Auto merge of #4049 - airt:fix-4033-search_is_some, r=flip1995

Fix #4033 search_is_some

Fixes #4033.

Suggest `any(|x| ..)` instead of `any(|&x| ..)` for `find(|&x| ..).is_some()` (Lint [search_is_some](https://rust-lang.github.io/rust-clippy/master/index.html#search_is_some))

FnDecl of `find`:

```rust
fn find<P>(&mut self, mut p: P) -> Option<Self::Item> where
    P: FnMut(&Self::Item) -> bool
```

FnDecl of `any`:

```rust
fn any<F>(&mut self, mut f: F) -> bool where
    F: FnMut(Self::Item) -> bool
```

If match on `|&_|` in closure of `find`, only use `|_|` in the suggestion.

PS. It's the first time that I have used the `hir` API, please correct me if there is any mistake 😺
This commit is contained in:
bors 2019-05-02 08:45:02 +00:00
commit 8151a17422
2 changed files with 18 additions and 3 deletions

View File

@ -2059,6 +2059,19 @@ fn lint_search_is_some<'a, 'tcx>(
);
let search_snippet = snippet(cx, search_args[1].span, "..");
if search_snippet.lines().count() <= 1 {
// suggest `any(|x| ..)` instead of `any(|&x| ..)` for `find(|&x| ..).is_some()`
let any_search_snippet = if_chain! {
if search_method == "find";
if let hir::ExprKind::Closure(_, _, body_id, ..) = search_args[1].node;
let closure_body = cx.tcx.hir().body(body_id);
if let Some(closure_arg) = closure_body.arguments.get(0);
if let hir::PatKind::Ref(..) = closure_arg.pat.node;
then {
Some(search_snippet.replacen('&', "", 1))
} else {
None
}
};
// add note if not multi-line
span_note_and_lint(
cx,
@ -2067,8 +2080,10 @@ fn lint_search_is_some<'a, 'tcx>(
&msg,
expr.span,
&format!(
"replace `{0}({1}).is_some()` with `any({1})`",
search_method, search_snippet
"replace `{0}({1}).is_some()` with `any({2})`",
search_method,
search_snippet,
any_search_snippet.as_ref().map_or(&*search_snippet, String::as_str)
),
);
} else {

View File

@ -155,7 +155,7 @@ LL | let _ = v.iter().find(|&x| *x < 0).is_some();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: `-D clippy::search-is-some` implied by `-D warnings`
= note: replace `find(|&x| *x < 0).is_some()` with `any(|&x| *x < 0)`
= note: replace `find(|&x| *x < 0).is_some()` with `any(|x| *x < 0)`
error: called `is_some()` after searching an `Iterator` with find. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:236:13