add more tests for manual_repeat_n

Author: lapla-cogito

tests/ui/manual_repeat_n.fixed

@@ -14,15 +14,17 @@ fn main() {
     let _ = std::iter::repeat_n(vec![1, 2], 2);
 }
 
-mod external_lib {
+mod foo_lib {
     pub fn iter() -> std::iter::Take<std::iter::Repeat<&'static [u8]>> {
         todo!()
     }
 }
+
 fn foo() {
     let _ = match 1 {
-        1 => external_lib::iter(),
-        2 => std::iter::repeat_n([1, 2].as_slice(), 2), // can't really change this to repeat_n
+        1 => foo_lib::iter(),
+        // Shouldn't lint because `external_lib::iter` doesn't return `std::iter::RepeatN`.
+        2 => std::iter::repeat([1, 2].as_slice()).take(2),
         _ => todo!(),
     };
 }

tests/ui/manual_repeat_n.rs

@@ -23,8 +23,8 @@ mod foo_lib {
 fn foo() {
     let _ = match 1 {
         1 => foo_lib::iter(),
-        2 => std::iter::repeat([1, 2].as_slice()).take(2), /* Shouldn't lint because `external_lib::iter` doesn't */
-        // return `std::iter::RepeatN`.
+        // Shouldn't lint because `external_lib::iter` doesn't return `std::iter::RepeatN`.
+        2 => std::iter::repeat([1, 2].as_slice()).take(2),
         _ => todo!(),
     };
 }

tests/ui/manual_repeat_n.stderr

@@ -31,11 +31,5 @@ error: this `.repeat().take()` can be written more concisely
 LL |     let _ = repeat(vec![1, 2]).take(2);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `repeat_n()` instead: `std::iter::repeat_n(vec![1, 2], 2)`
 
-error: this `.repeat().take()` can be written more concisely
-  --> tests/ui/manual_repeat_n.rs:25:14
-   |
-LL |         2 => std::iter::repeat([1, 2].as_slice()).take(2), // can't really change this to repeat_n
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `repeat_n()` instead: `std::iter::repeat_n([1, 2].as_slice(), 2)`
-
-error: aborting due to 6 previous errors
+error: aborting due to 5 previous errors