uvloop 0.22.1: EventLoopPolicy, install, new_event_loop

# uvloop: Fast asyncio Event Loop (pkg:pypi/uvloop@0.22.1)

## Prior Network Solutions

The network query for `verify pkg:pypi/uvloop@0.22.1` returned NO_SAFE_MATCH.

## Release Pinned

- `uvloop`: 0.22.1

## Observed Behaviour

In `uvloop` 0.22.1:
1. `uvloop.EventLoopPolicy()` instantiates an `asyncio.AbstractEventLoopPolicy` that creates `uvloop.Loop` instances upon calling `new_event_loop()`.
2. `uvloop.install()` installs `uvloop.EventLoopPolicy` as the default event loop policy via `asyncio.set_event_loop_policy()`.
3. `uvloop.new_event_loop()` returns a fresh, unclosed `uvloop.Loop` instance that can execute async coroutines via `run_until_complete()`.
4. `uvloop.run(coro)` creates a new uvloop event loop, runs the coroutine to completion, and returns its result.
5. `uvloop.run(coro)` propagates exceptions raised within the coroutine.
6. `uvloop.run(obj)` raises `TypeError` if passed a non-coroutine object.

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify pkg:pypi/uvloop@0.22.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:pypi/uvloop@0.22.1
Demonstrate these symbols/APIs:
  - uvloop.EventLoopPolicy
  - uvloop.install
  - uvloop.new_event_loop
  - uvloop.run

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:bbe1bad0eb43decaee81946c826973f51356cecd553ac7897cf147915e566dd2","contract":["uvloop.EventLoopPolicy implements asyncio.AbstractEventLoopPolicy and creates uvloop.Loop instances","uvloop.install sets uvloop.EventLoopPolicy as the default asyncio event loop policy","uvloop.new_event_loop returns a new unclosed uvloop.Loop instance","uvloop.run executes an async coroutine to completion and returns its result","uvloop.run propagates unhandled exceptions raised inside the coroutine","uvloop.run raises TypeError when passed a non-coroutine object"],"goal":"verify pkg:pypi/uvloop@0.22.1","kind":"HOW","packages":["pkg:pypi/uvloop@0.22.1"],"schemaVersion":1,"symbols":["uvloop.EventLoopPolicy","uvloop.install","uvloop.new_event_loop","uvloop.run"]},"contractCommand":["python","test/contract.py"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"pypi","executionContext":"python","language":"python","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"pip","runtime":"python","runtimeVersion":"3.12","schemaVersion":1},"license":"MIT-0","packages":["pkg:pypi/uvloop@0.22.1"],"schemaVersion":1,"subject":"pkg:pypi/uvloop@0.22.1","symbols":["uvloop.EventLoopPolicy","uvloop.install","uvloop.new_event_loop","uvloop.run"],"verifierAdapter":"python@1"}

uvloop==0.22.1

{
  "schemaVersion": 1,
  "goal": "verify pkg:pypi/uvloop@0.22.1",
  "kind": "HOW",
  "packages": [
    "pkg:pypi/uvloop@0.22.1"
  ],
  "symbols": [
    "uvloop.EventLoopPolicy",
    "uvloop.install",
    "uvloop.new_event_loop",
    "uvloop.run"
  ]
}

import asyncio
import sys
import uvloop


def test_event_loop_policy() -> None:
    policy = uvloop.EventLoopPolicy()
    assert isinstance(policy, asyncio.AbstractEventLoopPolicy)

    loop = policy.new_event_loop()
    try:
        assert isinstance(loop, uvloop.Loop)
        assert isinstance(loop, asyncio.AbstractEventLoop)
    finally:
        loop.close()


def test_install_policy() -> None:
    uvloop.install()
    current_policy = asyncio.get_event_loop_policy()
    assert isinstance(current_policy, uvloop.EventLoopPolicy)


def test_new_event_loop() -> None:
    loop = uvloop.new_event_loop()
    try:
        assert isinstance(loop, uvloop.Loop)
        assert not loop.is_running()
        assert not loop.is_closed()

        async def compute() -> int:
            return 42

        res = loop.run_until_complete(compute())
        assert res == 42
    finally:
        loop.close()
    assert loop.is_closed()


def test_run_success() -> None:
    async def fetch_payload():
        await asyncio.sleep(0.01)
        return {"status": "ok", "items": [1, 2, 3]}

    result = uvloop.run(fetch_payload())
    assert result == {"status": "ok", "items": [1, 2, 3]}


def test_run_exception() -> None:
    async def faulty_task():
        await asyncio.sleep(0.01)
        raise ValueError("simulated execution error")

    try:
        uvloop.run(faulty_task())
        raise AssertionError("Expected ValueError from uvloop.run")
    except ValueError as exc:
        assert str(exc) == "simulated execution error"


def test_run_type_error() -> None:
    try:
        uvloop.run("not a coroutine")  # type: ignore
        raise AssertionError("Expected TypeError when passing non-coroutine to uvloop.run")
    except TypeError:
        pass


def main() -> None:
    test_event_loop_policy()
    test_install_policy()
    test_new_event_loop()
    test_run_success()
    test_run_exception()
    test_run_type_error()
    print("All uvloop contract assertions passed successfully.")


if __name__ == "__main__":
    main()