rust/tests/ui/checked_unwrap.rs
2018-06-12 15:06:46 +02:00

102 lines
2.9 KiB
Rust

#![deny(panicking_unwrap, unnecessary_unwrap)]
#![allow(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 enoguh 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 enoguh 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
}
}
}