Merge pull request #229 from honno/remaining-fft-tests

Remaining FFT tests

array_api_tests/test_fft.py

@@ -291,8 +291,26 @@ def test_ihfft(x, data):
     assert_n_axis_shape("ihfft", x=x, n=n, axis=axis, out=out, size_gt_1=True)
 
 
-# TODO:
-# fftfreq
-# rfftfreq
-# fftshift
-# ifftshift
+@given( n=st.integers(1, 100), kw=hh.kwargs(d=st.floats(0.1, 5)))
+def test_fftfreq(n, kw):
+    out = xp.fft.fftfreq(n, **kw)
+    ph.assert_shape("fftfreq", out_shape=out.shape, expected=(n,), kw={"n": n})
+
+
+@given(n=st.integers(1, 100), kw=hh.kwargs(d=st.floats(0.1, 5)))
+def test_rfftfreq(n, kw):
+    out = xp.fft.rfftfreq(n, **kw)
+    ph.assert_shape("rfftfreq", out_shape=out.shape, expected=(n // 2 + 1,), kw={"n": n})
+
+
+@pytest.mark.parametrize("func_name", ["fftshift", "ifftshift"])
+@given(x=hh.arrays(xps.floating_dtypes(), fft_shapes_strat), data=st.data())
+def test_shift_func(func_name, x, data):
+    func = getattr(xp.fft, func_name)
+    axes = data.draw(
+        st.none() | st.lists(st.sampled_from(list(range(x.ndim))), min_size=1, unique=True),
+        label="axes",
+    )
+    out = func(x, axes=axes)
+    ph.assert_dtype(func_name, in_dtype=x.dtype, out_dtype=out.dtype)
+    ph.assert_shape(func_name, out_shape=out.shape, expected=x.shape)