diff --git a/clippy_lints/src/eta_reduction.rs b/clippy_lints/src/eta_reduction.rs index 4a93101d7cb..b12e3167997 100644 --- a/clippy_lints/src/eta_reduction.rs +++ b/clippy_lints/src/eta_reduction.rs @@ -82,6 +82,8 @@ fn check_closure(cx: &LateContext<'_, '_>, expr: &Expr) { if_chain!( if let ExprKind::Call(ref caller, ref args) = ex.node; + if let ExprKind::Path(_) = caller.node; + // Not the same number of arguments, there is no way the closure is the same as the function return; if args.len() == decl.inputs.len(); diff --git a/tests/ui/eta.fixed b/tests/ui/eta.fixed index 1ad836d25ff..ca1ccad29f2 100644 --- a/tests/ui/eta.fixed +++ b/tests/ui/eta.fixed @@ -20,7 +20,7 @@ use std::path::PathBuf; fn main() { let a = Some(1u8).map(foo); meta(foo); - let c = Some(1u8).map({1+2; foo}); + let c = Some(1u8).map(|a| {1+2; foo}(a)); let d = Some(1u8).map(|a| foo((|b| foo2(b))(a))); //is adjusted? all(&[1, 2, 3], &2, |x, y| below(x, y)); //is adjusted unsafe { @@ -105,7 +105,7 @@ fn test_redundant_closures_containing_method_calls() { let mut some = Some(|x| x * x); let arr = [Ok(1), Err(2)]; - let _: Vec<_> = arr.iter().map(|x| x.map_err(some.take().unwrap())).collect(); + let _: Vec<_> = arr.iter().map(|x| x.map_err(|e| some.take().unwrap()(e))).collect(); } struct Thunk(Box T>); @@ -177,3 +177,10 @@ fn test_redundant_closure_with_another_closure() { let closure = |a| println!("{}", a); let a = Some(1u8).map(closure); } + +fn make_lazy(f: fn() -> fn(u8) -> u8) -> impl Fn(u8) -> u8 { + // Currently f is called when result of make_lazy is called. + // If the closure is removed, f will be called when make_lazy itself is + // called. This changes semantics, so the closure must stay. + Box::new(move |x| f()(x)) +} diff --git a/tests/ui/eta.rs b/tests/ui/eta.rs index 41a13d769a6..f736543dc1b 100644 --- a/tests/ui/eta.rs +++ b/tests/ui/eta.rs @@ -177,3 +177,10 @@ fn test_redundant_closure_with_another_closure() { let closure = |a| println!("{}", a); let a = Some(1u8).map(|a| closure(a)); } + +fn make_lazy(f: fn() -> fn(u8) -> u8) -> impl Fn(u8) -> u8 { + // Currently f is called when result of make_lazy is called. + // If the closure is removed, f will be called when make_lazy itself is + // called. This changes semantics, so the closure must stay. + Box::new(move |x| f()(x)) +} diff --git a/tests/ui/eta.stderr b/tests/ui/eta.stderr index ff402a1850e..d19d21eec0d 100644 --- a/tests/ui/eta.stderr +++ b/tests/ui/eta.stderr @@ -12,12 +12,6 @@ error: redundant closure found LL | meta(|a| foo(a)); | ^^^^^^^^^^ help: remove closure as shown: `foo` -error: redundant closure found - --> $DIR/eta.rs:23:27 - | -LL | let c = Some(1u8).map(|a| {1+2; foo}(a)); - | ^^^^^^^^^^^^^^^^^ help: remove closure as shown: `{1+2; foo}` - error: this expression borrows a reference that is immediately dereferenced by the compiler --> $DIR/eta.rs:25:21 | @@ -70,12 +64,6 @@ error: redundant closure found LL | let e: std::vec::Vec = vec!['a', 'b', 'c'].iter().map(|c| c.to_ascii_uppercase()).collect(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove closure as shown: `char::to_ascii_uppercase` -error: redundant closure found - --> $DIR/eta.rs:108:50 - | -LL | let _: Vec<_> = arr.iter().map(|x| x.map_err(|e| some.take().unwrap()(e))).collect(); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove closure as shown: `some.take().unwrap()` - error: redundant closure found --> $DIR/eta.rs:173:27 | @@ -88,5 +76,5 @@ error: redundant closure found LL | let a = Some(1u8).map(|a| closure(a)); | ^^^^^^^^^^^^^^ help: remove closure as shown: `closure` -error: aborting due to 14 previous errors +error: aborting due to 12 previous errors