[3.12] gh-111495: Add tests for PyComplex C API (GH-111591) (GH-111753)

(cherry picked from commit 24b5cbd3dce3fe37cdc787ccedd1e73a4f8cfc3c)

Co-authored-by: Sergey B Kirpichev <skirpichev@gmail.com>

2 files changed, 238 insertions, 0 deletions

diff --git a/Lib/test/test_capi/test_complex.py b/Lib/test/test_capi/test_complex.py
new file mode 100644
index 0000000..9f51efb
--- /dev/null
+++ b/Lib/test/test_capi/test_complex.py
@@ -0,0 +1,146 @@
+import unittest
+import warnings
+
+from test.test_capi.test_getargs import (BadComplex, BadComplex2, Complex,
+                                         FloatSubclass, Float, BadFloat,
+                                         BadFloat2, ComplexSubclass)
+from test.support import import_helper
+
+
+_testcapi = import_helper.import_module('_testcapi')
+
+NULL = None
+
+class BadComplex3:
+    def __complex__(self):
+        raise RuntimeError
+
+
+class CAPIComplexTest(unittest.TestCase):
+    def test_check(self):
+        # Test PyComplex_Check()
+        check = _testcapi.complex_check
+
+        self.assertTrue(check(1+2j))
+        self.assertTrue(check(ComplexSubclass(1+2j)))
+        self.assertFalse(check(Complex()))
+        self.assertFalse(check(3))
+        self.assertFalse(check(3.0))
+        self.assertFalse(check(object()))
+
+        # CRASHES check(NULL)
+
+    def test_checkexact(self):
+        # PyComplex_CheckExact()
+        checkexact = _testcapi.complex_checkexact
+
+        self.assertTrue(checkexact(1+2j))
+        self.assertFalse(checkexact(ComplexSubclass(1+2j)))
+        self.assertFalse(checkexact(Complex()))
+        self.assertFalse(checkexact(3))
+        self.assertFalse(checkexact(3.0))
+        self.assertFalse(checkexact(object()))
+
+        # CRASHES checkexact(NULL)
+
+    def test_fromccomplex(self):
+        # Test PyComplex_FromCComplex()
+        fromccomplex = _testcapi.complex_fromccomplex
+
+        self.assertEqual(fromccomplex(1+2j), 1.0+2.0j)
+
+    def test_fromdoubles(self):
+        # Test PyComplex_FromDoubles()
+        fromdoubles = _testcapi.complex_fromdoubles
+
+        self.assertEqual(fromdoubles(1.0, 2.0), 1.0+2.0j)
+
+    def test_realasdouble(self):
+        # Test PyComplex_RealAsDouble()
+        realasdouble = _testcapi.complex_realasdouble
+
+        self.assertEqual(realasdouble(1+2j), 1.0)
+        self.assertEqual(realasdouble(-1+0j), -1.0)
+        self.assertEqual(realasdouble(4.25), 4.25)
+        self.assertEqual(realasdouble(-1.0), -1.0)
+        self.assertEqual(realasdouble(42), 42.)
+        self.assertEqual(realasdouble(-1), -1.0)
+
+        # Test subclasses of complex/float
+        self.assertEqual(realasdouble(ComplexSubclass(1+2j)), 1.0)
+        self.assertEqual(realasdouble(FloatSubclass(4.25)), 4.25)
+
+        # Test types with __complex__ dunder method
+        # Function doesn't support classes with __complex__ dunder, see #109598
+        self.assertRaises(TypeError, realasdouble, Complex())
+
+        # Test types with __float__ dunder method
+        self.assertEqual(realasdouble(Float()), 4.25)
+        self.assertRaises(TypeError, realasdouble, BadFloat())
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(realasdouble(BadFloat2()), 4.25)
+
+        self.assertRaises(TypeError, realasdouble, object())
+
+        # CRASHES realasdouble(NULL)
+
+    def test_imagasdouble(self):
+        # Test PyComplex_ImagAsDouble()
+        imagasdouble = _testcapi.complex_imagasdouble
+
+        self.assertEqual(imagasdouble(1+2j), 2.0)
+        self.assertEqual(imagasdouble(1-1j), -1.0)
+        self.assertEqual(imagasdouble(4.25), 0.0)
+        self.assertEqual(imagasdouble(42), 0.0)
+
+        # Test subclasses of complex/float
+        self.assertEqual(imagasdouble(ComplexSubclass(1+2j)), 2.0)
+        self.assertEqual(imagasdouble(FloatSubclass(4.25)), 0.0)
+
+        # Test types with __complex__ dunder method
+        # Function doesn't support classes with __complex__ dunder, see #109598
+        self.assertEqual(imagasdouble(Complex()), 0.0)
+
+        # Function returns 0.0 anyway, see #109598
+        self.assertEqual(imagasdouble(object()), 0.0)
+
+        # CRASHES imagasdouble(NULL)
+
+    def test_asccomplex(self):
+        # Test PyComplex_AsCComplex()
+        asccomplex = _testcapi.complex_asccomplex
+
+        self.assertEqual(asccomplex(1+2j), 1.0+2.0j)
+        self.assertEqual(asccomplex(-1+2j), -1.0+2.0j)
+        self.assertEqual(asccomplex(4.25), 4.25+0.0j)
+        self.assertEqual(asccomplex(-1.0), -1.0+0.0j)
+        self.assertEqual(asccomplex(42), 42+0j)
+        self.assertEqual(asccomplex(-1), -1.0+0.0j)
+
+        # Test subclasses of complex/float
+        self.assertEqual(asccomplex(ComplexSubclass(1+2j)), 1.0+2.0j)
+        self.assertEqual(asccomplex(FloatSubclass(4.25)), 4.25+0.0j)
+
+        # Test types with __complex__ dunder method
+        self.assertEqual(asccomplex(Complex()), 4.25+0.5j)
+        self.assertRaises(TypeError, asccomplex, BadComplex())
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(asccomplex(BadComplex2()), 4.25+0.5j)
+        with warnings.catch_warnings():
+            warnings.simplefilter("error", DeprecationWarning)
+            self.assertRaises(DeprecationWarning, asccomplex, BadComplex2())
+        self.assertRaises(RuntimeError, asccomplex, BadComplex3())
+
+        # Test types with __float__ dunder method
+        self.assertEqual(asccomplex(Float()), 4.25+0.0j)
+        self.assertRaises(TypeError, asccomplex, BadFloat())
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(asccomplex(BadFloat2()), 4.25+0.0j)
+
+        self.assertRaises(TypeError, asccomplex, object())
+
+        # CRASHES asccomplex(NULL)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Modules/_testcapi/complex.c b/Modules/_testcapi/complex.c
index 0402b8e..400f405 100644
--- a/Modules/_testcapi/complex.c
+++ b/Modules/_testcapi/complex.c
@@ -1,7 +1,99 @@
 #include "parts.h"
 #include "util.h"
 
+
+static PyObject *
+complex_check(PyObject *Py_UNUSED(module), PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyLong_FromLong(PyComplex_Check(obj));
+}
+
+static PyObject *
+complex_checkexact(PyObject *Py_UNUSED(module), PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyLong_FromLong(PyComplex_CheckExact(obj));
+}
+
+static PyObject *
+complex_fromccomplex(PyObject *Py_UNUSED(module), PyObject *obj)
+{
+    Py_complex complex;
+
+    if (!PyArg_Parse(obj, "D", &complex)) {
+        return NULL;
+    }
+
+    return PyComplex_FromCComplex(complex);
+}
+
+static PyObject *
+complex_fromdoubles(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    double real, imag;
+
+    if (!PyArg_ParseTuple(args, "dd", &real, &imag)) {
+        return NULL;
+    }
+
+    return PyComplex_FromDoubles(real, imag);
+}
+
+static PyObject *
+complex_realasdouble(PyObject *Py_UNUSED(module), PyObject *obj)
+{
+    double real;
+
+    NULLABLE(obj);
+    real = PyComplex_RealAsDouble(obj);
+
+    if (real == -1. && PyErr_Occurred()) {
+        return NULL;
+    }
+
+    return PyFloat_FromDouble(real);
+}
+
+static PyObject *
+complex_imagasdouble(PyObject *Py_UNUSED(module), PyObject *obj)
+{
+    double imag;
+
+    NULLABLE(obj);
+    imag = PyComplex_ImagAsDouble(obj);
+
+    if (imag == -1. && PyErr_Occurred()) {
+        return NULL;
+    }
+
+    return PyFloat_FromDouble(imag);
+}
+
+static PyObject *
+complex_asccomplex(PyObject *Py_UNUSED(module), PyObject *obj)
+{
+    Py_complex complex;
+
+    NULLABLE(obj);
+    complex = PyComplex_AsCComplex(obj);
+
+    if (complex.real == -1. && PyErr_Occurred()) {
+        return NULL;
+    }
+
+    return PyComplex_FromCComplex(complex);
+}
+
+
 static PyMethodDef test_methods[] = {
+    {"complex_check", complex_check, METH_O},
+    {"complex_checkexact", complex_checkexact, METH_O},
+    {"complex_fromccomplex", complex_fromccomplex, METH_O},
+    {"complex_fromdoubles", complex_fromdoubles, METH_VARARGS},
+    {"complex_realasdouble", complex_realasdouble, METH_O},
+    {"complex_imagasdouble", complex_imagasdouble, METH_O},
+    {"complex_asccomplex", complex_asccomplex, METH_O},
     {NULL},
 };