1 files changed, 204 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/eta.fixed b/src/tools/clippy/tests/ui/eta.fixed
new file mode 100644
index 00000000000..1b34c2f74eb
--- /dev/null
+++ b/src/tools/clippy/tests/ui/eta.fixed
@@ -0,0 +1,204 @@
+// run-rustfix
+
+#![allow(
+    unused,
+    clippy::no_effect,
+    clippy::redundant_closure_call,
+    clippy::many_single_char_names,
+    clippy::needless_pass_by_value,
+    clippy::option_map_unit_fn
+)]
+#![warn(
+    clippy::redundant_closure,
+    clippy::redundant_closure_for_method_calls,
+    clippy::needless_borrow
+)]
+
+use std::path::PathBuf;
+
+fn main() {
+    let a = Some(1u8).map(foo);
+    meta(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 {
+        Some(1u8).map(|a| unsafe_fn(a)); // unsafe fn
+    }
+
+    // See #815
+    let e = Some(1u8).map(|a| divergent(a));
+    let e = Some(1u8).map(generic);
+    let e = Some(1u8).map(generic);
+    // See #515
+    let a: Option<Box<dyn (::std::ops::Deref<Target = [i32]>)>> =
+        Some(vec![1i32, 2]).map(|v| -> Box<dyn (::std::ops::Deref<Target = [i32]>)> { Box::new(v) });
+}
+
+trait TestTrait {
+    fn trait_foo(self) -> bool;
+    fn trait_foo_ref(&self) -> bool;
+}
+
+struct TestStruct<'a> {
+    some_ref: &'a i32,
+}
+
+impl<'a> TestStruct<'a> {
+    fn foo(self) -> bool {
+        false
+    }
+    unsafe fn foo_unsafe(self) -> bool {
+        true
+    }
+}
+
+impl<'a> TestTrait for TestStruct<'a> {
+    fn trait_foo(self) -> bool {
+        false
+    }
+    fn trait_foo_ref(&self) -> bool {
+        false
+    }
+}
+
+impl<'a> std::ops::Deref for TestStruct<'a> {
+    type Target = char;
+    fn deref(&self) -> &char {
+        &'a'
+    }
+}
+
+fn test_redundant_closures_containing_method_calls() {
+    let i = 10;
+    let e = Some(TestStruct { some_ref: &i }).map(TestStruct::foo);
+    let e = Some(TestStruct { some_ref: &i }).map(TestStruct::foo);
+    let e = Some(TestStruct { some_ref: &i }).map(TestTrait::trait_foo);
+    let e = Some(TestStruct { some_ref: &i }).map(|a| a.trait_foo_ref());
+    let e = Some(TestStruct { some_ref: &i }).map(TestTrait::trait_foo);
+    let e = Some(&mut vec![1, 2, 3]).map(std::vec::Vec::clear);
+    let e = Some(&mut vec![1, 2, 3]).map(std::vec::Vec::clear);
+    unsafe {
+        let e = Some(TestStruct { some_ref: &i }).map(|a| a.foo_unsafe());
+    }
+    let e = Some("str").map(std::string::ToString::to_string);
+    let e = Some("str").map(str::to_string);
+    let e = Some('a').map(char::to_uppercase);
+    let e = Some('a').map(char::to_uppercase);
+    let e: std::vec::Vec<usize> = vec!['a', 'b', 'c'].iter().map(|c| c.len_utf8()).collect();
+    let e: std::vec::Vec<char> = vec!['a', 'b', 'c'].iter().map(char::to_ascii_uppercase).collect();
+    let e: std::vec::Vec<char> = vec!['a', 'b', 'c'].iter().map(char::to_ascii_uppercase).collect();
+    let p = Some(PathBuf::new());
+    let e = p.as_ref().and_then(|s| s.to_str());
+    let c = Some(TestStruct { some_ref: &i })
+        .as_ref()
+        .map(|c| c.to_ascii_uppercase());
+
+    fn test_different_borrow_levels<T>(t: &[&T])
+    where
+        T: TestTrait,
+    {
+        t.iter().filter(|x| x.trait_foo_ref());
+        t.iter().map(|x| x.trait_foo_ref());
+    }
+
+    let mut some = Some(|x| x * x);
+    let arr = [Ok(1), Err(2)];
+    let _: Vec<_> = arr.iter().map(|x| x.map_err(|e| some.take().unwrap()(e))).collect();
+}
+
+struct Thunk<T>(Box<dyn FnMut() -> T>);
+
+impl<T> Thunk<T> {
+    fn new<F: 'static + FnOnce() -> T>(f: F) -> Thunk<T> {
+        let mut option = Some(f);
+        // This should not trigger redundant_closure (#1439)
+        Thunk(Box::new(move || option.take().unwrap()()))
+    }
+
+    fn unwrap(self) -> T {
+        let Thunk(mut f) = self;
+        f()
+    }
+}
+
+fn foobar() {
+    let thunk = Thunk::new(|| println!("Hello, world!"));
+    thunk.unwrap()
+}
+
+fn meta<F>(f: F)
+where
+    F: Fn(u8),
+{
+    f(1u8)
+}
+
+fn foo(_: u8) {}
+
+fn foo2(_: u8) -> u8 {
+    1u8
+}
+
+fn all<X, F>(x: &[X], y: &X, f: F) -> bool
+where
+    F: Fn(&X, &X) -> bool,
+{
+    x.iter().all(|e| f(e, y))
+}
+
+fn below(x: &u8, y: &u8) -> bool {
+    x < y
+}
+
+unsafe fn unsafe_fn(_: u8) {}
+
+fn divergent(_: u8) -> ! {
+    unimplemented!()
+}
+
+fn generic<T>(_: T) -> u8 {
+    0
+}
+
+fn passes_fn_mut(mut x: Box<dyn FnMut()>) {
+    requires_fn_once(|| x());
+}
+fn requires_fn_once<T: FnOnce()>(_: T) {}
+
+fn test_redundant_closure_with_function_pointer() {
+    type FnPtrType = fn(u8);
+    let foo_ptr: FnPtrType = foo;
+    let a = Some(1u8).map(foo_ptr);
+}
+
+fn test_redundant_closure_with_another_closure() {
+    let closure = |a| println!("{}", a);
+    let a = Some(1u8).map(closure);
+}
+
+fn make_lazy(f: impl 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))
+}
+
+fn call<F: FnOnce(&mut String) -> String>(f: F) -> String {
+    f(&mut "Hello".to_owned())
+}
+fn test_difference_in_mutability() {
+    call(|s| s.clone());
+}
+
+struct Bar;
+impl std::ops::Deref for Bar {
+    type Target = str;
+    fn deref(&self) -> &str {
+        "hi"
+    }
+}
+
+fn test_deref_with_trait_method() {
+    let _ = [Bar].iter().map(|s| s.to_string()).collect::<Vec<_>>();
+}