rust/tests/ui/len_zero.rs
2017-02-07 21:05:30 +01:00

164 lines
3.6 KiB
Rust

#![feature(plugin)]
#![plugin(clippy)]
#![deny(len_without_is_empty, len_zero)]
#![allow(dead_code, unused)]
pub struct PubOne;
impl PubOne {
pub fn len(self: &Self) -> isize { //~ERROR item `PubOne` has a public `len` method but no corresponding `is_empty`
1
}
}
struct NotPubOne;
impl NotPubOne {
pub fn len(self: &Self) -> isize { // no error, len is pub but `NotPubOne` is not exported anyway
1
}
}
struct One;
impl One {
fn len(self: &Self) -> isize { // no error, len is private, see #1085
1
}
}
pub trait PubTraitsToo {
fn len(self: &Self) -> isize; //~ERROR trait `PubTraitsToo` has a `len` method but no `is_empty`
}
impl PubTraitsToo for One {
fn len(self: &Self) -> isize {
0
}
}
trait TraitsToo {
fn len(self: &Self) -> isize; // no error, len is private, see #1085
}
impl TraitsToo for One {
fn len(self: &Self) -> isize {
0
}
}
struct HasPrivateIsEmpty;
impl HasPrivateIsEmpty {
pub fn len(self: &Self) -> isize {
1
}
fn is_empty(self: &Self) -> bool {
false
}
}
pub struct HasIsEmpty;
impl HasIsEmpty {
pub fn len(self: &Self) -> isize { //~ERROR item `HasIsEmpty` has a public `len` method but a private `is_empty`
1
}
fn is_empty(self: &Self) -> bool {
false
}
}
struct Wither;
pub trait WithIsEmpty {
fn len(self: &Self) -> isize;
fn is_empty(self: &Self) -> bool;
}
impl WithIsEmpty for Wither {
fn len(self: &Self) -> isize {
1
}
fn is_empty(self: &Self) -> bool {
false
}
}
pub struct HasWrongIsEmpty;
impl HasWrongIsEmpty {
pub fn len(self: &Self) -> isize { //~ERROR item `HasWrongIsEmpty` has a public `len` method but no corresponding `is_empty`
1
}
pub fn is_empty(self: &Self, x : u32) -> bool {
false
}
}
fn main() {
let x = [1, 2];
if x.len() == 0 {
//~^ERROR length comparison to zero
//~|HELP consider using `is_empty`
//~|SUGGESTION x.is_empty()
println!("This should not happen!");
}
if "".len() == 0 {
//~^ERROR length comparison to zero
//~|HELP consider using `is_empty`
//~|SUGGESTION "".is_empty()
}
let y = One;
if y.len() == 0 { //no error because One does not have .is_empty()
println!("This should not happen either!");
}
let z : &TraitsToo = &y;
if z.len() > 0 { //no error, because TraitsToo has no .is_empty() method
println!("Nor should this!");
}
let has_is_empty = HasIsEmpty;
if has_is_empty.len() == 0 {
//~^ERROR length comparison to zero
//~|HELP consider using `is_empty`
//~|SUGGESTION has_is_empty.is_empty()
println!("Or this!");
}
if has_is_empty.len() != 0 {
//~^ERROR length comparison to zero
//~|HELP consider using `is_empty`
//~|SUGGESTION !has_is_empty.is_empty()
println!("Or this!");
}
if has_is_empty.len() > 0 {
//~^ERROR length comparison to zero
//~|HELP consider using `is_empty`
//~|SUGGESTION !has_is_empty.is_empty()
println!("Or this!");
}
assert!(!has_is_empty.is_empty());
let with_is_empty: &WithIsEmpty = &Wither;
if with_is_empty.len() == 0 {
//~^ERROR length comparison to zero
//~|HELP consider using `is_empty`
//~|SUGGESTION with_is_empty.is_empty()
println!("Or this!");
}
assert!(!with_is_empty.is_empty());
let has_wrong_is_empty = HasWrongIsEmpty;
if has_wrong_is_empty.len() == 0 { //no error as HasWrongIsEmpty does not have .is_empty()
println!("Or this!");
}
}