ballistica/tools/efrotools/statictest.py

192 lines
8.0 KiB
Python

# Copyright (c) 2011-2019 Eric Froemling
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
# -----------------------------------------------------------------------------
"""Functionality for harnessing mypy for static type checking in unit tests."""
from __future__ import annotations
from typing import TYPE_CHECKING
import tempfile
import os
import subprocess
if TYPE_CHECKING:
from typing import Any, Type, Dict, Optional, List
# Global state:
# We maintain a single temp dir where our mypy cache and our temp
# test files live. Every time we are asked to static-check a line
# in a file we haven't seen yet, we copy it into the temp dir,
# filter it a bit to add reveal_type() statements, and run mypy on it.
# The temp dir should tear itself down when Python exits.
_tempdir: Optional[tempfile.TemporaryDirectory] = None
_statictestfiles: Dict[str, StaticTestFile] = {}
_nextfilenum: int = 1
class StaticTestFile:
"""A file which has been statically tested via mypy."""
def __init__(self, filename: str):
# pylint: disable=global-statement, invalid-name
global _tempdir, _nextfilenum
# pylint: enable=global-statement, invalid-name
from efrotools import PYTHON_BIN
self._filename = filename
# Types we *want* for lines
self.linetypes_wanted: Dict[int, str] = {}
# Types Mypy gave us for lines
self.linetypes_mypy: Dict[int, str] = {}
print(f"Running Mypy static testing on \"{filename}\"...")
with open(filename, 'r') as infile:
fdata = infile.read()
# Make sure we're running where the config is..
if not os.path.isfile('.mypy.ini'):
raise RuntimeError('.mypy.ini not found where expected.')
# Create a single shared temp dir
# (so that we can recycle our mypy cache).
if _tempdir is None:
_tempdir = tempfile.TemporaryDirectory()
# Copy our file into the temp dir with a unique name, find all
# instances of static_type_equals(), and run mypy type checks
# in those places to get static types.
tempfilepath = os.path.join(_tempdir.name, f'temp{_nextfilenum}.py')
_nextfilenum += 1
with open(tempfilepath, 'w') as outfile:
outfile.write(self.filter_file_contents(fdata))
results = subprocess.run([
PYTHON_BIN, '-m', 'mypy', '--no-error-summary', '--config-file',
'.mypy.ini', '--cache-dir', _tempdir.name, tempfilepath
],
capture_output=True,
check=False)
# HMM; it seems we get an errored return code due to reveal_type()s.
# So I guess we just have to ignore other errors, which is unforunate.
# (though if the run fails, we'll probably error when attempting to
# look up a revealed type that we don't have anyway)
lines = results.stdout.decode().splitlines()
for line in lines:
if 'Revealed type is ' in line:
finfo = line.split(' ')[0]
fparts = finfo.split(':')
assert len(fparts) == 3
linenumber = int(fparts[1])
linetype = line.split('Revealed type is ')[-1][1:-1]
self.linetypes_mypy[linenumber] = linetype
def filter_file_contents(self, contents: str) -> str:
"""Filter the provided file contents and take note of type checks."""
import ast
lines = contents.splitlines()
lines_out: List[str] = []
for lineno, line in enumerate(lines):
if 'static_type_equals(' not in line:
lines_out.append(line)
else:
# Find the location of the end parentheses.
assert ')' in line
endparen = len(line) - 1
while line[endparen] != ')':
endparen -= 1
# Find the offset to the start of the line.
offset = 0
while line[offset] == ' ':
offset += 1
# Parse this line as AST - we should find an assert
# statement containing a static_type_equals() call
# with 2 args.
tree = ast.parse(line[offset:])
assert isinstance(tree, ast.Module)
if (len(tree.body) != 1
or not isinstance(tree.body[0], ast.Assert)):
raise RuntimeError(
f"{self._filename} line {lineno+1}: expected "
f" a single assert statement.")
assertnode = tree.body[0]
callnode = assertnode.test
if (not isinstance(callnode, ast.Call)
or not isinstance(callnode.func, ast.Name)
or callnode.func.id != 'static_type_equals'
or len(callnode.args) != 2):
raise RuntimeError(
f"{self._filename} line {lineno+1}: expected "
f" a single static_type_equals() call with 2 args.")
# Use the column offsets for the 2 args along with our end
# paren offset to cut out the substrings representing the args.
arg1 = line[callnode.args[0].col_offset +
offset:callnode.args[1].col_offset + offset]
while arg1[-1] in (' ', ','):
arg1 = arg1[:-1]
arg2 = line[callnode.args[1].col_offset + offset:endparen]
# In our filtered file, replace the assert statement with
# a reveal_type() for the var, and also take note of the
# type they want it to equal.
self.linetypes_wanted[lineno + 1] = arg2
lines_out.append(' ' * offset + f'reveal_type({arg1})')
return '\n'.join(lines_out) + '\n'
def static_type_equals(value: Any, statictype: Type) -> bool:
"""Check a type statically using mypy."""
from inspect import getframeinfo, stack
# We don't actually use there here; we pull them as strings from the src.
del value
del statictype
# Get the filename and line number of the calling function.
caller = getframeinfo(stack()[1][0])
filename = caller.filename
linenumber = caller.lineno
if filename not in _statictestfiles:
_statictestfiles[filename] = StaticTestFile(filename)
wanttype = _statictestfiles[filename].linetypes_wanted[linenumber]
mypytype = _statictestfiles[filename].linetypes_mypy[linenumber]
# Do some filtering of Mypy types to simple python ones.
# (ie: 'builtins.list[builtins.int*]' -> int)
mypytype = mypytype.replace('builtins.int*', 'int')
mypytype = mypytype.replace('builtins.int', 'int')
mypytype = mypytype.replace('builtins.list', 'List')
mypytype = mypytype.replace('typing.Sequence', 'Sequence')
if wanttype != mypytype:
print(f'Mypy type "{mypytype}" does not match '
f'the desired type "{wanttype}" on line {linenumber}.')
return False
return True