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#![allow(dead_code, clippy::needless_pass_by_ref_mut)]
#![allow(clippy::redundant_pattern_matching)]
#![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")?;
//~^ unused_io_amount
let mut buf = [0u8; 4];
s.read(&mut buf)?;
//~^ unused_io_amount
Ok(())
}
fn unwrap<T: io::Read + io::Write>(s: &mut T) {
s.write(b"test").unwrap();
//~^ unused_io_amount
let mut buf = [0u8; 4];
s.read(&mut buf).unwrap();
//~^ unused_io_amount
}
fn vectored<T: io::Read + io::Write>(s: &mut T) -> io::Result<()> {
s.read_vectored(&mut [io::IoSliceMut::new(&mut [])])?;
//~^ unused_io_amount
s.write_vectored(&[io::IoSlice::new(&[])])?;
//~^ unused_io_amount
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()?;
//~^ unused_io_amount
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))?;
//~^ unused_io_amount
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))?;
//~^ unused_io_amount
Ok(())
}
fn combine_or(file: &str) -> Result<(), Error> {
let mut reader = std::fs::File::open(file).unwrap();
let mut result = [0u8; 0];
reader
//~^ unused_io_amount
.read(&mut result)
.or(Err(Error::Kind))
.or(Err(Error::Kind))
.expect("error");
Ok(())
}
fn is_ok_err<T: io::Read + io::Write>(s: &mut T) {
s.write(b"ok").is_ok();
//~^ unused_io_amount
s.write(b"err").is_err();
//~^ unused_io_amount
let mut buf = [0u8; 0];
s.read(&mut buf).is_ok();
//~^ unused_io_amount
s.read(&mut buf).is_err();
//~^ unused_io_amount
}
async fn bad_async_write<W: AsyncWrite + Unpin>(w: &mut W) {
w.write(b"hello world").await.unwrap();
//~^ unused_io_amount
}
async fn bad_async_read<R: AsyncRead + Unpin>(r: &mut R) {
let mut buf = [0u8; 0];
r.read(&mut buf[..]).await.unwrap();
//~^ unused_io_amount
}
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");
//~^ unused_io_amount
}
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?;
//~^ unused_io_amount
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))?;
//~^ unused_io_amount
}
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();
//~^ unused_io_amount
}
async fn bad_async_read_tokio<R: TokioAsyncRead + Unpin>(r: &mut R) {
let mut buf = [0u8; 0];
r.read(&mut buf[..]).await.unwrap();
//~^ unused_io_amount
}
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 match_okay_underscore<T: io::Read + io::Write>(s: &mut T) {
match s.write(b"test") {
//~^ unused_io_amount
Ok(_) => todo!(),
Err(_) => todo!(),
};
let mut buf = [0u8; 4];
match s.read(&mut buf) {
//~^ unused_io_amount
Ok(_) => todo!(),
Err(_) => todo!(),
}
}
fn match_okay_underscore_read_expr<T: io::Read + io::Write>(s: &mut T) {
match s.read(&mut [0u8; 4]) {
//~^ unused_io_amount
Ok(_) => todo!(),
Err(_) => todo!(),
}
}
fn match_okay_underscore_write_expr<T: io::Read + io::Write>(s: &mut T) {
match s.write(b"test") {
//~^ unused_io_amount
Ok(_) => todo!(),
Err(_) => todo!(),
}
}
fn returned_value_should_not_lint<T: io::Read + io::Write>(s: &mut T) -> Result<usize, std::io::Error> {
s.write(b"test")
}
fn if_okay_underscore_read_expr<T: io::Read + io::Write>(s: &mut T) {
if let Ok(_) = s.read(&mut [0u8; 4]) {
//~^ unused_io_amount
todo!()
}
}
fn if_okay_underscore_write_expr<T: io::Read + io::Write>(s: &mut T) {
if let Ok(_) = s.write(b"test") {
//~^ unused_io_amount
todo!()
}
}
fn if_okay_dots_write_expr<T: io::Read + io::Write>(s: &mut T) {
if let Ok(..) = s.write(b"test") {
//~^ unused_io_amount
todo!()
}
}
fn if_okay_underscore_write_expr_true_negative<T: io::Read + io::Write>(s: &mut T) {
if let Ok(bound) = s.write(b"test") {
todo!()
}
}
fn match_okay_underscore_true_neg<T: io::Read + io::Write>(s: &mut T) {
match s.write(b"test") {
Ok(bound) => todo!(),
Err(_) => todo!(),
};
}
fn true_negative<T: io::Read + io::Write>(s: &mut T) {
let mut buf = [0u8; 4];
let read_amount = s.read(&mut buf).unwrap();
}
fn on_return_should_not_raise<T: io::Read + io::Write>(s: &mut T) -> io::Result<usize> {
/// this is bad code because it goes around the problem of handling the read amount
/// by returning it, which makes it impossible to know this is a resonpose from the
/// correct account.
let mut buf = [0u8; 4];
s.read(&mut buf)
}
pub fn unwrap_in_block(rdr: &mut dyn std::io::Read) -> std::io::Result<usize> {
let read = { rdr.read(&mut [0])? };
Ok(read)
}
pub fn consumed_example(rdr: &mut dyn std::io::Read) {
match rdr.read(&mut [0]) {
Ok(0) => println!("EOF"),
Ok(_) => println!("fully read"),
Err(_) => println!("fail"),
};
match rdr.read(&mut [0]) {
Ok(0) => println!("EOF"),
Ok(_) => println!("fully read"),
Err(_) => println!("fail"),
}
}
pub fn unreachable_or_panic(rdr: &mut dyn std::io::Read) {
{
match rdr.read(&mut [0]) {
Ok(_) => unreachable!(),
Err(_) => println!("expected"),
}
}
{
match rdr.read(&mut [0]) {
Ok(_) => panic!(),
Err(_) => println!("expected"),
}
}
}
pub fn wildcards(rdr: &mut dyn std::io::Read) {
{
match rdr.read(&mut [0]) {
Ok(1) => todo!(),
_ => todo!(),
}
}
}
fn allow_works<F: std::io::Read>(mut f: F) {
let mut data = Vec::with_capacity(100);
#[allow(clippy::unused_io_amount)]
f.read(&mut data).unwrap();
}
struct Reader {}
impl Read for Reader {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
todo!()
}
fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
// We shouldn't recommend using Read::read_exact inside Read::read_exact!
self.read(buf).unwrap();
Ok(())
}
}
fn main() {}
|
