Add from __future__ import annotations everywhere. (#13391)

This will be nice for if anyone wants to use slicker new syntax for mypy internals without 
worrying about if the file already has it or not.

mypy/dmypy/__main__.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from mypy.dmypy.client import console_entry
 
 if __name__ == "__main__":

mypy/dmypy/client.py

@@ -4,6 +4,8 @@
 rather than having to read it back from disk on each run.
 """
 
+from __future__ import annotations
+
 import argparse
 import base64
 import json

mypy/plugins/attrs.py

@@ -1,5 +1,7 @@
 """Plugin for supporting the attrs library (http://www.attrs.org)"""
 
+from __future__ import annotations
+
 from typing import Dict, Iterable, List, Optional, Tuple, cast
 from typing_extensions import Final
 

mypy/plugins/common.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from typing import List, Optional, Union
 
 from mypy.fixup import TypeFixer

mypy/plugins/ctypes.py

@@ -1,5 +1,7 @@
 """Plugin to provide accurate types for some parts of the ctypes module."""
 
+from __future__ import annotations
+
 from typing import List, Optional
 
 # Fully qualified instead of "from mypy.plugin import ..." to avoid circular import problems.

mypy/plugins/dataclasses.py

@@ -1,5 +1,7 @@
 """Plugin that provides support for dataclasses."""
 
+from __future__ import annotations
+
 from typing import Dict, List, Optional, Set, Tuple
 from typing_extensions import Final
 

mypy/plugins/default.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from functools import partial
 from typing import Callable, List, Optional
 

mypy/plugins/enums.py

@@ -10,6 +10,8 @@
 we actually bake some of it directly in to the semantic analysis layer (see
 semanal_enum.py).
 """
+from __future__ import annotations
+
 from typing import Iterable, Optional, Sequence, TypeVar, cast
 from typing_extensions import Final
 

mypy/plugins/functools.py

@@ -1,4 +1,6 @@
 """Plugin for supporting the functools standard library module."""
+from __future__ import annotations
+
 from typing import Dict, NamedTuple, Optional
 from typing_extensions import Final
 

mypy/plugins/singledispatch.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from typing import List, NamedTuple, Optional, Sequence, TypeVar, Union
 from typing_extensions import Final
 

mypy/server/astdiff.py

@@ -50,6 +50,8 @@ class level -- these are handled at attribute level (say, 'mod.Cls.method'
   fine-grained dependencies.
 """
 
+from __future__ import annotations
+
 from typing import Dict, Optional, Sequence, Set, Tuple, Union
 
 from mypy.nodes import (

mypy/server/astmerge.py

@@ -45,6 +45,8 @@
 See the main entry point merge_asts for more details.
 """
 
+from __future__ import annotations
+
 from typing import Dict, List, Optional, Tuple, TypeVar, cast
 
 from mypy.nodes import (

mypy/server/aststrip.py

@@ -31,6 +31,8 @@
   even though some identities are preserved.
 """
 
+from __future__ import annotations
+
 from contextlib import contextmanager, nullcontext
 from typing import Dict, Iterator, Optional, Tuple, Union
 

mypy/server/deps.py

@@ -79,6 +79,8 @@ class 'mod.Cls'. This can also refer to an attribute inherited from a
 Test cases for this module live in 'test-data/unit/deps*.test'.
 """
 
+from __future__ import annotations
+
 from typing import DefaultDict, Dict, List, Optional, Set, Tuple
 
 from mypy.nodes import (

mypy/server/mergecheck.py

@@ -1,5 +1,7 @@
 """Check for duplicate AST nodes after merge."""
 
+from __future__ import annotations
+
 from typing import Dict, List, Tuple
 from typing_extensions import Final
 

mypy/server/objgraph.py

@@ -1,5 +1,7 @@
 """Find all objects reachable from a root object."""
 
+from __future__ import annotations
+
 import types
 import weakref
 from collections.abc import Iterable

mypy/server/subexpr.py

@@ -1,5 +1,7 @@
 """Find all subexpressions of an AST node."""
 
+from __future__ import annotations
+
 from typing import List
 
 from mypy.nodes import (

mypy/server/trigger.py

@@ -1,5 +1,7 @@
 """AST triggers that are used for fine-grained dependency handling."""
 
+from __future__ import annotations
+
 from typing_extensions import Final
 
 # Used as a suffix for triggers to handle "from m import *" dependencies (see also

mypy/server/update.py

@@ -112,6 +112,8 @@
 test cases (test-data/unit/fine-grained*.test).
 """
 
+from __future__ import annotations
+
 import os
 import sys
 import time

mypy/test/config.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import os.path
 
 provided_prefix = os.getenv("MYPY_TEST_PREFIX", None)

mypy/test/data.py

@@ -1,5 +1,7 @@
 """Utilities for processing .test files containing test case descriptions."""
 
+from __future__ import annotations
+
 import os
 import os.path
 import posixpath

mypy/test/helpers.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import contextlib
 import os
 import pathlib

mypy/test/test_find_sources.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import os
 import shutil
 import tempfile

mypy/test/testapi.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import sys
 from io import StringIO
 

mypy/test/testargs.py

@@ -4,6 +4,8 @@
 defaults, and that argparse doesn't assign any new members to the Options
 object it creates.
 """
+from __future__ import annotations
+
 import argparse
 import sys
 

mypy/test/testcheck.py

@@ -1,5 +1,7 @@
 """Type checker test cases"""
 
+from __future__ import annotations
+
 import os
 import re
 import sys

mypy/test/testcmdline.py

@@ -4,6 +4,8 @@
 whole tree.
 """
 
+from __future__ import annotations
+
 import os
 import re
 import subprocess

mypy/test/testconstraints.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from mypy.constraints import SUBTYPE_OF, SUPERTYPE_OF, Constraint, infer_constraints
 from mypy.test.helpers import Suite
 from mypy.test.typefixture import TypeFixture

mypy/test/testdaemon.py

@@ -5,6 +5,8 @@
 This also includes some unit tests.
 """
 
+from __future__ import annotations
+
 import os
 import subprocess
 import sys

mypy/test/testdeps.py

@@ -1,5 +1,7 @@
 """Test cases for generating node-level dependencies (for fine-grained incremental checking)"""
 
+from __future__ import annotations
+
 import os
 from collections import defaultdict
 from typing import DefaultDict, Dict, List, Optional, Set, Tuple

mypy/test/testdiff.py

@@ -1,5 +1,7 @@
 """Test cases for AST diff (used for fine-grained incremental checking)"""
 
+from __future__ import annotations
+
 import os
 from typing import Dict, List, Optional, Tuple
 

mypy/test/testerrorstream.py

@@ -1,4 +1,6 @@
 """Tests for mypy incremental error output."""
+from __future__ import annotations
+
 from typing import List
 
 from mypy import build

mypy/test/testfinegrained.py

@@ -12,6 +12,8 @@
 on specified sources.
 """
 
+from __future__ import annotations
+
 import os
 import re
 import sys

mypy/test/testfinegrainedcache.py

@@ -5,6 +5,8 @@
 
 # We can't "import FineGrainedSuite from ..." because that will cause pytest
 # to collect the non-caching tests when running this file.
+from __future__ import annotations
+
 import mypy.test.testfinegrained
 
 

mypy/test/testformatter.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from unittest import TestCase, main
 
 from mypy.util import split_words, trim_source_line

mypy/test/testfscache.py

@@ -1,5 +1,7 @@
 """Unit tests for file system cache."""
 
+from __future__ import annotations
+
 import os
 import shutil
 import sys

mypy/test/testgraph.py

@@ -1,5 +1,7 @@
 """Test cases for graph processing code in build.py."""
 
+from __future__ import annotations
+
 import sys
 from typing import AbstractSet, Dict, List, Set
 

mypy/test/testinfer.py

@@ -1,5 +1,7 @@
 """Test cases for type inference helper functions."""
 
+from __future__ import annotations
+
 from typing import Dict, List, Optional, Set, Tuple, Union
 
 from mypy.argmap import map_actuals_to_formals

mypy/test/testipc.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import sys
 import time
 from multiprocessing import Process, Queue

mypy/test/testmerge.py

@@ -1,5 +1,7 @@
 """Test cases for AST merge (used for fine-grained incremental checking)"""
 
+from __future__ import annotations
+
 import os
 import shutil
 from typing import Dict, List, Optional, Tuple

mypy/test/testmodulefinder.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import os
 
 from mypy.modulefinder import FindModuleCache, ModuleNotFoundReason, SearchPaths

mypy/test/testmypyc.py

@@ -1,5 +1,7 @@
 """A basic check to make sure that we are using a mypyc-compiled version when expected."""
 
+from __future__ import annotations
+
 import os
 from unittest import TestCase
 

mypy/test/testparse.py

@@ -1,5 +1,7 @@
 """Tests for the mypy parser."""
 
+from __future__ import annotations
+
 import sys
 
 from pytest import skip

mypy/test/testpep561.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import os
 import re
 import subprocess

mypy/test/testpythoneval.py

@@ -10,6 +10,8 @@
       this suite would slow down the main suite too much.
 """
 
+from __future__ import annotations
+
 import os
 import os.path
 import re

mypy/test/testreports.py

@@ -1,4 +1,6 @@
 """Test cases for reports generated by mypy."""
+from __future__ import annotations
+
 import textwrap
 
 from mypy.report import CoberturaPackage, get_line_rate

mypy/test/testsemanal.py

@@ -1,5 +1,7 @@
 """Semantic analyzer test cases"""
 
+from __future__ import annotations
+
 import os.path
 import sys
 from typing import Dict, List

mypy/test/testsolve.py

@@ -1,5 +1,7 @@
 """Test cases for the constraint solver used in type inference."""
 
+from __future__ import annotations
+
 from typing import List, Optional, Tuple, Union
 
 from mypy.constraints import SUBTYPE_OF, SUPERTYPE_OF, Constraint

mypy/test/teststubgen.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import io
 import os.path
 import re

mypy/test/teststubinfo.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import unittest
 
 from mypy.stubinfo import is_legacy_bundled_package

mypy/test/teststubtest.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import contextlib
 import inspect
 import io

mypy/test/testsubtypes.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from mypy.nodes import CONTRAVARIANT, COVARIANT, INVARIANT
 from mypy.subtypes import is_subtype
 from mypy.test.helpers import Suite, skip

mypy/test/testtransform.py

@@ -1,5 +1,7 @@
 """Identity AST transform test cases"""
 
+from __future__ import annotations
+
 import os.path
 
 from mypy import build