Add new test for result_map_or_into_option extension

Author: GuillaumeGomez

tests/ui/result_map_or_into_option.fixed

@@ -1,8 +1,14 @@
-#![warn(clippy::result_map_or_into_option)]
+#![deny(clippy::result_map_or_into_option)]
 
 fn main() {
     let opt: Result<u32, &str> = Ok(1);
     let _ = opt.ok();
+    //~^ ERROR: called `map_or(None, Some)` on a `Result` value.
+    let _ = opt.ok();
+    //~^ ERROR: called `map_or_else(|_| None, Some)` on a `Result` value
+    #[rustfmt::skip]
+    let _ = opt.ok();
+    //~^ ERROR: called `map_or_else(|_| None, Some)` on a `Result` value
 
     let rewrap = |s: u32| -> Option<u32> { Some(s) };
 
@@ -14,4 +20,5 @@ fn main() {
     // return should not emit the lint
     let opt: Result<u32, &str> = Ok(1);
     _ = opt.map_or(None, |_x| Some(1));
+    let _ = opt.map_or_else(|a| a.parse::<u32>().ok(), Some);
 }

tests/ui/result_map_or_into_option.rs

@@ -1,8 +1,14 @@
-#![warn(clippy::result_map_or_into_option)]
+#![deny(clippy::result_map_or_into_option)]
 
 fn main() {
     let opt: Result<u32, &str> = Ok(1);
     let _ = opt.map_or(None, Some);
+    //~^ ERROR: called `map_or(None, Some)` on a `Result` value.
+    let _ = opt.map_or_else(|_| None, Some);
+    //~^ ERROR: called `map_or_else(|_| None, Some)` on a `Result` value
+    #[rustfmt::skip]
+    let _ = opt.map_or_else(|_| { None }, Some);
+    //~^ ERROR: called `map_or_else(|_| None, Some)` on a `Result` value
 
     let rewrap = |s: u32| -> Option<u32> { Some(s) };
 
@@ -14,4 +20,5 @@ fn main() {
     // return should not emit the lint
     let opt: Result<u32, &str> = Ok(1);
     _ = opt.map_or(None, |_x| Some(1));
+    let _ = opt.map_or_else(|a| a.parse::<u32>().ok(), Some);
 }

tests/ui/result_map_or_into_option.stderr

@@ -4,8 +4,23 @@ error: called `map_or(None, Some)` on a `Result` value. This can be done more di
 LL |     let _ = opt.map_or(None, Some);
    |             ^^^^^^^^^^^^^^^^^^^^^^ help: try using `ok` instead: `opt.ok()`
    |
-   = note: `-D clippy::result-map-or-into-option` implied by `-D warnings`
-   = help: to override `-D warnings` add `#[allow(clippy::result_map_or_into_option)]`
+note: the lint level is defined here
+  --> $DIR/result_map_or_into_option.rs:1:9
+   |
+LL | #![deny(clippy::result_map_or_into_option)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: called `map_or_else(|_| None, Some)` on a `Result` value
+  --> $DIR/result_map_or_into_option.rs:7:13
+   |
+LL |     let _ = opt.map_or_else(|_| None, Some);
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try using `ok` instead: `opt.ok()`
+
+error: called `map_or_else(|_| None, Some)` on a `Result` value
+  --> $DIR/result_map_or_into_option.rs:10:13
+   |
+LL |     let _ = opt.map_or_else(|_| { None }, Some);
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try using `ok` instead: `opt.ok()`
 
-error: aborting due to previous error
+error: aborting due to 3 previous errors