Remove show_none_errors and strict_optional_whitelist (#13507)

These are somewhat buggy and modern per-module options should be
preferred. I can't find any use of strict_optional_whitelist.
There is some use of show_none_errors, but it's all set to True;
I think people are just worried and cargo culting and want mypy to
really, actually give them all the errors.

Fixes #6514, fixes #2396

docs/source/config_file.rst

@@ -574,14 +574,6 @@ Suppressing errors
 Note: these configuration options are available in the config file only. There is
 no analog available via the command line options.
 
-.. confval:: show_none_errors
-
- :type: boolean
- :default: True
-
- Shows errors related to strict ``None`` checking, if the global :confval:`strict_optional`
- flag is enabled.
-
 .. confval:: ignore_errors
 
  :type: boolean

mypy/checker.py

@@ -2,7 +2,6 @@
 
 from __future__ import annotations
 
-import fnmatch
 import itertools
 from collections import defaultdict
 from contextlib import contextmanager, nullcontext
@@ -327,8 +326,6 @@ class TypeChecker(NodeVisitor[None], CheckerPluginInterface):
  current_node_deferred = False
  # Is this file a typeshed stub?
  is_typeshed_stub = False
- # Should strict Optional-related errors be suppressed in this file?
- suppress_none_errors = False # TODO: Get it from options instead
  options: Options
  # Used for collecting inferred attribute types so that they can be checked
  # for consistency.
@@ -391,12 +388,7 @@ def __init__(
  self.is_stub = tree.is_stub
  self.is_typeshed_stub = is_typeshed_file(path)
  self.inferred_attribute_types = None
- if options.strict_optional_whitelist is None:
- self.suppress_none_errors = not options.show_none_errors
- else:
- self.suppress_none_errors = not any(
- fnmatch.fnmatch(path, pattern) for pattern in options.strict_optional_whitelist
- )
+
  # If True, process function definitions. If False, don't. This is used
  # for processing module top levels in fine-grained incremental mode.
  self.recurse_into_functions = True
@@ -5604,8 +5596,6 @@ def check_subtype(
  subtype, supertype, context, msg_text, subtype_label, supertype_label, code=code
  ):
  return False
- if self.should_suppress_optional_error([subtype]):
- return False
  extra_info: list[str] = []
  note_msg = ""
  notes: list[str] = []
@@ -5705,9 +5695,6 @@ def contains_none(self, t: Type) -> bool:
  )
  )
 
- def should_suppress_optional_error(self, related_types: list[Type]) -> bool:
- return self.suppress_none_errors and any(self.contains_none(t) for t in related_types)
-
  def named_type(self, name: str) -> Instance:
  """Return an instance type with given name and implicit Any type args.
 

mypy/checkexpr.py

@@ -2032,8 +2032,6 @@ def check_arg(
  ):
  self.msg.concrete_only_call(callee_type, context)
  elif not is_subtype(caller_type, callee_type, options=self.chk.options):
- if self.chk.should_suppress_optional_error([caller_type, callee_type]):
- return
  code = self.msg.incompatible_argument(
  n,
  m,
@@ -2155,13 +2153,11 @@ def check_overload_call(
  else:
  # There was no plausible match: give up
  target = AnyType(TypeOfAny.from_error)
-
- if not self.chk.should_suppress_optional_error(arg_types):
- if not is_operator_method(callable_name):
- code = None
- else:
- code = codes.OPERATOR
- self.msg.no_variant_matches_arguments(callee, arg_types, context, code=code)
+ if not is_operator_method(callable_name):
+ code = None
+ else:
+ code = codes.OPERATOR
+ self.msg.no_variant_matches_arguments(callee, arg_types, context, code=code)
 
  result = self.check_call(
  target,

mypy/checkmember.py

@@ -232,8 +232,6 @@ def _analyze_member_access(
  elif isinstance(typ, DeletedType):
  mx.msg.deleted_as_rvalue(typ, mx.context)
  return AnyType(TypeOfAny.from_error)
- if mx.chk.should_suppress_optional_error([typ]):
- return AnyType(TypeOfAny.from_error)
  return report_missing_attribute(mx.original_type, typ, name, mx)
 
 
@@ -427,8 +425,6 @@ def analyze_none_member_access(name: str, typ: NoneType, mx: MemberContext) -> T
  ret_type=literal_false,
  fallback=mx.named_type("builtins.function"),
  )
- elif mx.chk.should_suppress_optional_error([typ]):
- return AnyType(TypeOfAny.from_error)
  else:
  return _analyze_member_access(name, mx.named_type("builtins.object"), mx)
 
@@ -545,8 +541,6 @@ def analyze_member_var_access(
  mx.msg.undefined_in_superclass(name, mx.context)
  return AnyType(TypeOfAny.from_error)
  else:
- if mx.chk and mx.chk.should_suppress_optional_error([itype]):
- return AnyType(TypeOfAny.from_error)
  return report_missing_attribute(mx.original_type, itype, name, mx)
 
 

mypy/config_parser.py

@@ -143,7 +143,6 @@ def check_follow_imports(choice: str) -> str:
 # types.
 ini_config_types: Final[dict[str, _INI_PARSER_CALLABLE]] = {
  "python_version": parse_version,
- "strict_optional_whitelist": lambda s: s.split(),
  "custom_typing_module": str,
  "custom_typeshed_dir": expand_path,
  "mypy_path": lambda s: [expand_path(p.strip()) for p in re.split("[,:]", s)],
@@ -172,7 +171,6 @@ def check_follow_imports(choice: str) -> str:
 toml_config_types.update(
  {
  "python_version": parse_version,
- "strict_optional_whitelist": try_split,
  "mypy_path": lambda s: [expand_path(p) for p in try_split(s, "[,:]")],
  "files": lambda s: split_and_match_files_list(try_split(s)),
  "follow_imports": lambda s: check_follow_imports(str(s)),

mypy/main.py

@@ -733,9 +733,6 @@ def add_invertible_flag(
  dest="strict_optional",
  help="Disable strict Optional checks (inverse: --strict-optional)",
  )
- none_group.add_argument(
- "--strict-optional-whitelist", metavar="GLOB", nargs="*", help=argparse.SUPPRESS
- )
 
  lint_group = parser.add_argument_group(
  title="Configuring warnings",
@@ -1268,9 +1265,6 @@ def set_strict_flags() -> None:
  options.disabled_error_codes -= options.enabled_error_codes
 
  # Set build flags.
- if options.strict_optional_whitelist is not None:
- # TODO: Deprecate, then kill this flag
- options.strict_optional = True
  if special_opts.find_occurrences:
  state.find_occurrences = special_opts.find_occurrences.split(".")
  assert state.find_occurrences is not None

mypy/options.py

@@ -47,11 +47,9 @@ class BuildType:
  "local_partial_types",
  "mypyc",
  "no_implicit_optional",
- "show_none_errors",
  "strict_concatenate",
  "strict_equality",
  "strict_optional",
- "strict_optional_whitelist",
  "warn_no_return",
  "warn_return_any",
  "warn_unreachable",
@@ -162,13 +160,6 @@ def __init__(self) -> None:
  self.color_output = True
  self.error_summary = True
 
- # Files in which to allow strict-Optional related errors
- # TODO: Kill this in favor of show_none_errors
- self.strict_optional_whitelist: list[str] | None = None
-
- # Alternate way to show/hide strict-None-checking related errors
- self.show_none_errors = True
-
  # Don't assume arguments with default values of None are Optional
  self.no_implicit_optional = False
 

test-data/unit/check-basic.test

@@ -391,15 +391,6 @@ b = none.__bool__()
 reveal_type(b) # N: Revealed type is "Literal[False]"
 [builtins fixtures/bool.pyi]
 
-[case testNoneHasBoolShowNoneErrorsFalse]
-none = None
-b = none.__bool__()
-reveal_type(b) # N: Revealed type is "Literal[False]"
-[builtins fixtures/bool.pyi]
-[file mypy.ini]
-\[mypy]
-show_none_errors = False
-
 [case testAssignmentInvariantNoteForList]
 from typing import List
 x: List[int]

test-data/unit/check-optional.test

@@ -396,58 +396,6 @@ reveal_type(None if bool() else 0) # N: Revealed type is "Union[Literal[0]?, No
 reveal_type([0, None, 0]) # N: Revealed type is "builtins.list[Union[builtins.int, None]]"
 [builtins fixtures/list.pyi]
 
-[case testOptionalWhitelistSuppressesOptionalErrors]
-# flags: --strict-optional-whitelist
-import a
-import b
-[file a.py]
-from typing import Optional
-x = None # type: Optional[str]
-x + "foo"
-
-[file b.py]
-from typing import Optional
-x = None # type: Optional[int]
-x + 1
-
-[builtins fixtures/primitives.pyi]
-
-[case testOptionalWhitelistPermitsOtherErrors]
-# flags: --strict-optional-whitelist
-import a
-import b
-[file a.py]
-from typing import Optional
-x = None # type: Optional[str]
-x + "foo"
-
-[file b.py]
-from typing import Optional
-x = None # type: Optional[int]
-x + 1
-1 + "foo"
-[builtins fixtures/primitives.pyi]
-[out]
-tmp/b.py:4: error: Unsupported operand types for + ("int" and "str")
-
-[case testOptionalWhitelistPermitsWhitelistedFiles]
-# flags: --strict-optional-whitelist **/a.py
-import a
-import b
-[file a.py]
-from typing import Optional
-x = None # type: Optional[str]
-x + "foo"
-
-[file b.py]
-from typing import Optional
-x = None # type: Optional[int]
-x + 1
-[builtins fixtures/primitives.pyi]
-[out]
-tmp/a.py:3: error: Unsupported left operand type for + ("None")
-tmp/a.py:3: note: Left operand is of type "Optional[str]"
-
 [case testNoneContextInference]
 from typing import Dict, List
 def f() -> List[None]:

test-data/unit/check-overloading.test

@@ -5986,10 +5986,10 @@ reveal_type(f2(A())) # E: No overload variant of "f2" matches argument type "A"
 if True:
  @overload # E: Single overload definition, multiple required
  def f3(x: A) -> A: ...
+ def f3(x): ...
  if maybe_true: # E: Name "maybe_true" is not defined
  @overload # E: Single overload definition, multiple required
  def g3(x: B) -> B: ...
- def f3(x): ...
 reveal_type(f3(A())) # N: Revealed type is "__main__.A"
 
 if True: