Test array object method signatures

Author: honno

array_api_tests/stubs.py

@@ -1,11 +1,12 @@
 import sys
+import inspect
 from importlib import import_module
 from importlib.util import find_spec
 from pathlib import Path
 from types import FunctionType, ModuleType
 from typing import Dict, List
 
-__all__ = ["category_to_funcs", "array", "EXTENSIONS", "extension_to_funcs"]
+__all__ = ["array_methods", "category_to_funcs", "EXTENSIONS", "extension_to_funcs"]
 
 
 spec_dir = Path(__file__).parent.parent / "array-api" / "spec" / "API_specification"
@@ -22,6 +23,12 @@
     name = path.name.replace(".py", "")
     name_to_mod[name] = import_module(f"signatures.{name}")
 
+array = name_to_mod["array_object"].array
+array_methods = [
+    f for n, f in inspect.getmembers(array, predicate=inspect.isfunction)
+    if n != "__init__"  # probably exists for Sphinx
+]
+
 
 category_to_funcs: Dict[str, List[FunctionType]] = {}
 for name, mod in name_to_mod.items():
@@ -31,9 +38,6 @@
         assert all(isinstance(o, FunctionType) for o in objects)
         category_to_funcs[category] = objects
 
-array = name_to_mod["array_object"].array
-
-
 EXTENSIONS: str = ["linalg"]
 extension_to_funcs: Dict[str, List[FunctionType]] = {}
 for ext in EXTENSIONS:

array_api_tests/test_signatures.py

@@ -1,11 +1,14 @@
-from inspect import Parameter, signature
+from inspect import Parameter, Signature, signature
 from types import FunctionType
 from typing import Callable, Dict
 
 import pytest
+from hypothesis import given
 
+from . import hypothesis_helpers as hh
+from . import xps
 from ._array_module import mod as xp
-from .stubs import category_to_funcs, extension_to_funcs
+from .stubs import array_methods, category_to_funcs, extension_to_funcs
 
 kind_to_str: Dict[Parameter, str] = {
     Parameter.POSITIONAL_OR_KEYWORD: "normal argument",
@@ -16,7 +19,9 @@
 }
 
 
-def _test_signature(func: Callable, stub: FunctionType):
+def _test_signature(
+    func: Callable, stub: FunctionType, ignore_first_stub_param: bool = False
+):
     """
     Signature of function is correct enough to not affect interoperability
 
@@ -34,9 +39,16 @@ def add(x1, x2, /):
         pytest.skip(
             msg=f"type({stub.__name__})={type(func)} not supported by inspect.signature()"
         )
-    stub_sig = signature(stub)
     params = list(sig.parameters.values())
+
+    stub_sig = signature(stub)
     stub_params = list(stub_sig.parameters.values())
+    if ignore_first_stub_param:
+        stub_params = stub_params[1:]
+        stub = Signature(
+            parameters=stub_params, return_annotation=stub_sig.return_annotation
+        )
+
     # We're not interested if the array module has additional arguments, so we
     # only iterate through the arguments listed in the spec.
     for i, stub_param in enumerate(stub_params):
@@ -87,7 +99,7 @@ def add(x1, x2, /):
     [s for stubs in category_to_funcs.values() for s in stubs],
     ids=lambda f: f.__name__,
 )
-def test_signature(stub: FunctionType):
+def test_func_signature(stub: FunctionType):
     assert hasattr(xp, stub.__name__), f"{stub.__name__} not found in array module"
     func = getattr(xp, stub.__name__)
     _test_signature(func, stub)
@@ -96,21 +108,26 @@ def test_signature(stub: FunctionType):
 extension_and_stub_params = []
 for ext, stubs in extension_to_funcs.items():
     for stub in stubs:
-        extension_and_stub_params.append(
-            pytest.param(
-                ext,
-                stub,
-                id=f"{ext}.{stub.__name__}",
-                marks=pytest.mark.xp_extension(ext),
-            )
+        p = pytest.param(
+            ext, stub, id=f"{ext}.{stub.__name__}", marks=pytest.mark.xp_extension(ext)
         )
+        extension_and_stub_params.append(p)
 
 
 @pytest.mark.parametrize("extension, stub", extension_and_stub_params)
-def test_extension_signature(extension: str, stub: FunctionType):
+def test_extension_func_signature(extension: str, stub: FunctionType):
     mod = getattr(xp, extension)
     assert hasattr(
         mod, stub.__name__
     ), f"{stub.__name__} not found in {extension} extension"
     func = getattr(mod, stub.__name__)
     _test_signature(func, stub)
+
+
+@pytest.mark.parametrize("stub", array_methods, ids=lambda f: f.__name__)
+@given(x=xps.arrays(dtype=xps.scalar_dtypes(), shape=hh.shapes()))
+def test_array_method_signature(stub: FunctionType, x):
+    assert hasattr(x, stub.__name__), f"{stub.__name__} not found in array object {x!r}"
+    method = getattr(x, stub.__name__)
+    # Ignore 'self' arg in stub, which won't be present in instantiated objects.
+    _test_signature(method, stub, ignore_first_stub_param=True)