src/tools/clippy/tests/ui/methods.rs

   1
   2 #![feature(const_fn)]
   3
   4 #![warn(clippy, clippy_pedantic)]
   5 #![allow(blacklisted_name, unused, print_stdout, non_ascii_literal, new_without_default,
   6     new_without_default_derive, missing_docs_in_private_items, needless_pass_by_value)]
   7
   8 use std::collections::BTreeMap;
   9 use std::collections::HashMap;
  10 use std::collections::HashSet;
  11 use std::collections::VecDeque;
  12 use std::ops::Mul;
  13 use std::iter::FromIterator;
  14 use std::rc::{self, Rc};
  15 use std::sync::{self, Arc};
  16
  17 pub struct T;
  18
  19 impl T {
  20     pub fn add(self, other: T) -> T { self }
  21
  22     pub(crate) fn drop(&mut self) { } // no error, not public interfact
  23     fn neg(self) -> Self { self } // no error, private function
  24     fn eq(&self, other: T) -> bool { true } // no error, private function
  25
  26     fn sub(&self, other: T) -> &T { self } // no error, self is a ref
  27     fn div(self) -> T { self } // no error, different #arguments
  28     fn rem(self, other: T) { } // no error, wrong return type
  29
  30     fn into_u32(self) -> u32 { 0 } // fine
  31     fn into_u16(&self) -> u16 { 0 }
  32
  33     fn to_something(self) -> u32 { 0 }
  34
  35     fn new(self) {}
  36 }
  37
  38 struct Lt<'a> {
  39     foo: &'a u32,
  40 }
  41
  42 impl<'a> Lt<'a> {
  43     // The lifetime is different, but that’s irrelevant, see #734
  44     #[allow(needless_lifetimes)]
  45     pub fn new<'b>(s: &'b str) -> Lt<'b> { unimplemented!() }
  46 }
  47
  48 struct Lt2<'a> {
  49     foo: &'a u32,
  50 }
  51
  52 impl<'a> Lt2<'a> {
  53     // The lifetime is different, but that’s irrelevant, see #734
  54     pub fn new(s: &str) -> Lt2 { unimplemented!() }
  55 }
  56
  57 struct Lt3<'a> {
  58     foo: &'a u32,
  59 }
  60
  61 impl<'a> Lt3<'a> {
  62     // The lifetime is different, but that’s irrelevant, see #734
  63     pub fn new() -> Lt3<'static> { unimplemented!() }
  64 }
  65
  66 #[derive(Clone,Copy)]
  67 struct U;
  68
  69 impl U {
  70     fn new() -> Self { U }
  71     fn to_something(self) -> u32 { 0 } // ok because U is Copy
  72 }
  73
  74 struct V<T> {
  75     _dummy: T
  76 }
  77
  78 impl<T> V<T> {
  79     fn new() -> Option<V<T>> { None }
  80 }
  81
  82 impl Mul<T> for T {
  83     type Output = T;
  84     fn mul(self, other: T) -> T { self } // no error, obviously
  85 }
  86
  87 /// Utility macro to test linting behavior in `option_methods()`
  88 /// The lints included in `option_methods()` should not lint if the call to map is partially
  89 /// within a macro
  90 macro_rules! opt_map {
  91     ($opt:expr, $map:expr) => {($opt).map($map)};
  92 }
  93
  94 /// Checks implementation of the following lints:
  95 /// * `OPTION_MAP_UNWRAP_OR`
  96 /// * `OPTION_MAP_UNWRAP_OR_ELSE`
  97 /// * `OPTION_MAP_OR_NONE`
  98 fn option_methods() {
  99     let opt = Some(1);
 100
 101     // Check OPTION_MAP_UNWRAP_OR
 102     // single line case
 103     let _ = opt.map(|x| x + 1)
 104
 105                .unwrap_or(0); // should lint even though this call is on a separate line
 106     // multi line cases
 107     let _ = opt.map(|x| {
 108                         x + 1
 109                     }
 110               ).unwrap_or(0);
 111     let _ = opt.map(|x| x + 1)
 112                .unwrap_or({
 113                     0
 114                 });
 115     // single line `map(f).unwrap_or(None)` case
 116     let _ = opt.map(|x| Some(x + 1)).unwrap_or(None);
 117     // multiline `map(f).unwrap_or(None)` cases
 118     let _ = opt.map(|x| {
 119         Some(x + 1)
 120     }
 121     ).unwrap_or(None);
 122     let _ = opt
 123         .map(|x| Some(x + 1))
 124         .unwrap_or(None);
 125     // macro case
 126     let _ = opt_map!(opt, |x| x + 1).unwrap_or(0); // should not lint
 127
 128     // Check OPTION_MAP_UNWRAP_OR_ELSE
 129     // single line case
 130     let _ = opt.map(|x| x + 1)
 131
 132                .unwrap_or_else(|| 0); // should lint even though this call is on a separate line
 133     // multi line cases
 134     let _ = opt.map(|x| {
 135                         x + 1
 136                     }
 137               ).unwrap_or_else(|| 0);
 138     let _ = opt.map(|x| x + 1)
 139                .unwrap_or_else(||
 140                     0
 141                 );
 142     // macro case
 143     let _ = opt_map!(opt, |x| x + 1).unwrap_or_else(|| 0); // should not lint
 144
 145     // Check OPTION_MAP_OR_NONE
 146     // single line case
 147     let _ = opt.map_or(None, |x| Some(x + 1));
 148     // multi line case
 149     let _ = opt.map_or(None, |x| {
 150                         Some(x + 1)
 151                        }
 152                 );
 153 }
 154
 155 /// Checks implementation of the following lints:
 156 /// * `RESULT_MAP_UNWRAP_OR_ELSE`
 157 fn result_methods() {
 158     let res: Result<i32, ()> = Ok(1);
 159
 160     // Check RESULT_MAP_UNWRAP_OR_ELSE
 161     // single line case
 162     let _ = res.map(|x| x + 1)
 163
 164                .unwrap_or_else(|e| 0); // should lint even though this call is on a separate line
 165     // multi line cases
 166     let _ = res.map(|x| {
 167                         x + 1
 168                     }
 169               ).unwrap_or_else(|e| 0);
 170     let _ = res.map(|x| x + 1)
 171                .unwrap_or_else(|e|
 172                     0
 173                 );
 174     // macro case
 175     let _ = opt_map!(res, |x| x + 1).unwrap_or_else(|e| 0); // should not lint
 176 }
 177
 178 /// Struct to generate false positives for things with .iter()
 179 #[derive(Copy, Clone)]
 180 struct HasIter;
 181
 182 impl HasIter {
 183     fn iter(self) -> IteratorFalsePositives {
 184         IteratorFalsePositives { foo: 0 }
 185     }
 186
 187     fn iter_mut(self) -> IteratorFalsePositives {
 188         IteratorFalsePositives { foo: 0 }
 189     }
 190 }
 191
 192 /// Struct to generate false positive for Iterator-based lints
 193 #[derive(Copy, Clone)]
 194 struct IteratorFalsePositives {
 195     foo: u32,
 196 }
 197
 198 impl IteratorFalsePositives {
 199     fn filter(self) -> IteratorFalsePositives {
 200         self
 201     }
 202
 203     fn next(self) -> IteratorFalsePositives {
 204         self
 205     }
 206
 207     fn find(self) -> Option<u32> {
 208         Some(self.foo)
 209     }
 210
 211     fn position(self) -> Option<u32> {
 212         Some(self.foo)
 213     }
 214
 215     fn rposition(self) -> Option<u32> {
 216         Some(self.foo)
 217     }
 218
 219     fn nth(self, n: usize) -> Option<u32> {
 220         Some(self.foo)
 221     }
 222
 223     fn skip(self, _: usize) -> IteratorFalsePositives {
 224         self
 225     }
 226 }
 227
 228 /// Checks implementation of `FILTER_NEXT` lint
 229 fn filter_next() {
 230     let v = vec![3, 2, 1, 0, -1, -2, -3];
 231
 232     // check single-line case
 233     let _ = v.iter().filter(|&x| *x < 0).next();
 234
 235     // check multi-line case
 236     let _ = v.iter().filter(|&x| {
 237                                 *x < 0
 238                             }
 239                    ).next();
 240
 241     // check that we don't lint if the caller is not an Iterator
 242     let foo = IteratorFalsePositives { foo: 0 };
 243     let _ = foo.filter().next();
 244 }
 245
 246 /// Checks implementation of `SEARCH_IS_SOME` lint
 247 fn search_is_some() {
 248     let v = vec![3, 2, 1, 0, -1, -2, -3];
 249
 250     // check `find().is_some()`, single-line
 251     let _ = v.iter().find(|&x| *x < 0).is_some();
 252
 253     // check `find().is_some()`, multi-line
 254     let _ = v.iter().find(|&x| {
 255                               *x < 0
 256                           }
 257                    ).is_some();
 258
 259     // check `position().is_some()`, single-line
 260     let _ = v.iter().position(|&x| x < 0).is_some();
 261
 262     // check `position().is_some()`, multi-line
 263     let _ = v.iter().position(|&x| {
 264                                   x < 0
 265                               }
 266                    ).is_some();
 267
 268     // check `rposition().is_some()`, single-line
 269     let _ = v.iter().rposition(|&x| x < 0).is_some();
 270
 271     // check `rposition().is_some()`, multi-line
 272     let _ = v.iter().rposition(|&x| {
 273                                    x < 0
 274                                }
 275                    ).is_some();
 276
 277     // check that we don't lint if the caller is not an Iterator
 278     let foo = IteratorFalsePositives { foo: 0 };
 279     let _ = foo.find().is_some();
 280     let _ = foo.position().is_some();
 281     let _ = foo.rposition().is_some();
 282 }
 283
 284 /// Checks implementation of the `OR_FUN_CALL` lint
 285 fn or_fun_call() {
 286     struct Foo;
 287
 288     impl Foo {
 289         fn new() -> Foo { Foo }
 290     }
 291
 292     enum Enum {
 293         A(i32),
 294     }
 295
 296     const fn make_const(i: i32) -> i32 { i }
 297
 298     fn make<T>() -> T { unimplemented!(); }
 299
 300     let with_enum = Some(Enum::A(1));
 301     with_enum.unwrap_or(Enum::A(5));
 302
 303     let with_const_fn = Some(1);
 304     with_const_fn.unwrap_or(make_const(5));
 305
 306     let with_constructor = Some(vec![1]);
 307     with_constructor.unwrap_or(make());
 308
 309     let with_new = Some(vec![1]);
 310     with_new.unwrap_or(Vec::new());
 311
 312     let with_const_args = Some(vec![1]);
 313     with_const_args.unwrap_or(Vec::with_capacity(12));
 314
 315     let with_err : Result<_, ()> = Ok(vec![1]);
 316     with_err.unwrap_or(make());
 317
 318     let with_err_args : Result<_, ()> = Ok(vec![1]);
 319     with_err_args.unwrap_or(Vec::with_capacity(12));
 320
 321     let with_default_trait = Some(1);
 322     with_default_trait.unwrap_or(Default::default());
 323
 324     let with_default_type = Some(1);
 325     with_default_type.unwrap_or(u64::default());
 326
 327     let with_vec = Some(vec![1]);
 328     with_vec.unwrap_or(vec![]);
 329
 330     // FIXME #944: ~|SUGGESTION with_vec.unwrap_or_else(|| vec![]);
 331
 332     let without_default = Some(Foo);
 333     without_default.unwrap_or(Foo::new());
 334
 335     let mut map = HashMap::<u64, String>::new();
 336     map.entry(42).or_insert(String::new());
 337
 338     let mut btree = BTreeMap::<u64, String>::new();
 339     btree.entry(42).or_insert(String::new());
 340
 341     let stringy = Some(String::from(""));
 342     let _ = stringy.unwrap_or("".to_owned());
 343 }
 344
 345 /// Checks implementation of `ITER_NTH` lint
 346 fn iter_nth() {
 347     let mut some_vec = vec![0, 1, 2, 3];
 348     let mut boxed_slice: Box<[u8]> = Box::new([0, 1, 2, 3]);
 349     let mut some_vec_deque: VecDeque<_> = some_vec.iter().cloned().collect();
 350
 351     {
 352         // Make sure we lint `.iter()` for relevant types
 353         let bad_vec = some_vec.iter().nth(3);
 354         let bad_slice = &some_vec[..].iter().nth(3);
 355         let bad_boxed_slice = boxed_slice.iter().nth(3);
 356         let bad_vec_deque = some_vec_deque.iter().nth(3);
 357     }
 358
 359     {
 360         // Make sure we lint `.iter_mut()` for relevant types
 361         let bad_vec = some_vec.iter_mut().nth(3);
 362     }
 363     {
 364         let bad_slice = &some_vec[..].iter_mut().nth(3);
 365     }
 366     {
 367         let bad_vec_deque = some_vec_deque.iter_mut().nth(3);
 368     }
 369
 370     // Make sure we don't lint for non-relevant types
 371     let false_positive = HasIter;
 372     let ok = false_positive.iter().nth(3);
 373     let ok_mut = false_positive.iter_mut().nth(3);
 374 }
 375
 376 /// Checks implementation of `ITER_SKIP_NEXT` lint
 377 fn iter_skip_next() {
 378     let mut some_vec = vec![0, 1, 2, 3];
 379     let _ = some_vec.iter().skip(42).next();
 380     let _ = some_vec.iter().cycle().skip(42).next();
 381     let _ = (1..10).skip(10).next();
 382     let _ = &some_vec[..].iter().skip(3).next();
 383     let foo = IteratorFalsePositives { foo : 0 };
 384     let _ = foo.skip(42).next();
 385     let _ = foo.filter().skip(42).next();
 386 }
 387
 388 #[allow(similar_names)]
 389 fn main() {
 390     let opt = Some(0);
 391     let _ = opt.unwrap();
 392 }