elided_named_lifetimes: add tests

Author: GrigorenkoPV

tests/ui/lint/elided-named-lifetimes/example-from-issue48686.rs

@@ -0,0 +1,12 @@
+#![deny(elided_named_lifetimes)]
+
+struct Foo;
+
+impl Foo {
+    pub fn get_mut(&'static self, x: &mut u8) -> &mut u8 {
+        //~^ ERROR elided lifetime has a name
+        unsafe { &mut *(x as *mut _) }
+    }
+}
+
+fn main() {}

tests/ui/lint/elided-named-lifetimes/example-from-issue48686.stderr

@@ -0,0 +1,14 @@
+error: elided lifetime has a name
+  --> $DIR/example-from-issue48686.rs:6:50
+   |
+LL |     pub fn get_mut(&'static self, x: &mut u8) -> &mut u8 {
+   |                                                  ^ this elided lifetime gets resolved as `'static`
+   |
+note: the lint level is defined here
+  --> $DIR/example-from-issue48686.rs:1:9
+   |
+LL | #![deny(elided_named_lifetimes)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+

tests/ui/lint/elided-named-lifetimes/missing-lifetime-kind.rs

@@ -0,0 +1,27 @@
+#![deny(elided_named_lifetimes)]
+
+fn ampersand<'a>(x: &'a u8) -> &u8 {
+    //~^ ERROR elided lifetime has a name
+    x
+}
+
+struct Brackets<'a>(&'a u8);
+
+fn brackets<'a>(x: &'a u8) -> Brackets {
+    //~^ ERROR elided lifetime has a name
+    Brackets(x)
+}
+
+struct Comma<'a, T>(&'a T);
+
+fn comma<'a>(x: &'a u8) -> Comma<u8> {
+    //~^ ERROR elided lifetime has a name
+    Comma(x)
+}
+
+fn underscore<'a>(x: &'a u8) -> &'_ u8 {
+    //~^ ERROR elided lifetime has a name
+    x
+}
+
+fn main() {}

tests/ui/lint/elided-named-lifetimes/missing-lifetime-kind.stderr

@@ -0,0 +1,40 @@
+error: elided lifetime has a name
+  --> $DIR/missing-lifetime-kind.rs:3:32
+   |
+LL | fn ampersand<'a>(x: &'a u8) -> &u8 {
+   |              --                ^ this elided lifetime gets resolved as `'a`
+   |              |
+   |              lifetime `'a` declared here
+   |
+note: the lint level is defined here
+  --> $DIR/missing-lifetime-kind.rs:1:9
+   |
+LL | #![deny(elided_named_lifetimes)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^
+
+error: elided lifetime has a name
+  --> $DIR/missing-lifetime-kind.rs:10:31
+   |
+LL | fn brackets<'a>(x: &'a u8) -> Brackets {
+   |             --                ^^^^^^^^ this elided lifetime gets resolved as `'a`
+   |             |
+   |             lifetime `'a` declared here
+
+error: elided lifetime has a name
+  --> $DIR/missing-lifetime-kind.rs:17:33
+   |
+LL | fn comma<'a>(x: &'a u8) -> Comma<u8> {
+   |          --                     ^ this elided lifetime gets resolved as `'a`
+   |          |
+   |          lifetime `'a` declared here
+
+error: elided lifetime has a name
+  --> $DIR/missing-lifetime-kind.rs:22:34
+   |
+LL | fn underscore<'a>(x: &'a u8) -> &'_ u8 {
+   |               --                 ^^ this elided lifetime gets resolved as `'a`
+   |               |
+   |               lifetime `'a` declared here
+
+error: aborting due to 4 previous errors
+

tests/ui/lint/elided-named-lifetimes/static.rs

@@ -0,0 +1,46 @@
+#![deny(elided_named_lifetimes)]
+
+use std::borrow::Cow;
+
+const A: &[u8] = &[];
+static B: &str = "hello";
+
+trait Trait {
+    const C: &u8 = &0;
+}
+
+impl Trait for () {
+    const C: &u8 = &1;
+}
+
+fn ampersand(x: &'static u8) -> &u8 {
+    //~^ ERROR elided lifetime has a name
+    x
+}
+
+struct Brackets<'a>(&'a u8);
+
+fn brackets(x: &'static u8) -> Brackets {
+    //~^ ERROR elided lifetime has a name
+    Brackets(x)
+}
+
+struct Comma<'a, T>(&'a T);
+
+fn comma(x: &'static u8) -> Comma<u8> {
+    //~^ ERROR elided lifetime has a name
+    Comma(x)
+}
+
+fn underscore(x: &'static u8) -> &'_ u8 {
+    //~^ ERROR elided lifetime has a name
+    x
+}
+
+const NESTED: &Vec<&Box<Cow<str>>> = &vec![];
+
+fn main() {
+    const HELLO: &str = "Hello";
+    static WORLD: &str = "world";
+    println!("{HELLO}, {WORLD}!")
+}

tests/ui/lint/elided-named-lifetimes/static.stderr

@@ -0,0 +1,32 @@
+error: elided lifetime has a name
+  --> $DIR/static.rs:16:33
+   |
+LL | fn ampersand(x: &'static u8) -> &u8 {
+   |                                 ^ this elided lifetime gets resolved as `'static`
+   |
+note: the lint level is defined here
+  --> $DIR/static.rs:1:9
+   |
+LL | #![deny(elided_named_lifetimes)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^
+
+error: elided lifetime has a name
+  --> $DIR/static.rs:23:32
+   |
+LL | fn brackets(x: &'static u8) -> Brackets {
+   |                                ^^^^^^^^ this elided lifetime gets resolved as `'static`
+
+error: elided lifetime has a name
+  --> $DIR/static.rs:30:34
+   |
+LL | fn comma(x: &'static u8) -> Comma<u8> {
+   |                                  ^ this elided lifetime gets resolved as `'static`
+
+error: elided lifetime has a name
+  --> $DIR/static.rs:35:35
+   |
+LL | fn underscore(x: &'static u8) -> &'_ u8 {
+   |                                   ^^ this elided lifetime gets resolved as `'static`
+
+error: aborting due to 4 previous errors
+