👽️ fft[pack]: fix new stubtest errors (#336)

.mypyignore

@@ -1,38 +1,33 @@
 # typecheck-only helper types
 scipy(\.\w+)?\._typing
 
-# git submodules
-scipy\._lib\.(array_api_compat|array_api_extra|cobyqa).*
-
-# private bundled pypocketfft library
-scipy\.fft\._pocketfft\..*
-
 # internal scipy testing code
 scipy\.conftest
 scipy\.((_|\w)+\.)+(__test__|test|tests(\..+)?)
 
+# git submodules and bundled 3rd party libs
+scipy\._lib\.(array_api_compat|array_api_extra|cobyqa).*
+scipy\.fft\._pocketfft\..*
+
+# numpy re-export with wrong annotations on numpy<1.24
+scipy\.fftpack\.(_?helper\.)?fftfreq
+
 # accidental implicit exports of internal scipy machinery
 scipy\._lib\.decorator\.(DEF|ArgSpec|FunctionMaker|__init__|append|dispatch_on|get_init|getargspec|init|n_args)
-scipy\.special\._precompute\..*
+scipy\.special\._precompute\..*  # TODO??
 scipy\.special\.libsf_error_state
-scipy\.stats\._rcont.rcont
+scipy\.stats\._rcont\.rcont
 
 # omitted methods that always return `NotImplemented` or always raise
 scipy\.sparse\._(\w+)\._(\w+)\.__(len|i(add|mul|sub)|(i|r)(true)?div)__
 
 # workarounds for mypy bugs
-scipy\._lib\._array_api\.(Array|ArrayLike)  # these exist, but in `if TYPE_CHECKING: ...`
-scipy\._lib\._ccallback\.PyCFuncPtr  # this exists, but under `if TYPE_CHECKING: ...`
 scipy\.signal\._short_time_fft\.(FFT_MODE_TYPE|PAD_TYPE)  # `Literal[...] != def (*, **)`
 scipy\.(_lib|integrate|stats)\.((_|\w)+\.)+__replace__  # `NamedTuple` on `python >= 3.13`
 
 # stubtest doesn't understand `if sys.version_info >= _: ...` blocks
-scipy\.fftpack\.helper\.fftfreq
 scipy\.sparse\.(\w+)\.warn
 
-# numpy re-export with wrong annotations on numpy<1.24
-scipy\.fftpack\.(_helper\.)?fftfreq
-
 # mypy fails recognize type-check-only ufunc subtypes as ufuncs
 # https://github.com/KotlinIsland/basedmypy/issues/816
 scipy\.special\._basic\.digamma
@@ -88,7 +83,6 @@ scipy.special.dawsn
 scipy.special.wofz
 scipy.special.wrightomega
 scipy.special.zetac
-
 scipy.special.bdtr(c|i(k|n)?)?
 scipy.special.btdtri(a|b)
 scipy.special.chdtr(c|iv?)?

.mypyignore-todo

@@ -1,10 +1,3 @@
-scipy\.fft\._basic_backend\.complex_funcs
-
-scipy\.fftpack\.(_pseudo_diffs\.)?diff
-scipy\.fftpack\.(_pseudo_diffs\.)?shift
-scipy\.fftpack\.(_pseudo_diffs\.)?(c|s){2}_diff
-scipy\.fftpack\.(_pseudo_diffs\.)?(h|t|it)ilbert
-
 scipy\.integrate\.(_quadrature\.)?__all__
 scipy\.integrate\.(_quadrature\.)?AccuracyWarning
 scipy\.integrate\.(_quadrature\.)?(quadrature|romberg|romberg|simpson)

scipy-stubs/_lib/_ccallback.pyi

@@ -1,5 +1,5 @@
 import ctypes as ct
-from _ctypes import CFuncPtr as PyCFuncPtr
+from _ctypes import CFuncPtr as _CFuncPtr
 from types import ModuleType
 from typing import ClassVar, Generic, Literal, NoReturn, Protocol, TypeAlias, final, overload, type_check_only
 from typing_extensions import CapsuleType as PyCapsule, Self, TypeVar, TypeVarTuple, Unpack, override
@@ -104,6 +104,9 @@ ffi: Literal[False] | None
 
 # public api
 
+@final
+class PyCFuncPtr(_CFuncPtr): ...
+
 @final
 class CData: ...
 

scipy-stubs/fft/_basic_backend.pyi

@@ -1,3 +1,5 @@
+from typing import Final
+
 from ._basic import (
     fft as fft,
     fft2 as fft2,
@@ -18,3 +20,5 @@ from ._basic import (
     rfft2 as rfft2,
     rfftn as rfftn,
 )
+
+complex_funcs: Final = {"fft", "ifft", "fftn", "ifftn", "hfft", "irfft", "irfftn"}

scipy-stubs/fftpack/_pseudo_diffs.pyi

@@ -1,3 +1,4 @@
+from _thread import _local as _Cache  # seriously, typeshed?
 from typing import TypeAlias, overload
 
 import numpy as np
@@ -9,8 +10,6 @@ __all__ = ["cc_diff", "cs_diff", "diff", "hilbert", "ihilbert", "itilbert", "sc_
 _Vec_d: TypeAlias = onp.Array1D[np.float64]
 _Vec_dD: TypeAlias = onp.Array1D[np.float64 | np.complex128]
 
-_Cache: TypeAlias = dict[tuple[onp.ToFloat, ...], _Vec_d]  # {n: kernel}
-
 ###
 
 #