Turn all warnings and bare notes into errors

This means that all diagnostics are errors, which maybe have some
notes "attached" to them.
This makes sense, since all diagnostics cause an error exit code.

Fixes #6574.

Author: msullivan

mypy/build.py

@@ -2180,7 +2180,7 @@ def generate_unused_ignore_notes(self) -> None:
             # those errors to avoid spuriously flagging them as unused ignores.
             if self.meta:
                 self.verify_dependencies(suppressed_only=True)
-            self.manager.errors.generate_unused_ignore_notes(self.xpath)
+            self.manager.errors.generate_unused_ignore_errors(self.xpath)
 
 
 # Module import and diagnostic glue
@@ -2376,7 +2376,7 @@ def skipping_module(manager: BuildManager, line: int, caller_state: Optional[Sta
     manager.errors.set_file(caller_state.xpath, caller_state.id)
     manager.errors.report(line, 0,
                           "Import of '%s' ignored" % (id,),
-                          severity='note')
+                          severity='error')
     manager.errors.report(line, 0,
                           "(Using --follow-imports=error, module not passed on command line)",
                           severity='note', only_once=True)
@@ -2392,7 +2392,7 @@ def skipping_ancestor(manager: BuildManager, id: str, path: str, ancestor_for: '
     manager.errors.set_import_context([])
     manager.errors.set_file(ancestor_for.xpath, ancestor_for.id)
     manager.errors.report(-1, -1, "Ancestor package '%s' ignored" % (id,),
-                          severity='note', only_once=True)
+                          severity='error', only_once=True)
     manager.errors.report(-1, -1,
                           "(Using --follow-imports=error, submodule passed on command line)",
                           severity='note', only_once=True)

mypy/checker.py

@@ -951,7 +951,7 @@ def check_func_def(self, defn: FuncItem, typ: CallableType, name: Optional[str])
                     # entirely pass/Ellipsis.
                     if isinstance(return_type, UninhabitedType):
                         # This is a NoReturn function
-                        self.msg.note(message_registry.INVALID_IMPLICIT_RETURN, defn)
+                        self.msg.fail(message_registry.INVALID_IMPLICIT_RETURN, defn)
                     else:
                         self.msg.fail(message_registry.MISSING_RETURN_STATEMENT, defn)
 
@@ -2793,7 +2793,7 @@ def visit_assert_stmt(self, s: AssertStmt) -> None:
             self.expr_checker.accept(s.msg)
 
         if isinstance(s.expr, TupleExpr) and len(s.expr.items) > 0:
-            self.warn(message_registry.MALFORMED_ASSERT, s)
+            self.fail(message_registry.MALFORMED_ASSERT, s)
 
         # If this is asserting some isinstance check, bind that type in the following code
         true_map, _ = self.find_isinstance_check(s.expr)
@@ -3747,10 +3747,6 @@ def fail(self, msg: str, context: Context) -> None:
         """Produce an error message."""
         self.msg.fail(msg, context)
 
-    def warn(self, msg: str, context: Context) -> None:
-        """Produce a warning message."""
-        self.msg.warn(msg, context)
-
     def note(self, msg: str, context: Context, offset: int = 0) -> None:
         """Produce a note."""
         self.msg.note(msg, context, offset=offset)

mypy/checkmember.py

@@ -328,7 +328,6 @@ def analyze_member_var_access(name: str,
         # independently of types.
         if mx.is_lvalue and not mx.chk.get_final_context():
             check_final_member(name, info, mx.msg, mx.context)
-
         return analyze_var(name, v, itype, info, mx, implicit=implicit)
     elif isinstance(v, FuncDef):
         assert False, "Did not expect a function"

mypy/errors.py

@@ -299,13 +299,13 @@ def clear_errors_in_targets(self, path: str, targets: Set[str]) -> None:
                     self.only_once_messages.remove(info.message)
             self.error_info_map[path] = new_errors
 
-    def generate_unused_ignore_notes(self, file: str) -> None:
+    def generate_unused_ignore_errors(self, file: str) -> None:
         ignored_lines = self.ignored_lines[file]
         if not self.is_typeshed_file(file) and file not in self.ignored_files:
             for line in ignored_lines - self.used_ignored_lines[file]:
                 # Don't use report since add_error_info will ignore the error!
                 info = ErrorInfo(self.import_context(), file, self.current_module(), None,
-                                 None, line, -1, 'note', "unused 'type: ignore' comment",
+                                 None, line, -1, 'error', "unused 'type: ignore' comment",
                                  False, False)
                 self._add_error_info(file, info)
 

mypy/messages.py

@@ -135,11 +135,6 @@ def note_multiline(self, messages: str, context: Context, file: Optional[str] =
             self.report(msg, context, 'note', file=file, origin=origin,
                         offset=offset)
 
-    def warn(self, msg: str, context: Context, file: Optional[str] = None,
-             origin: Optional[Context] = None) -> None:
-        """Report a warning message (unless disabled)."""
-        self.report(msg, context, 'warning', file=file, origin=origin)
-
     def quote_type_string(self, type_string: str) -> str:
         """Quotes a type representation for use in messages."""
         no_quote_regex = r'^<(tuple|union): \d+ items>$'
@@ -1065,7 +1060,7 @@ def unsupported_type_type(self, item: Type, context: Context) -> None:
         self.fail('Unsupported type Type[{}]'.format(self.format(item)), context)
 
     def redundant_cast(self, typ: Type, context: Context) -> None:
-        self.note('Redundant cast to {}'.format(self.format(typ)), context)
+        self.fail('Redundant cast to {}'.format(self.format(typ)), context)
 
     def unimported_type_becomes_any(self, prefix: str, typ: Type, ctx: Context) -> None:
         self.fail("{} becomes {} due to an unfollowed import".format(prefix, self.format(typ)),
@@ -1156,7 +1151,7 @@ def disallowed_any_type(self, typ: Type, context: Context) -> None:
     def incorrectly_returning_any(self, typ: Type, context: Context) -> None:
         message = 'Returning Any from function declared to return {}'.format(
             self.format(typ))
-        self.warn(message, context)
+        self.fail(message, context)
 
     def untyped_decorated_function(self, typ: Type, context: Context) -> None:
         if isinstance(typ, AnyType):

test-data/unit/check-fastparse.test

@@ -319,10 +319,10 @@ def g():  # E: Type signature has too many arguments
 [case testFastParseMalformedAssert]
 
 assert 1, 2
-assert (1, 2)  # W: Assertion is always true, perhaps remove parentheses?
-assert (1, 2), 3  # W: Assertion is always true, perhaps remove parentheses?
+assert (1, 2)  # E: Assertion is always true, perhaps remove parentheses?
+assert (1, 2), 3  # E: Assertion is always true, perhaps remove parentheses?
 assert ()
-assert (1,)  # W: Assertion is always true, perhaps remove parentheses?
+assert (1,)  # E: Assertion is always true, perhaps remove parentheses?
 
 [case testFastParseAssertMessage]
 

test-data/unit/check-flags.test

@@ -286,7 +286,7 @@ def f() -> NoReturn:
 # flags: --warn-no-return
 from mypy_extensions import NoReturn
 
-def f() -> NoReturn:  # N: Implicit return in function which does not return
+def f() -> NoReturn:  # E: Implicit return in function which does not return
   non_trivial_function = 1
 [builtins fixtures/dict.pyi]
 
@@ -432,7 +432,7 @@ x + ""
 [file mod.py]
 deliberate syntax error
 [out]
-main:2: note: Import of 'mod' ignored
+main:2: error: Import of 'mod' ignored
 main:2: note: (Using --follow-imports=error, module not passed on command line)
 
 [case testIgnoreMissingImportsFalse]

test-data/unit/check-incremental.test

@@ -1783,10 +1783,10 @@ import a
 [file a.py.2]
 //
 [out1]
-main:2: note: Import of 'a' ignored
+main:2: error: Import of 'a' ignored
 main:2: note: (Using --follow-imports=error, module not passed on command line)
 [out2]
-main:2: note: Import of 'a' ignored
+main:2: error: Import of 'a' ignored
 main:2: note: (Using --follow-imports=error, module not passed on command line)
 
 [case testIncrementalFollowImportsVariable]

test-data/unit/check-modules.test

@@ -992,7 +992,7 @@ import mod
 [file mod.py]
 [builtins fixtures/module.pyi]
 [out]
-tmp/main.py:1: note: Import of 'mod' ignored
+tmp/main.py:1: error: Import of 'mod' ignored
 tmp/main.py:1: note: (Using --follow-imports=error, module not passed on command line)
 
 [case testAncestorSuppressedWhileAlmostSilent]
@@ -1002,7 +1002,7 @@ tmp/main.py:1: note: (Using --follow-imports=error, module not passed on command
 [file foo/__init__.py]
 [builtins fixtures/module.pyi]
 [out]
-tmp/foo/bar.py: note: Ancestor package 'foo' ignored
+tmp/foo/bar.py: error: Ancestor package 'foo' ignored
 tmp/foo/bar.py: note: (Using --follow-imports=error, submodule passed on command line)
 
 [case testStubImportNonStubWhileSilent]

test-data/unit/check-warnings.test

@@ -10,7 +10,7 @@ a = 1
 b = cast(str, a)
 c = cast(int, a)
 [out]
-main:5: note: Redundant cast to "int"
+main:5: error: Redundant cast to "int"
 
 [case testRedundantCastWithIsinstance]
 # flags: --warn-redundant-casts
@@ -20,7 +20,7 @@ if isinstance(x, str):
     cast(str, x)
 [builtins fixtures/isinstance.pyi]
 [out]
-main:5: note: Redundant cast to "str"
+main:5: error: Redundant cast to "str"
 
 [case testCastToSuperclassNotRedundant]
 # flags: --warn-redundant-casts
@@ -45,7 +45,7 @@ a = 1
 if int():
     a = 'a' # type: ignore
 if int():
-    a = 2 # type: ignore # N: unused 'type: ignore' comment
+    a = 2 # type: ignore # E: unused 'type: ignore' comment
 if int():
     a = 'b' # E: Incompatible types in assignment (expression has type "str", variable has type "int")
 
@@ -57,8 +57,8 @@ from m import * # type: ignore
 [file m.py]
 pass
 [out]
-main:3: note: unused 'type: ignore' comment
-main:4: note: unused 'type: ignore' comment
+main:3: error: unused 'type: ignore' comment
+main:4: error: unused 'type: ignore' comment
 
 
 -- No return
@@ -144,7 +144,7 @@ from typing import Any
 def g() -> Any: pass
 def f() -> int: return g()
 [out]
-main:4: warning: Returning Any from function declared to return "int"
+main:4: error: Returning Any from function declared to return "int"
 
 [case testReturnAnyForNotImplementedInBinaryMagicMethods]
 # flags: --warn-return-any
@@ -159,7 +159,7 @@ class A:
     def some(self) -> bool: return NotImplemented
 [builtins fixtures/notimplemented.pyi]
 [out]
-main:3: warning: Returning Any from function declared to return "bool"
+main:3: error: Returning Any from function declared to return "bool"
 
 [case testReturnAnyFromTypedFunctionWithSpecificFormatting]
 # flags: --warn-return-any
@@ -174,7 +174,7 @@ typ = Tuple[int, int, int, int, int, int, int, int, int, int, int, int, int,
 def g() -> Any: pass
 def f() -> typ: return g()
 [out]
-main:11: warning: Returning Any from function declared to return <tuple: 91 items>
+main:11: error: Returning Any from function declared to return <tuple: 91 items>
 
 [case testReturnAnySilencedFromTypedFunction]
 # flags: --warn-return-any