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#![allow(dead_code)]
#![warn(clippy::unused_io_amount)]
extern crate futures;
use futures::io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt};
use std::io::{self, Read};
fn question_mark<T: io::Read + io::Write>(s: &mut T) -> io::Result<()> {
s.write(b"test")?;
let mut buf = [0u8; 4];
s.read(&mut buf)?;
Ok(())
}
fn unwrap<T: io::Read + io::Write>(s: &mut T) {
s.write(b"test").unwrap();
let mut buf = [0u8; 4];
s.read(&mut buf).unwrap();
}
fn vectored<T: io::Read + io::Write>(s: &mut T) -> io::Result<()> {
s.read_vectored(&mut [io::IoSliceMut::new(&mut [])])?;
s.write_vectored(&[io::IoSlice::new(&[])])?;
Ok(())
}
fn ok(file: &str) -> Option<()> {
let mut reader = std::fs::File::open(file).ok()?;
let mut result = [0u8; 0];
reader.read(&mut result).ok()?;
Some(())
}
#[allow(clippy::redundant_closure)]
#[allow(clippy::bind_instead_of_map)]
fn or_else(file: &str) -> io::Result<()> {
let mut reader = std::fs::File::open(file)?;
let mut result = [0u8; 0];
reader.read(&mut result).or_else(|err| Err(err))?;
Ok(())
}
#[derive(Debug)]
enum Error {
Kind,
}
fn or(file: &str) -> Result<(), Error> {
let mut reader = std::fs::File::open(file).unwrap();
let mut result = [0u8; 0];
reader.read(&mut result).or(Err(Error::Kind))?;
Ok(())
}
fn combine_or(file: &str) -> Result<(), Error> {
let mut reader = std::fs::File::open(file).unwrap();
let mut result = [0u8; 0];
reader
.read(&mut result)
.or(Err(Error::Kind))
.or(Err(Error::Kind))
.expect("error");
Ok(())
}
async fn bad_async_write<W: AsyncWrite + Unpin>(w: &mut W) {
w.write(b"hello world").await.unwrap();
}
async fn bad_async_read<R: AsyncRead + Unpin>(r: &mut R) {
let mut buf = [0u8; 0];
r.read(&mut buf[..]).await.unwrap();
}
async fn io_not_ignored_async_write<W: AsyncWrite + Unpin>(mut w: W) {
// Here we're forgetting to await the future, so we should get a
// warning about _that_ (or we would, if it were enabled), but we
// won't get one about ignoring the return value.
w.write(b"hello world");
}
fn bad_async_write_closure<W: AsyncWrite + Unpin + 'static>(w: W) -> impl futures::Future<Output = io::Result<()>> {
let mut w = w;
async move {
w.write(b"hello world").await?;
Ok(())
}
}
async fn async_read_nested_or<R: AsyncRead + Unpin>(r: &mut R, do_it: bool) -> Result<[u8; 1], Error> {
let mut buf = [0u8; 1];
if do_it {
r.read(&mut buf[..]).await.or(Err(Error::Kind))?;
}
Ok(buf)
}
use tokio::io::{AsyncRead as TokioAsyncRead, AsyncReadExt as _, AsyncWrite as TokioAsyncWrite, AsyncWriteExt as _};
async fn bad_async_write_tokio<W: TokioAsyncWrite + Unpin>(w: &mut W) {
w.write(b"hello world").await.unwrap();
}
async fn bad_async_read_tokio<R: TokioAsyncRead + Unpin>(r: &mut R) {
let mut buf = [0u8; 0];
r.read(&mut buf[..]).await.unwrap();
}
async fn undetected_bad_async_write<W: AsyncWrite + Unpin>(w: &mut W) {
// It would be good to detect this case some day, but the current lint
// doesn't handle it. (The documentation says that this lint "detects
// only common patterns".)
let future = w.write(b"Hello world");
future.await.unwrap();
}
fn main() {}
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