Change to error code only for exhaustive match

Author: Don-Burns

docs/source/command_line.rst

@@ -799,48 +799,6 @@ of the above sections.
         x = 'a string'
         x.trim()  # error: "str" has no attribute "trim"  [attr-defined]
 
-.. option:: --disallow-inexhaustive-match-statements
-
-   This flag will cause mypy to report an error whenever it encounters a match statement
-   that does not cover all possible cases.
-
-    .. code-block:: python
-
-        import enum
-
-
-        class Color(enum.Enum):
-            RED = 1
-            BLUE = 2
-
-        val: Color = Color.RED
-
-        # without --disallow-inexhaustive-match-statements
-        match val:
-            case Color.RED:
-                print("red")
-
-        # Also no issues without --disallow-inexhaustive-match-statements, but this is exhaustive
-        match val:
-            case Color.RED:
-                print("red")
-            case _:
-                print("other")
-
-        # with --disallow-inexhaustive-match-statements
-        # error: Cases within match statement do not exhaustively handle all values: "Literal[Color.BLUE]". If not intended to handle all cases, use `case _: pass`
-        match val:
-            case Color.RED:
-                print("red")
-
-        # no error with --disallow-inexhaustive-match-statements since all cases are handled
-        match val:
-            case Color.RED:
-                print("red")
-            case _:
-                print("other")
-
-
 
 .. _configuring-error-messages:
 

docs/source/error_code_list2.rst

@@ -619,7 +619,7 @@ Example:
 Check that match statements match exhaustively [match-exhaustive]
 -----------------------------------------------------------------------
 
-If you use :option:`--disallow-inexhaustive-match-statements <mypy --disallow-inexhaustive-match-statements>`,
+If enabled with :option:`--enable-error-code exhaustive-match <mypy --enable-error-code>`,
 mypy generates an error if a match statement does not match all possible cases/types.
 
 
@@ -636,25 +636,25 @@ Example:
 
         val: Color = Color.RED
 
-        # without --disallow-inexhaustive-match-statements
+        # without --enable-error-code exhaustive-match
         match val:
             case Color.RED:
                 print("red")
 
-        # Also no issues without --disallow-inexhaustive-match-statements, but this is exhaustive
+        # Also no issues without --enable-error-code exhaustive-match, but this is exhaustive
         match val:
             case Color.RED:
                 print("red")
             case _:
                 print("other")
 
-        # with --disallow-inexhaustive-match-statements
+        # with --enable-error-code exhaustive-match
         # error: Cases within match statement do not exhaustively handle all values: "Literal[Color.BLUE]". If not intended to handle all cases, use `case _: pass`
         match val:
             case Color.RED:
                 print("red")
 
-        # no error with --disallow-inexhaustive-match-statements since all cases are handled
+        # no error with --enable-error-code exhaustive-match since all cases are handled
         match val:
             case Color.RED:
                 print("red")

docs/source/literal_types.rst

@@ -471,7 +471,7 @@ Exhaustiveness checking is also supported for match statements (Python 3.10 and
 
 For match statements specifically, inexhaustive matches can be caught
 without needing to use ``assert_never`` by using
-:option:`--disallow-inexhaustive-match-statements <mypy --disallow-inexhaustive-match-statements>`.
+:option:`--enable-error-code exhaustive-match <mypy --enable-error-code>`.
 
 
 Extra Enum checks

mypy/checker.py

@@ -5511,10 +5511,7 @@ def visit_match_stmt(self, s: MatchStmt) -> None:
                 self.push_type_map(else_map, from_assignment=False)
                 unmatched_types = else_map
 
-            if (
-                self.options.disallow_inexhaustive_match_statements is True
-                and unmatched_types is not None
-            ):
+            if unmatched_types is not None:
                 for typ in set(unmatched_types.values()):
                     self.msg.match_statement_inexhaustive_match(typ, s)
 

mypy/errorcodes.py

@@ -265,7 +265,10 @@ def __hash__(self) -> int:
     default_enabled=False,
 )
 EXHAUSTIVE_MATCH: Final = ErrorCode(
-    "exhaustive-match", "Reject match statements that are not exhaustive", "General"
+    "exhaustive-match",
+    "Reject match statements that are not exhaustive",
+    "General",
+    default_enabled=False,
 )
 
 # Syntax errors are often blocking.

mypy/main.py

@@ -931,13 +931,6 @@ def add_invertible_flag(
         "and makes arguments prepended via Concatenate positional-only",
         group=strictness_group,
     )
-    add_invertible_flag(
-        "--disallow-inexhaustive-match-statements",
-        default=False,
-        strict_flag=False,
-        help="Raise type error for match statements that do not match exhaustively",
-        group=strictness_group,
-    )
 
     strict_help = "Strict mode; enables the following flags: {}".format(
         ", ".join(strict_flag_names)

mypy/options.py

@@ -349,9 +349,6 @@ def __init__(self) -> None:
         # Use this sparingly to avoid tests diverging from non-test behavior.
         self.test_env = False
 
-        # Only allow exhaustive match statements
-        self.disallow_inexhaustive_match_statements = False
-
         # -- experimental options --
         self.shadow_file: list[list[str]] | None = None
         self.show_column_numbers: bool = False

test-data/unit/check-python310.test

@@ -2669,7 +2669,7 @@ match b:
 
 
 [case testExhaustiveMatchWithFlag]
-# flags: --disallow-inexhaustive-match-statements
+# flags: --enable-error-code exhaustive-match
 
 a: int = 5
 match a:
@@ -2686,7 +2686,7 @@ match b:
         pass
 
 [case testNonExhaustiveMatchWithFlag]
-# flags: --disallow-inexhaustive-match-statements
+# flags: --enable-error-code exhaustive-match
 
 a: int = 5
 match a: # E: Cases within match statement do not exhaustively handle all values: "int". If not intended to handle all cases, use `case _: pass`
@@ -2699,7 +2699,7 @@ match b: # E: Cases within match statement do not exhaustively handle all values
         pass
 
 [case testNonExhaustiveMatchEnumWithFlag]
-# flags: --disallow-inexhaustive-match-statements
+# flags: --enable-error-code exhaustive-match
 
 import enum
 
@@ -2720,7 +2720,7 @@ match val: # E: Cases within match statement do not exhaustively handle all valu
 
 
 [case testExhaustiveMatchEnumWithFlag]
-# flags: --disallow-inexhaustive-match-statements
+# flags: --enable-error-code exhaustive-match
 
 import enum
 
@@ -2739,7 +2739,7 @@ match val:
 [builtins fixtures/enum.pyi]
 
 [case testNonExhaustiveMatchEnumMultipleMissingMatchesWithFlag]
-# flags: --disallow-inexhaustive-match-statements
+# flags: --enable-error-code exhaustive-match
 
 import enum
 
@@ -2758,7 +2758,7 @@ match val: # E: Cases within match statement do not exhaustively handle all valu
 [builtins fixtures/enum.pyi]
 
 [case testExhaustiveMatchEnumFallbackWithFlag]
-# flags: --disallow-inexhaustive-match-statements
+# flags: --enable-error-code exhaustive-match
 
 import enum