rust/tests/compile-fail/methods.rs

317 lines
9.9 KiB
Rust

#![feature(plugin)]
#![plugin(clippy)]
#![allow(unused)]
#![deny(clippy, clippy_pedantic)]
use std::collections::BTreeMap;
use std::collections::HashMap;
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 `map(|x| x + 1).unwrap_or(0)`
.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 `map(|x| x + 1).unwrap_or_else(|| 0)`
.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
}
/// Struct to generate false positive for Iterator-based lints
#[derive(Copy, Clone)]
struct IteratorFalsePositives {
foo: u32,
}
impl IteratorFalsePositives {
fn filter(self) -> IteratorFalsePositives {
self
}
fn next(self) -> IteratorFalsePositives {
self
}
fn find(self) -> Option<u32> {
Some(self.foo)
}
fn position(self) -> Option<u32> {
Some(self.foo)
}
fn rposition(self) -> Option<u32> {
Some(self.foo)
}
}
/// Checks implementation of FILTER_NEXT lint
fn filter_next() {
let v = vec![3, 2, 1, 0, -1, -2, -3];
// check single-line case
let _ = v.iter().filter(|&x| *x < 0).next();
//~^ ERROR called `filter(p).next()` on an Iterator.
//~| NOTE replace `filter(|&x| *x < 0).next()`
// check multi-line case
let _ = v.iter().filter(|&x| { //~ERROR called `filter(p).next()` on an Iterator.
*x < 0
}
).next();
// check that we don't lint if the caller is not an Iterator
let foo = IteratorFalsePositives { foo: 0 };
let _ = foo.filter().next();
}
/// Checks implementation of SEARCH_IS_SOME lint
fn search_is_some() {
let v = vec![3, 2, 1, 0, -1, -2, -3];
// check `find().is_some()`, single-line
let _ = v.iter().find(|&x| *x < 0).is_some();
//~^ ERROR called `is_some()` after searching
//~| NOTE replace `find(|&x| *x < 0).is_some()`
// check `find().is_some()`, multi-line
let _ = v.iter().find(|&x| { //~ERROR called `is_some()` after searching
*x < 0
}
).is_some();
// check `position().is_some()`, single-line
let _ = v.iter().position(|&x| x < 0).is_some();
//~^ ERROR called `is_some()` after searching
//~| NOTE replace `position(|&x| x < 0).is_some()`
// check `position().is_some()`, multi-line
let _ = v.iter().position(|&x| { //~ERROR called `is_some()` after searching
x < 0
}
).is_some();
// check `rposition().is_some()`, single-line
let _ = v.iter().rposition(|&x| x < 0).is_some();
//~^ ERROR called `is_some()` after searching
//~| NOTE replace `rposition(|&x| x < 0).is_some()`
// check `rposition().is_some()`, multi-line
let _ = v.iter().rposition(|&x| { //~ERROR called `is_some()` after searching
x < 0
}
).is_some();
// check that we don't lint if the caller is not an Iterator
let foo = IteratorFalsePositives { foo: 0 };
let _ = foo.find().is_some();
let _ = foo.position().is_some();
let _ = foo.rposition().is_some();
}
/// Checks implementation of the OR_FUN_CALL lint
fn or_fun_call() {
struct Foo;
impl Foo {
fn new() -> Foo { Foo }
}
fn make<T>() -> T { unimplemented!(); }
let with_constructor = Some(vec![1]);
with_constructor.unwrap_or(make());
//~^ERROR use of `unwrap_or`
//~|HELP try this
//~|SUGGESTION with_constructor.unwrap_or_else(make)
let with_new = Some(vec![1]);
with_new.unwrap_or(Vec::new());
//~^ERROR use of `unwrap_or`
//~|HELP try this
//~|SUGGESTION with_new.unwrap_or_default();
let with_const_args = Some(vec![1]);
with_const_args.unwrap_or(Vec::with_capacity(12));
//~^ERROR use of `unwrap_or`
//~|HELP try this
//~|SUGGESTION with_const_args.unwrap_or_else(|| Vec::with_capacity(12));
let with_err : Result<_, ()> = Ok(vec![1]);
with_err.unwrap_or(make());
//~^ERROR use of `unwrap_or`
//~|HELP try this
//~|SUGGESTION with_err.unwrap_or_else(|_| make());
let with_err_args : Result<_, ()> = Ok(vec![1]);
with_err_args.unwrap_or(Vec::with_capacity(12));
//~^ERROR use of `unwrap_or`
//~|HELP try this
//~|SUGGESTION with_err_args.unwrap_or_else(|_| Vec::with_capacity(12));
let with_default_trait = Some(1);
with_default_trait.unwrap_or(Default::default());
//~^ERROR use of `unwrap_or`
//~|HELP try this
//~|SUGGESTION with_default_trait.unwrap_or_default();
let with_default_type = Some(1);
with_default_type.unwrap_or(u64::default());
//~^ERROR use of `unwrap_or`
//~|HELP try this
//~|SUGGESTION with_default_type.unwrap_or_default();
let with_vec = Some(vec![1]);
with_vec.unwrap_or(vec![]);
//~^ERROR use of `unwrap_or`
//~|HELP try this
//~|SUGGESTION with_vec.unwrap_or_else(|| vec![]);
let without_default = Some(Foo);
without_default.unwrap_or(Foo::new());
//~^ERROR use of `unwrap_or`
//~|HELP try this
//~|SUGGESTION without_default.unwrap_or_else(Foo::new);
let mut map = HashMap::<u64, String>::new();
map.entry(42).or_insert(String::new());
//~^ERROR use of `or_insert` followed by a function call
//~|HELP try this
//~|SUGGESTION map.entry(42).or_insert_with(String::new);
let mut btree = BTreeMap::<u64, String>::new();
btree.entry(42).or_insert(String::new());
//~^ERROR use of `or_insert` followed by a function call
//~|HELP try this
//~|SUGGESTION btree.entry(42).or_insert_with(String::new);
}
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
}
fn starts_with() {
"".chars().next() == Some(' ');
//~^ ERROR starts_with
//~| HELP like this
//~| SUGGESTION "".starts_with(' ')
Some(' ') != "".chars().next();
//~^ ERROR starts_with
//~| HELP like this
//~| SUGGESTION !"".starts_with(' ')
}
fn use_extend_from_slice() {
let mut v : Vec<&'static str> = vec![];
v.extend(&["Hello", "World"]); //~ERROR use of `extend`
v.extend(vec!["Some", "more"]); //~ERROR use of `extend`
v.extend(vec!["And", "even", "more"].iter()); //~ERROR use of `extend`
let o : Option<&'static str> = None;
v.extend(o);
v.extend(Some("Bye"));
}