rust-clippy/tests/ui/checked_unwrap.rs
2018-10-11 12:16:22 +02:00

113 lines
3.3 KiB
Rust

// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![deny(clippy::panicking_unwrap, clippy::unnecessary_unwrap)]
#![allow(clippy::if_same_then_else)]
fn main() {
let x = Some(());
if x.is_some() {
x.unwrap(); // unnecessary
} else {
x.unwrap(); // will panic
}
if x.is_none() {
x.unwrap(); // will panic
} else {
x.unwrap(); // unnecessary
}
let mut x: Result<(), ()> = Ok(());
if x.is_ok() {
x.unwrap(); // unnecessary
x.unwrap_err(); // will panic
} else {
x.unwrap(); // will panic
x.unwrap_err(); // unnecessary
}
if x.is_err() {
x.unwrap(); // will panic
x.unwrap_err(); // unnecessary
} else {
x.unwrap(); // unnecessary
x.unwrap_err(); // will panic
}
if x.is_ok() {
x = Err(());
x.unwrap(); // not unnecessary because of mutation of x
// it will always panic but the lint is not smart enough to see this (it only checks if conditions).
} else {
x = Ok(());
x.unwrap_err(); // not unnecessary because of mutation of x
// it will always panic but the lint is not smart enough to see this (it only checks if conditions).
}
}
fn test_complex_conditions() {
let x: Result<(), ()> = Ok(());
let y: Result<(), ()> = Ok(());
if x.is_ok() && y.is_err() {
x.unwrap(); // unnecessary
x.unwrap_err(); // will panic
y.unwrap(); // will panic
y.unwrap_err(); // unnecessary
} else {
// not statically determinable whether any of the following will always succeed or always fail:
x.unwrap();
x.unwrap_err();
y.unwrap();
y.unwrap_err();
}
if x.is_ok() || y.is_ok() {
// not statically determinable whether any of the following will always succeed or always fail:
x.unwrap();
y.unwrap();
} else {
x.unwrap(); // will panic
x.unwrap_err(); // unnecessary
y.unwrap(); // will panic
y.unwrap_err(); // unnecessary
}
let z: Result<(), ()> = Ok(());
if x.is_ok() && !(y.is_ok() || z.is_err()) {
x.unwrap(); // unnecessary
x.unwrap_err(); // will panic
y.unwrap(); // will panic
y.unwrap_err(); // unnecessary
z.unwrap(); // unnecessary
z.unwrap_err(); // will panic
}
if x.is_ok() || !(y.is_ok() && z.is_err()) {
// not statically determinable whether any of the following will always succeed or always fail:
x.unwrap();
y.unwrap();
z.unwrap();
} else {
x.unwrap(); // will panic
x.unwrap_err(); // unnecessary
y.unwrap(); // unnecessary
y.unwrap_err(); // will panic
z.unwrap(); // will panic
z.unwrap_err(); // unnecessary
}
}
fn test_nested() {
fn nested() {
let x = Some(());
if x.is_some() {
x.unwrap(); // unnecessary
} else {
x.unwrap(); // will panic
}
}
}