2 files changed, 43 insertions, 69 deletions

diff --git a/crates/ide_diagnostics/src/handlers/replace_filter_map_next_with_find_map.rs b/crates/ide_diagnostics/src/handlers/replace_filter_map_next_with_find_map.rs
index cd87a10bb..839ceac03 100644
--- a/crates/ide_diagnostics/src/handlers/replace_filter_map_next_with_find_map.rs
+++ b/crates/ide_diagnostics/src/handlers/replace_filter_map_next_with_find_map.rs
@@ -55,44 +55,16 @@ fn fixes(
 
 #[cfg(test)]
 mod tests {
-    use crate::tests::check_fix;
-
-    // Register the required standard library types to make the tests work
-    #[track_caller]
-    fn check_diagnostics(ra_fixture: &str) {
-        let prefix = r#"
-//- /main.rs crate:main deps:core
-use core::iter::Iterator;
-use core::option::Option::{self, Some, None};
-"#;
-        let suffix = r#"
-//- /core/lib.rs crate:core
-pub mod option {
-    pub enum Option<T> { Some(T), None }
-}
-pub mod iter {
-    pub trait Iterator {
-        type Item;
-        fn filter_map<B, F>(self, f: F) -> FilterMap where F: FnMut(Self::Item) -> Option<B> { FilterMap }
-        fn next(&mut self) -> Option<Self::Item>;
-    }
-    pub struct FilterMap {}
-    impl Iterator for FilterMap {
-        type Item = i32;
-        fn next(&mut self) -> i32 { 7 }
-    }
-}
-"#;
-        crate::tests::check_diagnostics(&format!("{}{}{}", prefix, ra_fixture, suffix))
-    }
+    use crate::tests::{check_diagnostics, check_fix};
 
     #[test]
     fn replace_filter_map_next_with_find_map2() {
         check_diagnostics(
             r#"
-    fn foo() {
-        let m = [1, 2, 3].iter().filter_map(|x| Some(92)).next();
-    }         //^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 💡 weak: replace filter_map(..).next() with find_map(..)
+//- minicore: iterators
+fn foo() {
+    let m = core::iter::repeat(()).filter_map(|()| Some(92)).next();
+}         //^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 💡 weak: replace filter_map(..).next() with find_map(..)
 "#,
         );
     }
@@ -101,11 +73,11 @@ pub mod iter {
     fn replace_filter_map_next_with_find_map_no_diagnostic_without_next() {
         check_diagnostics(
             r#"
+//- minicore: iterators
 fn foo() {
-    let m = [1, 2, 3]
-        .iter()
-        .filter_map(|x| Some(92))
-        .len();
+    let m = core::iter::repeat(())
+        .filter_map(|()| Some(92))
+        .count();
 }
 "#,
         );
@@ -115,12 +87,12 @@ fn foo() {
     fn replace_filter_map_next_with_find_map_no_diagnostic_with_intervening_methods() {
         check_diagnostics(
             r#"
+//- minicore: iterators
 fn foo() {
-    let m = [1, 2, 3]
-        .iter()
-        .filter_map(|x| Some(92))
+    let m = core::iter::repeat(())
+        .filter_map(|()| Some(92))
         .map(|x| x + 2)
-        .len();
+        .next();
 }
 "#,
         );
@@ -130,10 +102,10 @@ fn foo() {
     fn replace_filter_map_next_with_find_map_no_diagnostic_if_not_in_chain() {
         check_diagnostics(
             r#"
+//- minicore: iterators
 fn foo() {
-    let m = [1, 2, 3]
-        .iter()
-        .filter_map(|x| Some(92));
+    let m = core::iter::repeat(())
+        .filter_map(|()| Some(92));
     let n = m.next();
 }
 "#,
@@ -144,34 +116,14 @@ fn foo() {
     fn replace_with_wind_map() {
         check_fix(
             r#"
-//- /main.rs crate:main deps:core
-use core::iter::Iterator;
-use core::option::Option::{self, Some, None};
+//- minicore: iterators
 fn foo() {
-    let m = [1, 2, 3].iter().$0filter_map(|x| Some(92)).next();
-}
-//- /core/lib.rs crate:core
-pub mod option {
-    pub enum Option<T> { Some(T), None }
-}
-pub mod iter {
-    pub trait Iterator {
-        type Item;
-        fn filter_map<B, F>(self, f: F) -> FilterMap where F: FnMut(Self::Item) -> Option<B> { FilterMap }
-        fn next(&mut self) -> Option<Self::Item>;
-    }
-    pub struct FilterMap {}
-    impl Iterator for FilterMap {
-        type Item = i32;
-        fn next(&mut self) -> i32 { 7 }
-    }
+    let m = core::iter::repeat(()).$0filter_map(|()| Some(92)).next();
 }
 "#,
             r#"
-use core::iter::Iterator;
-use core::option::Option::{self, Some, None};
 fn foo() {
-    let m = [1, 2, 3].iter().find_map(|x| Some(92));
+    let m = core::iter::repeat(()).find_map(|()| Some(92));
 }
 "#,
         )
diff --git a/crates/test_utils/src/minicore.rs b/crates/test_utils/src/minicore.rs
index 71f07d38a..ce6ad8541 100644
--- a/crates/test_utils/src/minicore.rs
+++ b/crates/test_utils/src/minicore.rs
@@ -22,7 +22,7 @@
 //!     option:
 //!     result:
 //!     iterator: option
-//!     iterators: iterator
+//!     iterators: iterator, fn
 //!     default: sized
 //!     clone: sized
 //!     copy: clone
@@ -390,7 +390,6 @@ pub mod iter {
             iter: I,
             n: usize,
         }
-
         impl<I> Iterator for Take<I>
         where
             I: Iterator,
@@ -401,6 +400,22 @@ pub mod iter {
                 loop {}
             }
         }
+
+        pub struct FilterMap<I, F> {
+            iter: I,
+            f: F,
+        }
+        impl<B, I: Iterator, F> Iterator for FilterMap<I, F>
+        where
+            F: FnMut(I::Item) -> Option<B>,
+        {
+            type Item = B;
+
+            #[inline]
+            fn next(&mut self) -> Option<B> {
+                loop {}
+            }
+        }
     }
     pub use self::adapters::Take;
 
@@ -448,6 +463,13 @@ pub mod iter {
                 fn take(self, n: usize) -> crate::iter::Take<Self> {
                     loop {}
                 }
+                fn filter_map<B, F>(self, f: F) -> crate::iter::FilterMap<Self, F>
+                where
+                    Self: Sized,
+                    F: FnMut(Self::Item) -> Option<B>,
+                {
+                    loop {}
+                }
                 // endregion:iterators
             }
             impl<I: Iterator + ?Sized> Iterator for &mut I {