"""Shared code between dmypy.py and dmypy_server.py.

This should be pretty lightweight and not depend on other mypy code (other than ipc).

"""

from __future__ import annotations

import json

from typing import Any, Final, Iterable

from mypy.ipc import IPCBase

DEFAULT_STATUS_FILE: Final = ".dmypy.json"

def receive(connection: IPCBase) -> Any:

"""Receive single JSON data frame from a connection.

Raise OSError if the data received is not valid JSON or if it is

not a dict.

"""

bdata = connection.read()

if not bdata:

raise OSError("No data received")

try:

data = json.loads(bdata)

except Exception as e:

raise OSError("Data received is not valid JSON") from e

if not isinstance(data, dict):

raise OSError(f"Data received is not a dict ({type(data)})")

return data

def send(connection: IPCBase, data: Any) -> None:

"""Send data to a connection encoded and framed.

The data must be JSON-serializable. We assume that a single send call is a

single frame to be sent on the connect.

"""

connection.write(json.dumps(data))

class WriteToConn:

"""Helper class to write to a connection instead of standard output."""

def __init__(self, server: IPCBase, output_key: str = "stdout") -> None:

self.server = server

self.output_key = output_key

def write(self, output: str) -> int:

resp: dict[str, Any] = {}

resp[self.output_key] = output

send(self.server, resp)

return len(output)

def writelines(self, lines: Iterable[str]) -> None:

for s in lines:

self.write(s)