rust-clippy/tests/ui/methods.rs

525 lines
13 KiB
Rust
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

#![feature(plugin)]
#![feature(const_fn)]
#![plugin(clippy)]
#![warn(clippy, clippy_pedantic)]
#![allow(blacklisted_name, unused, print_stdout, non_ascii_literal, new_without_default, new_without_default_derive, missing_docs_in_private_items)]
use std::collections::BTreeMap;
use std::collections::HashMap;
use std::collections::HashSet;
use std::collections::VecDeque;
use std::ops::Mul;
use std::iter::FromIterator;
struct T;
impl T {
fn add(self, other: T) -> T { self }
fn drop(&mut self) { }
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 }
fn to_something(self) -> u32 { 0 }
fn new(self) {}
}
struct Lt<'a> {
foo: &'a u32,
}
impl<'a> Lt<'a> {
// The lifetime is different, but thats irrelevant, see #734
#[allow(needless_lifetimes)]
pub fn new<'b>(s: &'b str) -> Lt<'b> { unimplemented!() }
}
struct Lt2<'a> {
foo: &'a u32,
}
impl<'a> Lt2<'a> {
// The lifetime is different, but thats irrelevant, see #734
pub fn new(s: &str) -> Lt2 { unimplemented!() }
}
struct Lt3<'a> {
foo: &'a u32,
}
impl<'a> Lt3<'a> {
// The lifetime is different, but thats irrelevant, see #734
pub fn new() -> Lt3<'static> { unimplemented!() }
}
#[derive(Clone,Copy)]
struct U;
impl U {
fn new() -> Self { U }
fn to_something(self) -> u32 { 0 } // ok because U is Copy
}
struct V<T> {
_dummy: T
}
impl<T> V<T> {
fn new() -> Option<V<T>> { None }
}
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)
.unwrap_or(0); // should lint even though this call is on a separate line
// multi line cases
let _ = opt.map(|x| {
x + 1
}
).unwrap_or(0);
let _ = opt.map(|x| x + 1)
.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)
.unwrap_or_else(|| 0); // should lint even though this call is on a separate line
// multi line cases
let _ = opt.map(|x| {
x + 1
}
).unwrap_or_else(|| 0);
let _ = opt.map(|x| x + 1)
.unwrap_or_else(||
0
);
// macro case
let _ = opt_map!(opt, |x| x + 1).unwrap_or_else(|| 0); // should not lint
}
/// Struct to generate false positives for things with .iter()
#[derive(Copy, Clone)]
struct HasIter;
impl HasIter {
fn iter(self) -> IteratorFalsePositives {
IteratorFalsePositives { foo: 0 }
}
fn iter_mut(self) -> IteratorFalsePositives {
IteratorFalsePositives { foo: 0 }
}
}
/// 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)
}
fn nth(self, n: usize) -> Option<u32> {
Some(self.foo)
}
fn skip(self, _: usize) -> IteratorFalsePositives {
self
}
}
#[derive(Copy, Clone)]
struct HasChars;
impl HasChars {
fn chars(self) -> std::str::Chars<'static> {
"HasChars".chars()
}
}
/// 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();
// check multi-line case
let _ = v.iter().filter(|&x| {
*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();
// check `find().is_some()`, multi-line
let _ = v.iter().find(|&x| {
*x < 0
}
).is_some();
// check `position().is_some()`, single-line
let _ = v.iter().position(|&x| x < 0).is_some();
// check `position().is_some()`, multi-line
let _ = v.iter().position(|&x| {
x < 0
}
).is_some();
// check `rposition().is_some()`, single-line
let _ = v.iter().rposition(|&x| x < 0).is_some();
// check `rposition().is_some()`, multi-line
let _ = v.iter().rposition(|&x| {
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 }
}
enum Enum {
A(i32),
}
const fn make_const(i: i32) -> i32 { i }
fn make<T>() -> T { unimplemented!(); }
let with_enum = Some(Enum::A(1));
with_enum.unwrap_or(Enum::A(5));
let with_const_fn = Some(1);
with_const_fn.unwrap_or(make_const(5));
let with_constructor = Some(vec![1]);
with_constructor.unwrap_or(make());
let with_new = Some(vec![1]);
with_new.unwrap_or(Vec::new());
let with_const_args = Some(vec![1]);
with_const_args.unwrap_or(Vec::with_capacity(12));
let with_err : Result<_, ()> = Ok(vec![1]);
with_err.unwrap_or(make());
let with_err_args : Result<_, ()> = Ok(vec![1]);
with_err_args.unwrap_or(Vec::with_capacity(12));
let with_default_trait = Some(1);
with_default_trait.unwrap_or(Default::default());
let with_default_type = Some(1);
with_default_type.unwrap_or(u64::default());
let with_vec = Some(vec![1]);
with_vec.unwrap_or(vec![]);
// FIXME #944: ~|SUGGESTION with_vec.unwrap_or_else(|| vec![]);
let without_default = Some(Foo);
without_default.unwrap_or(Foo::new());
let mut map = HashMap::<u64, String>::new();
map.entry(42).or_insert(String::new());
let mut btree = BTreeMap::<u64, String>::new();
btree.entry(42).or_insert(String::new());
let stringy = Some(String::from(""));
let _ = stringy.unwrap_or("".to_owned());
}
/// Checks implementation of `ITER_NTH` lint
fn iter_nth() {
let mut some_vec = vec![0, 1, 2, 3];
let mut boxed_slice: Box<[u8]> = Box::new([0, 1, 2, 3]);
let mut some_vec_deque: VecDeque<_> = some_vec.iter().cloned().collect();
{
// Make sure we lint `.iter()` for relevant types
let bad_vec = some_vec.iter().nth(3);
let bad_slice = &some_vec[..].iter().nth(3);
let bad_boxed_slice = boxed_slice.iter().nth(3);
let bad_vec_deque = some_vec_deque.iter().nth(3);
}
{
// Make sure we lint `.iter_mut()` for relevant types
let bad_vec = some_vec.iter_mut().nth(3);
}
{
let bad_slice = &some_vec[..].iter_mut().nth(3);
}
{
let bad_vec_deque = some_vec_deque.iter_mut().nth(3);
}
// Make sure we don't lint for non-relevant types
let false_positive = HasIter;
let ok = false_positive.iter().nth(3);
let ok_mut = false_positive.iter_mut().nth(3);
}
/// Checks implementation of `ITER_SKIP_NEXT` lint
fn iter_skip_next() {
let mut some_vec = vec![0, 1, 2, 3];
let _ = some_vec.iter().skip(42).next();
let _ = some_vec.iter().cycle().skip(42).next();
let _ = (1..10).skip(10).next();
let _ = &some_vec[..].iter().skip(3).next();
let foo = IteratorFalsePositives { foo : 0 };
let _ = foo.skip(42).next();
let _ = foo.filter().skip(42).next();
}
struct GetFalsePositive {
arr: [u32; 3],
}
impl GetFalsePositive {
fn get(&self, pos: usize) -> Option<&u32> { self.arr.get(pos) }
fn get_mut(&mut self, pos: usize) -> Option<&mut u32> { self.arr.get_mut(pos) }
}
/// Checks implementation of `GET_UNWRAP` lint
fn get_unwrap() {
let mut boxed_slice: Box<[u8]> = Box::new([0, 1, 2, 3]);
let mut some_slice = &mut [0, 1, 2, 3];
let mut some_vec = vec![0, 1, 2, 3];
let mut some_vecdeque: VecDeque<_> = some_vec.iter().cloned().collect();
let mut some_hashmap: HashMap<u8, char> = HashMap::from_iter(vec![(1, 'a'), (2, 'b')]);
let mut some_btreemap: BTreeMap<u8, char> = BTreeMap::from_iter(vec![(1, 'a'), (2, 'b')]);
let mut false_positive = GetFalsePositive { arr: [0, 1, 2] };
{ // Test `get().unwrap()`
let _ = boxed_slice.get(1).unwrap();
let _ = some_slice.get(0).unwrap();
let _ = some_vec.get(0).unwrap();
let _ = some_vecdeque.get(0).unwrap();
let _ = some_hashmap.get(&1).unwrap();
let _ = some_btreemap.get(&1).unwrap();
let _ = false_positive.get(0).unwrap();
}
{ // Test `get_mut().unwrap()`
*boxed_slice.get_mut(0).unwrap() = 1;
*some_slice.get_mut(0).unwrap() = 1;
*some_vec.get_mut(0).unwrap() = 1;
*some_vecdeque.get_mut(0).unwrap() = 1;
// Check false positives
*some_hashmap.get_mut(&1).unwrap() = 'b';
*some_btreemap.get_mut(&1).unwrap() = 'b';
*false_positive.get_mut(0).unwrap() = 1;
}
}
#[allow(similar_names)]
fn main() {
use std::io;
let opt = Some(0);
let _ = opt.unwrap();
let res: Result<i32, ()> = Ok(0);
let _ = res.unwrap();
res.ok().expect("disaster!");
// 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!");
let res3: Result<u32, MyErrorWithParam<u8>>= Ok(0);
res3.ok().expect("whoof");
let res4: Result<u32, io::Error> = Ok(0);
res4.ok().expect("argh");
let res5: io::Result<u32> = Ok(0);
res5.ok().expect("oops");
let res6: Result<u32, &str> = Ok(0);
res6.ok().expect("meh");
}
struct MyError(()); // doesn't implement Debug
#[derive(Debug)]
struct MyErrorWithParam<T> {
x: T
}
#[allow(unnecessary_operation)]
fn starts_with() {
"".chars().next() == Some(' ');
Some(' ') != "".chars().next();
}
fn str_extend_chars() {
let abc = "abc";
let def = String::from("def");
let mut s = String::new();
s.push_str(abc);
s.extend(abc.chars());
s.push_str("abc");
s.extend("abc".chars());
s.push_str(&def);
s.extend(def.chars());
s.extend(abc.chars().skip(1));
s.extend("abc".chars().skip(1));
s.extend(['a', 'b', 'c'].iter());
let f = HasChars;
s.extend(f.chars());
}
fn clone_on_copy() {
42.clone();
vec![1].clone(); // ok, not a Copy type
Some(vec![1]).clone(); // ok, not a Copy type
(&42).clone();
}
fn clone_on_copy_generic<T: Copy>(t: T) {
t.clone();
Some(t).clone();
}
fn clone_on_double_ref() {
let x = vec![1];
let y = &&x;
let z: &Vec<_> = y.clone();
println!("{:p} {:p}",*y, z);
}
fn single_char_pattern() {
let x = "foo";
x.split("x");
x.split("xx");
x.split('x');
let y = "x";
x.split(y);
// Not yet testing for multi-byte characters
// Changing `r.len() == 1` to `r.chars().count() == 1` in `lint_single_char_pattern`
// should have done this but produced an ICE
//
// We may not want to suggest changing these anyway
// See: https://github.com/rust-lang-nursery/rust-clippy/issues/650#issuecomment-184328984
x.split("ß");
x.split("");
x.split("💣");
// Can't use this lint for unicode code points which don't fit in a char
x.split("❤️");
x.contains("x");
x.starts_with("x");
x.ends_with("x");
x.find("x");
x.rfind("x");
x.rsplit("x");
x.split_terminator("x");
x.rsplit_terminator("x");
x.splitn(0, "x");
x.rsplitn(0, "x");
x.matches("x");
x.rmatches("x");
x.match_indices("x");
x.rmatch_indices("x");
x.trim_left_matches("x");
x.trim_right_matches("x");
let h = HashSet::<String>::new();
h.contains("X"); // should not warn
}
#[allow(result_unwrap_used)]
fn temporary_cstring() {
use std::ffi::CString;
CString::new("foo").unwrap().as_ptr();
}
fn iter_clone_collect() {
let v = [1,2,3,4,5];
let v2 : Vec<isize> = v.iter().cloned().collect();
let v3 : HashSet<isize> = v.iter().cloned().collect();
let v4 : VecDeque<isize> = v.iter().cloned().collect();
}