rust/tests/compile-fail/methods.rs
Devon Hollowood 443e4556c2 Add lints suggesting map_or() and map_or_else()
In accordance with the latter lint, replace map().unwrap_or_else() in
src/mut_mut.rs with map_or_else()
2015-11-25 23:56:45 -08:00

124 lines
4.0 KiB
Rust

#![feature(plugin)]
#![plugin(clippy)]
#![allow(unused)]
#![deny(clippy, clippy_pedantic)]
use std::ops::Mul;
struct T;
impl T {
fn add(self, other: T) -> T { self } //~ERROR defining a method called `add`
fn drop(&mut self) { } //~ERROR defining a method called `drop`
fn sub(&self, other: T) -> &T { self } // no error, self is a ref
fn div(self) -> T { self } // no error, different #arguments
fn rem(self, other: T) { } // no error, wrong return type
fn into_u32(self) -> u32 { 0 } // fine
fn into_u16(&self) -> u16 { 0 } //~ERROR methods called `into_*` usually take self by value
fn to_something(self) -> u32 { 0 } //~ERROR methods called `to_*` usually take self by reference
}
#[derive(Clone,Copy)]
struct U;
impl U {
fn to_something(self) -> u32 { 0 } // ok because U is Copy
}
impl Mul<T> for T {
type Output = T;
fn mul(self, other: T) -> T { self } // no error, obviously
}
/// Utility macro to test linting behavior in `option_methods()`
/// The lints included in `option_methods()` should not lint if the call to map is partially
/// within a macro
macro_rules! opt_map {
($opt:expr, $map:expr) => {($opt).map($map)};
}
/// Checks implementation of the following lints:
/// OPTION_MAP_UNWRAP_OR
/// OPTION_MAP_UNWRAP_OR_ELSE
fn option_methods() {
let opt = Some(1);
// Check OPTION_MAP_UNWRAP_OR
// single line case
let _ = opt.map(|x| x + 1) //~ ERROR called `map(f).unwrap_or(a)`
//~| NOTE replace this
.unwrap_or(0); // should lint even though this call is on a separate line
// multi line cases
let _ = opt.map(|x| { //~ ERROR called `map(f).unwrap_or(a)`
x + 1
}
).unwrap_or(0);
let _ = opt.map(|x| x + 1) //~ ERROR called `map(f).unwrap_or(a)`
.unwrap_or({
0
});
// macro case
let _ = opt_map!(opt, |x| x + 1).unwrap_or(0); // should not lint
// Check OPTION_MAP_UNWRAP_OR_ELSE
// single line case
let _ = opt.map(|x| x + 1) //~ ERROR called `map(f).unwrap_or_else(g)`
//~| NOTE replace this
.unwrap_or_else(|| 0); // should lint even though this call is on a separate line
// multi line cases
let _ = opt.map(|x| { //~ ERROR called `map(f).unwrap_or_else(g)`
x + 1
}
).unwrap_or_else(|| 0);
let _ = opt.map(|x| x + 1) //~ ERROR called `map(f).unwrap_or_else(g)`
.unwrap_or_else(||
0
);
// macro case
let _ = opt_map!(opt, |x| x + 1).unwrap_or_else(|| 0); // should not lint
}
fn main() {
use std::io;
let opt = Some(0);
let _ = opt.unwrap(); //~ERROR used unwrap() on an Option
let res: Result<i32, ()> = Ok(0);
let _ = res.unwrap(); //~ERROR used unwrap() on a Result
let _ = "str".to_string(); //~ERROR `"str".to_owned()` is faster
let v = &"str";
let string = v.to_string(); //~ERROR `(*v).to_owned()` is faster
let _again = string.to_string(); //~ERROR `String.to_string()` is a no-op
res.ok().expect("disaster!"); //~ERROR called `ok().expect()`
// the following should not warn, since `expect` isn't implemented unless
// the error type implements `Debug`
let res2: Result<i32, MyError> = Ok(0);
res2.ok().expect("oh noes!");
// we currently don't warn if the error type has a type parameter
// (but it would be nice if we did)
let res3: Result<u32, MyErrorWithParam<u8>>= Ok(0);
res3.ok().expect("whoof");
let res4: Result<u32, io::Error> = Ok(0);
res4.ok().expect("argh"); //~ERROR called `ok().expect()`
let res5: io::Result<u32> = Ok(0);
res5.ok().expect("oops"); //~ERROR called `ok().expect()`
let res6: Result<u32, &str> = Ok(0);
res6.ok().expect("meh"); //~ERROR called `ok().expect()`
}
struct MyError(()); // doesn't implement Debug
#[derive(Debug)]
struct MyErrorWithParam<T> {
x: T
}