,11 @@ def raise_after(n):
         with self.assertRaises(RuntimeError):
             sumprod(raise_after(5), range(10))
 
+        from test.test_iter import BasicIterClass
+
+        self.assertEqual(sumprod(BasicIterClass(1), [1]), 0)
+        self.assertEqual(sumprod([1], BasicIterClass(1)), 0)
+
         # Error in multiplication
         class BadMultiply:
             def __mul__(self, other):
@@ -1524,6 +1565,7 @@ def testPow(self):
         self.assertTrue(math.isnan(math.pow(2, NAN)))
         self.assertTrue(math.isnan(math.pow(0, NAN)))
         self.assertEqual(math.pow(1, NAN), 1)
+        self.assertRaises(OverflowError, math.pow, 1e+100, 1e+100)
 
         # pow(0., x)
         self.assertEqual(math.pow(0., INF), 0.)
@@ -1880,6 +1922,8 @@ def __trunc__(self):
                 return 23
         class TestNoTrunc:
             pass
+        class TestBadTrunc:
+            __trunc__ = BadDescr()
 
         self.assertEqual(math.trunc(TestTrunc()), 23)
         self.assertEqual(math.trunc(FloatTrunc()), 23)
@@ -1888,6 +1932,7 @@ class TestNoTrunc:
         self.assertRaises(TypeError, math.trunc, 1, 2)
         self.assertRaises(TypeError, math.trunc, FloatLike(23.5))
         self.assertRaises(TypeError, math.trunc, TestNoTrunc())
+        self.assertRaises(ValueError, math.trunc, TestBadTrunc())
 
     def testIsfinite(self):
         self.assertTrue(math.isfinite(0.0))
@@ -2088,6 +2133,8 @@ def test_mtestfile(self):
                       '\n  '.join(failures))
 
     def test_prod(self):
+        from fractions import Fraction as F
+
         prod = math.prod
         self.assertEqual(prod([]), 1)
         self.assertEqual(prod([], start=5), 5)
@@ -2099,6 +2146,14 @@ def test_prod(self):
         self.assertEqual(prod([1.0, 2.0, 3.0, 4.0, 5.0]), 120.0)
         self.assertEqual(prod([1, 2, 3, 4.0, 5.0]), 120.0)
         self.assertEqual(prod([1.0, 2.0, 3.0, 4, 5]), 120.0)
+        self.assertEqual(prod([1., F(3, 2)]), 1.5)
+
+        # Error in multiplication
+        class BadMultiply:
+            def __rmul__(self, other):
+                raise RuntimeError
+        with self.assertRaises(RuntimeError):
+            prod([10., BadMultiply()])
 
         # Test overflow in fast-path for integers
         self.assertEqual(prod([1, 1, 2**32, 1, 1]), 2**32)