Add more tests to cover different use cases

Author: antonwolfy

tests/test_mathematical.py

@@ -1897,6 +1897,93 @@ def test_wrong_tol_type(self, xp, tol_val):
         assert_raises(TypeError, xp.real_if_close, a, tol=tol_val)
 
 
+class TestSinc:
+    @pytest.mark.parametrize(
+        "dt", get_all_dtypes(no_none=True, no_bool=True, no_float16=False)
+    )
+    def test_basic(self, dt):
+        a = numpy.linspace(-1, 1, 100, dtype=dt)
+        ia = dpnp.array(a)
+
+        result = dpnp.sinc(ia)
+        expected = numpy.sinc(a)
+        assert_dtype_allclose(result, expected)
+
+    def test_bool(self):
+        a = numpy.array([True, False, True])
+        ia = dpnp.array(a)
+
+        result = dpnp.sinc(ia)
+        expected = numpy.sinc(a)
+        # numpy 1.26 promotes result to float64 dtype, but expected float16
+        assert_dtype_allclose(
+            result,
+            expected,
+            check_only_type_kind=(
+                numpy.lib.NumpyVersion(numpy.__version__) < "2.0.0"
+            ),
+        )
+
+    @pytest.mark.parametrize("dt", get_all_dtypes(no_none=True, no_bool=True))
+    def test_zero(self, dt):
+        if (
+            dt == numpy.float16
+            and numpy.lib.NumpyVersion(numpy.__version__) < "2.0.0"
+        ):
+            pytest.skip("numpy.sinc return NaN")
+
+        a = numpy.array([0.0], dtype=dt)
+        ia = dpnp.array(a)
+
+        result = dpnp.sinc(ia)
+        expected = numpy.sinc(a)
+        assert_dtype_allclose(result, expected)
+
+    @testing.with_requires("numpy>=2.0.0")
+    def test_zero_fp16(self):
+        a = numpy.array([0.0], dtype=numpy.float16)
+        ia = dpnp.array(a)
+
+        result = dpnp.sinc(ia)
+        expected = numpy.sinc(a)
+        assert_dtype_allclose(result, expected)
+
+    @pytest.mark.usefixtures("suppress_invalid_numpy_warnings")
+    def test_nan_infs(self):
+        a = numpy.array([numpy.inf, -numpy.inf, numpy.nan])
+        ia = dpnp.array(a)
+
+        result = dpnp.sinc(ia)
+        expected = numpy.sinc(a)
+        assert_equal(result, expected)
+
+    @pytest.mark.usefixtures("suppress_invalid_numpy_warnings")
+    def test_nan_infs_complex(self):
+        a = numpy.array(
+            [
+                numpy.inf,
+                -numpy.inf,
+                numpy.nan,
+                complex(numpy.nan),
+                complex(numpy.nan, numpy.nan),
+                complex(0, numpy.nan),
+                complex(numpy.inf, numpy.nan),
+                complex(numpy.nan, numpy.inf),
+                complex(-numpy.inf, numpy.nan),
+                complex(numpy.nan, -numpy.inf),
+                complex(numpy.inf, numpy.inf),
+                complex(numpy.inf, -numpy.inf),
+                complex(-numpy.inf, numpy.inf),
+                complex(-numpy.inf, -numpy.inf),
+            ]
+        )
+        ia = dpnp.array(a)
+
+        result = dpnp.sinc(ia)
+        expected = numpy.sinc(a)
+        assert_equal(result, expected)
+
+
 class TestTrapezoid:
     def get_numpy_func(self):
         if numpy.lib.NumpyVersion(numpy.__version__) < "2.0.0":