/
methods.rs
463 lines (390 loc) · 14.7 KB
/
methods.rs
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#![feature(plugin)]
#![plugin(clippy)]
#![deny(clippy, clippy_pedantic)]
#![allow(blacklisted_name, unused, print_stdout, non_ascii_literal, new_without_default)]
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
fn new(self) {}
//~^ ERROR methods called `new` usually take no self
//~| ERROR methods called `new` usually return `Self`
}
struct Lt<'a> {
foo: &'a u32,
}
impl<'a> Lt<'a> {
// The lifetime is different, but that’s 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 that’s irrelevant, see #734
pub fn new(s: &str) -> Lt2 { 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) //~ 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);
}
#[allow(similar_names)]
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
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!");
let res3: Result<u32, MyErrorWithParam<u8>>= Ok(0);
res3.ok().expect("whoof"); //~ERROR called `ok().expect()`
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`
//~| HELP try this
//~| SUGGESTION v.extend_from_slice(&vec!["Some", "more"]);
v.extend(vec!["And", "even", "more"].iter()); //~ERROR use of `extend`
let o : Option<&'static str> = None;
v.extend(o);
v.extend(Some("Bye"));
v.extend(vec!["Not", "like", "this"]);
v.extend(["But", "this"].iter());
//~^ERROR use of `extend
//~| HELP try this
//~| SUGGESTION v.extend_from_slice(&["But", "this"]);
}
fn clone_on_copy() {
42.clone(); //~ERROR using `clone` on a `Copy` type
vec![1].clone(); // ok, not a Copy type
Some(vec![1]).clone(); // ok, not a Copy type
}
fn clone_on_copy_generic<T: Copy>(t: T) {
t.clone(); //~ERROR using `clone` on a `Copy` type
Some(t).clone(); //~ERROR using `clone` on a `Copy` type
}
fn clone_on_double_ref() {
let x = vec![1];
let y = &&x;
let z: &Vec<_> = y.clone(); //~ERROR using `clone` on a double
//~| HELP try dereferencing it
//~| SUGGESTION let z: &Vec<_> = (*y).clone();
//~^^^ERROR using `clone` on a `Copy` type
println!("{:p} {:p}",*y, z);
}
fn single_char_pattern() {
let x = "foo";
x.split("x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION 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("ℝ");
x.split("💣");
// Can't use this lint for unicode code points which don't fit in a char
x.split("❤️");
x.contains("x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION x.contains('x');
x.starts_with("x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION x.starts_with('x');
x.ends_with("x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION x.ends_with('x');
x.find("x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION x.find('x');
x.rfind("x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION x.rfind('x');
x.rsplit("x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION x.rsplit('x');
x.split_terminator("x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION x.split_terminator('x');
x.rsplit_terminator("x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION x.rsplit_terminator('x');
x.splitn(0, "x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION x.splitn(0, 'x');
x.rsplitn(0, "x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION x.rsplitn(0, 'x');
x.matches("x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION x.matches('x');
x.rmatches("x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION x.rmatches('x');
x.match_indices("x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION x.match_indices('x');
x.rmatch_indices("x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION x.rmatch_indices('x');
x.trim_left_matches("x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION x.trim_left_matches('x');
x.trim_right_matches("x");
//~^ ERROR single-character string constant used as pattern
//~| HELP try using a char instead:
//~| SUGGESTION x.trim_right_matches('x');
}