rust/tests/ui/methods.rs
f001 98aa0db0ac Add a lint for slice.iter().cloned().collect()
If one uses `slice.iter().cloned().collect()` to create a new `Vec`,
it should be `slice.to_owned()`.

Fix #1292
2017-02-12 17:03:09 +08:00

697 lines
13 KiB
Rust
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#![feature(plugin)]
#![feature(const_fn)]
#![plugin(clippy)]
#![deny(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/Manishearth/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();
}