Fix inspection of built-in functions with >= 3.11

sebastinas · sebastinas · commit 917382530f0d · 2022-10-26T19:56:36.000+02:00
The built-in functions no longer have their signature in the docstring,
but now inspect.signature can produce results. But as we have no source
for built-in functions, we cannot replace the default values. Hence, we
handle built-in functions in an extra step.

This commit also changes the handling of default values slightly. They
are now always put into a _Repr.
diff --git a/bpython/inspection.py b/bpython/inspection.py
@@ -57,9 +57,9 @@ class ArgSpec:
     args: List[str]
     varargs: Optional[str]
     varkwargs: Optional[str]
-    defaults: Optional[List[Any]]
+    defaults: Optional[List[_Repr]]
     kwonly: List[str]
-    kwonly_defaults: Optional[Dict[str, Any]]
+    kwonly_defaults: Optional[Dict[str, _Repr]]
     annotations: Optional[Dict[str, Any]]
 
 
@@ -169,31 +169,51 @@ def parsekeywordpairs(signature: str) -> Dict[str, str]:
     return {item[0]: "".join(item[2:]) for item in stack if len(item) >= 3}
 
 
-def _fixlongargs(f: Callable, argspec: ArgSpec) -> ArgSpec:
+def _fix_default_values(f: Callable, argspec: ArgSpec) -> ArgSpec:
     """Functions taking default arguments that are references to other objects
-    whose str() is too big will cause breakage, so we swap out the object
-    itself with the name it was referenced with in the source by parsing the
-    source itself !"""
-    if argspec.defaults is None:
+    will cause breakage, so we swap out the object itself with the name it was
+    referenced with in the source by parsing the source itself!"""
+
+    if argspec.defaults is None and argspec.kwonly_defaults is None:
         # No keyword args, no need to do anything
         return argspec
-    values = list(argspec.defaults)
-    if not values:
-        return argspec
-    keys = argspec.args[-len(values) :]
+
     try:
-        src = inspect.getsourcelines(f)
+        src, _ = inspect.getsourcelines(f)
     except (OSError, IndexError):
         # IndexError is raised in inspect.findsource(), can happen in
         # some situations. See issue #94.
         return argspec
-    kwparsed = parsekeywordpairs("".join(src[0]))
+    except TypeError:
+        # No source code is available (for Python >= 3.11)
+        #
+        # If the function is a builtin, we replace the default values.
+        # Otherwise, let's bail out.
+        if not inspect.isbuiltin(f):
+            raise
+
+        if argspec.defaults is not None:
+            argspec.defaults = [_Repr(str(value)) for value in argspec.defaults]
+        if argspec.kwonly_defaults is not None:
+            argspec.kwonly_defaults = {
+                key: _Repr(str(value))
+                for key, value in argspec.kwonly_defaults.items()
+            }
+        return argspec
 
-    for i, (key, value) in enumerate(zip(keys, values)):
-        if len(repr(value)) != len(kwparsed[key]):
+    kwparsed = parsekeywordpairs("".join(src))
+
+    if argspec.defaults is not None:
+        values = list(argspec.defaults)
+        keys = argspec.args[-len(values) :]
+        for i, key in enumerate(keys):
             values[i] = _Repr(kwparsed[key])
 
-    argspec.defaults = values
+        argspec.defaults = values
+    if argspec.kwonly_defaults is not None:
+        for key in argspec.kwonly_defaults.keys():
+            argspec.kwonly_defaults[key] = _Repr(kwparsed[key])
+
     return argspec
 
 
@@ -234,11 +254,11 @@ def _getpydocspec(f: Callable) -> Optional[ArgSpec]:
             if varargs is not None:
                 kwonly_args.append(arg)
                 if default:
-                    kwonly_defaults[arg] = default
+                    kwonly_defaults[arg] = _Repr(default)
             else:
                 args.append(arg)
                 if default:
-                    defaults.append(default)
+                    defaults.append(_Repr(default))
 
     return ArgSpec(
         args, varargs, varkwargs, defaults, kwonly_args, kwonly_defaults, None
@@ -267,7 +287,9 @@ def getfuncprops(func: str, f: Callable) -> Optional[FuncProps]:
         return None
     try:
         argspec = _get_argspec_from_signature(f)
-        fprops = FuncProps(func, _fixlongargs(f, argspec), is_bound_method)
+        fprops = FuncProps(
+            func, _fix_default_values(f, argspec), is_bound_method
+        )
     except (TypeError, KeyError, ValueError):
         argspec_pydoc = _getpydocspec(f)
         if argspec_pydoc is None:
diff --git a/bpython/test/test_inspection.py b/bpython/test/test_inspection.py
@@ -11,6 +11,7 @@
 from bpython.test.fodder import encoding_utf8
 
 pypy = "PyPy" in sys.version
+_is_py311 = sys.version_info[:2] >= (3, 11)
 
 try:
     import numpy
@@ -53,38 +54,32 @@ def test_parsekeywordpairs(self):
         def fails(spam=["-a", "-b"]):
             pass
 
-        default_arg_repr = "['-a', '-b']"
-        self.assertEqual(
-            str(["-a", "-b"]),
-            default_arg_repr,
-            "This test is broken (repr does not match), fix me.",
-        )
-
         argspec = inspection.getfuncprops("fails", fails)
+        self.assertIsNotNone(argspec)
         defaults = argspec.argspec.defaults
-        self.assertEqual(str(defaults[0]), default_arg_repr)
+        self.assertEqual(str(defaults[0]), '["-a", "-b"]')
 
     def test_pasekeywordpairs_string(self):
         def spam(eggs="foo, bar"):
             pass
 
         defaults = inspection.getfuncprops("spam", spam).argspec.defaults
-        self.assertEqual(repr(defaults[0]), "'foo, bar'")
+        self.assertEqual(repr(defaults[0]), '"foo, bar"')
 
     def test_parsekeywordpairs_multiple_keywords(self):
         def spam(eggs=23, foobar="yay"):
             pass
 
         defaults = inspection.getfuncprops("spam", spam).argspec.defaults
         self.assertEqual(repr(defaults[0]), "23")
-        self.assertEqual(repr(defaults[1]), "'yay'")
+        self.assertEqual(repr(defaults[1]), '"yay"')
 
     def test_pasekeywordpairs_annotation(self):
         def spam(eggs: str = "foo, bar"):
             pass
 
         defaults = inspection.getfuncprops("spam", spam).argspec.defaults
-        self.assertEqual(repr(defaults[0]), "'foo, bar'")
+        self.assertEqual(repr(defaults[0]), '"foo, bar"')
 
     def test_get_encoding_ascii(self):
         self.assertEqual(inspection.get_encoding(encoding_ascii), "ascii")
@@ -134,8 +129,15 @@ def test_getfuncprops_print(self):
         self.assertIn("file", props.argspec.kwonly)
         self.assertIn("flush", props.argspec.kwonly)
         self.assertIn("sep", props.argspec.kwonly)
-        self.assertEqual(props.argspec.kwonly_defaults["file"], "sys.stdout")
-        self.assertEqual(props.argspec.kwonly_defaults["flush"], "False")
+        if _is_py311:
+            self.assertEqual(
+                repr(props.argspec.kwonly_defaults["file"]), "None"
+            )
+        else:
+            self.assertEqual(
+                repr(props.argspec.kwonly_defaults["file"]), "sys.stdout"
+            )
+        self.assertEqual(repr(props.argspec.kwonly_defaults["flush"]), "False")
 
     @unittest.skipUnless(
         numpy is not None and numpy.__version__ >= "1.18",
@@ -173,12 +175,12 @@ def fun_annotations(number: int, lst: List[int] = []) -> List[int]:
         props = inspection.getfuncprops("fun", fun)
         self.assertEqual(props.func, "fun")
         self.assertEqual(props.argspec.args, ["number", "lst"])
-        self.assertEqual(props.argspec.defaults[0], [])
+        self.assertEqual(repr(props.argspec.defaults[0]), "[]")
 
         props = inspection.getfuncprops("fun_annotations", fun_annotations)
         self.assertEqual(props.func, "fun_annotations")
         self.assertEqual(props.argspec.args, ["number", "lst"])
-        self.assertEqual(props.argspec.defaults[0], [])
+        self.assertEqual(repr(props.argspec.defaults[0]), "[]")
 
     def test_issue_966_class_method(self):
         class Issue966(Sequence):
@@ -215,7 +217,7 @@ def bmethod(cls, number, lst):
         )
         self.assertEqual(props.func, "cmethod")
         self.assertEqual(props.argspec.args, ["number", "lst"])
-        self.assertEqual(props.argspec.defaults[0], [])
+        self.assertEqual(repr(props.argspec.defaults[0]), "[]")
 
     def test_issue_966_static_method(self):
         class Issue966(Sequence):
@@ -252,7 +254,7 @@ def bmethod(number, lst):
         )
         self.assertEqual(props.func, "cmethod")
         self.assertEqual(props.argspec.args, ["number", "lst"])
-        self.assertEqual(props.argspec.defaults[0], [])
+        self.assertEqual(repr(props.argspec.defaults[0]), "[]")
 
 
 class A:
