Auto merge of #3933 - phansch:add_rustfix_eta, r=oli-obk

Add // run-rustfix for eta.rs test

cc #3071, #3630

tests/ui/eta.fixed

@@ -0,0 +1,135 @@
+// 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,
+    clippy::trivially_copy_pass_by_ref
+)]
+#![warn(clippy::redundant_closure, clippy::needless_borrow)]
+
+use std::path::PathBuf;
+
+fn main() {
+    let a = Some(1u8).map(foo);
+    meta(foo);
+    let c = Some(1u8).map({1+2; foo});
+    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<::std::ops::Deref<Target = [i32]>>> =
+        Some(vec![1i32, 2]).map(|v| -> Box<::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());
+    }
+}
+
+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
+}

tests/ui/eta.rs

@@ -1,3 +1,5 @@
+// run-rustfix
+
 #![allow(
     unused,
     clippy::no_effect,

tests/ui/eta.stderr

@@ -1,69 +1,69 @@
 error: redundant closure found
-  --> $DIR/eta.rs:15:27
+  --> $DIR/eta.rs:17:27
    |
 LL |     let a = Some(1u8).map(|a| foo(a));
    |                           ^^^^^^^^^^ help: remove closure as shown: `foo`
    |
    = note: `-D clippy::redundant-closure` implied by `-D warnings`
 
 error: redundant closure found
-  --> $DIR/eta.rs:16:10
+  --> $DIR/eta.rs:18:10
    |
 LL |     meta(|a| foo(a));
    |          ^^^^^^^^^^ help: remove closure as shown: `foo`
 
 error: redundant closure found
-  --> $DIR/eta.rs:17:27
+  --> $DIR/eta.rs:19:27
    |
 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:19:21
+  --> $DIR/eta.rs:21:21
    |
 LL |     all(&[1, 2, 3], &&2, |x, y| below(x, y)); //is adjusted
    |                     ^^^ help: change this to: `&2`
    |
    = note: `-D clippy::needless-borrow` implied by `-D warnings`
 
 error: redundant closure found
-  --> $DIR/eta.rs:26:27
+  --> $DIR/eta.rs:28:27
    |
 LL |     let e = Some(1u8).map(|a| generic(a));
    |                           ^^^^^^^^^^^^^^ help: remove closure as shown: `generic`
 
 error: redundant closure found
-  --> $DIR/eta.rs:69:51
+  --> $DIR/eta.rs:71:51
    |
 LL |     let e = Some(TestStruct { some_ref: &i }).map(|a| a.foo());
    |                                                   ^^^^^^^^^^^ help: remove closure as shown: `TestStruct::foo`
 
 error: redundant closure found
-  --> $DIR/eta.rs:71:51
+  --> $DIR/eta.rs:73:51
    |
 LL |     let e = Some(TestStruct { some_ref: &i }).map(|a| a.trait_foo());
    |                                                   ^^^^^^^^^^^^^^^^^ help: remove closure as shown: `TestTrait::trait_foo`
 
 error: redundant closure found
-  --> $DIR/eta.rs:74:42
+  --> $DIR/eta.rs:76:42
    |
 LL |     let e = Some(&mut vec![1, 2, 3]).map(|v| v.clear());
    |                                          ^^^^^^^^^^^^^ help: remove closure as shown: `std::vec::Vec::clear`
 
 error: redundant closure found
-  --> $DIR/eta.rs:79:29
+  --> $DIR/eta.rs:81:29
    |
 LL |     let e = Some("str").map(|s| s.to_string());
    |                             ^^^^^^^^^^^^^^^^^ help: remove closure as shown: `std::string::ToString::to_string`
 
 error: redundant closure found
-  --> $DIR/eta.rs:81:27
+  --> $DIR/eta.rs:83:27
    |
 LL |     let e = Some('a').map(|s| s.to_uppercase());
    |                           ^^^^^^^^^^^^^^^^^^^^ help: remove closure as shown: `char::to_uppercase`
 
 error: redundant closure found
-  --> $DIR/eta.rs:84:65
+  --> $DIR/eta.rs:86:65
    |
 LL |     let e: std::vec::Vec<char> = vec!['a', 'b', 'c'].iter().map(|c| c.to_ascii_uppercase()).collect();
    |                                                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove closure as shown: `char::to_ascii_uppercase`