"""This module makes it possible to use mypy as part of a Python application.

Since mypy still changes, the API was kept utterly simple and non-intrusive.

It just mimics command line activation without starting a new interpreter.

So the normal docs about the mypy command line apply.

Changes in the command line version of mypy will be immediately usable.

Just import this module and then call the 'run' function with a parameter of

type List[str], containing what normally would have been the command line

arguments to mypy.

Function 'run' returns a Tuple[str, str, int], namely

(<normal_report>, <error_report>, <exit_status>),

in which <normal_report> is what mypy normally writes to sys.stdout,

<error_report> is what mypy normally writes to sys.stderr and exit_status is

the exit status mypy normally returns to the operating system.

Any pretty formatting is left to the caller.

The 'run_dmypy' function is similar, but instead mimics invocation of

dmypy. Note that run_dmypy is not thread-safe and modifies sys.stdout

and sys.stderr during its invocation.

Note that these APIs don't support incremental generation of error

messages.

Trivial example of code using this module:

import sys

from mypy import api

result = api.run(sys.argv[1:])

if result[0]:

print('\nType checking report:\n')

print(result[0]) # stdout

if result[1]:

print('\nError report:\n')

print(result[1]) # stderr

print('\nExit status:', result[2])

"""

from __future__ import annotations

import sys

from io import StringIO

from typing import Callable, TextIO

def _run(main_wrapper: Callable[[TextIO, TextIO], None]) -> tuple[str, str, int]:

stdout = StringIO()

stderr = StringIO()

try:

main_wrapper(stdout, stderr)

exit_status = 0

except SystemExit as system_exit:

assert isinstance(system_exit.code, int)

exit_status = system_exit.code

return stdout.getvalue(), stderr.getvalue(), exit_status

def run(args: list[str]) -> tuple[str, str, int]:

# Lazy import to avoid needing to import all of mypy to call run_dmypy

from mypy.main import main

return _run(

lambda stdout, stderr: main(args=args, stdout=stdout, stderr=stderr, clean_exit=True)

)

def run_dmypy(args: list[str]) -> tuple[str, str, int]:

from mypy.dmypy.client import main

# A bunch of effort has been put into threading stdout and stderr

# through the main API to avoid the threadsafety problems of

# modifying sys.stdout/sys.stderr, but that hasn't been done for

# the dmypy client, so we just do the non-threadsafe thing.

def f(stdout: TextIO, stderr: TextIO) -> None:

old_stdout = sys.stdout

old_stderr = sys.stderr

try:

sys.stdout = stdout

sys.stderr = stderr

main(args)

finally:

sys.stdout = old_stdout

sys.stderr = old_stderr

return _run(f)