1 files changed, 65 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/map_flatten_fixable.fixed b/src/tools/clippy/tests/ui/map_flatten_fixable.fixed
new file mode 100644
index 000000000..312819a0a
--- /dev/null
+++ b/src/tools/clippy/tests/ui/map_flatten_fixable.fixed
@@ -0,0 +1,65 @@
+// run-rustfix
+
+#![warn(clippy::all, clippy::pedantic)]
+#![allow(clippy::let_underscore_drop)]
+#![allow(clippy::missing_docs_in_private_items)]
+#![allow(clippy::map_identity)]
+#![allow(clippy::redundant_closure)]
+#![allow(clippy::unnecessary_wraps)]
+#![feature(result_flattening)]
+
+fn main() {
+    // mapping to Option on Iterator
+    fn option_id(x: i8) -> Option<i8> {
+        Some(x)
+    }
+    let option_id_ref: fn(i8) -> Option<i8> = option_id;
+    let option_id_closure = |x| Some(x);
+    let _: Vec<_> = vec![5_i8; 6].into_iter().filter_map(option_id).collect();
+    let _: Vec<_> = vec![5_i8; 6].into_iter().filter_map(option_id_ref).collect();
+    let _: Vec<_> = vec![5_i8; 6].into_iter().filter_map(option_id_closure).collect();
+    let _: Vec<_> = vec![5_i8; 6].into_iter().filter_map(|x| x.checked_add(1)).collect();
+
+    // mapping to Iterator on Iterator
+    let _: Vec<_> = vec![5_i8; 6].into_iter().flat_map(|x| 0..x).collect();
+
+    // mapping to Option on Option
+    let _: Option<_> = (Some(Some(1))).and_then(|x| x);
+
+    // mapping to Result on Result
+    let _: Result<_, &str> = (Ok(Ok(1))).and_then(|x| x);
+
+    issue8734();
+    issue8878();
+}
+
+fn issue8734() {
+    let _ = [0u8, 1, 2, 3]
+        .into_iter()
+        .flat_map(|n| match n {
+            1 => [n
+                .saturating_add(1)
+                .saturating_add(1)
+                .saturating_add(1)
+                .saturating_add(1)
+                .saturating_add(1)
+                .saturating_add(1)
+                .saturating_add(1)
+                .saturating_add(1)],
+            n => [n],
+        });
+}
+
+#[allow(clippy::bind_instead_of_map)] // map + flatten will be suggested to `and_then`, but afterwards `map` is suggested again
+#[rustfmt::skip] // whitespace is important for this one
+fn issue8878() {
+    std::collections::HashMap::<u32, u32>::new()
+        .get(&0)
+        .and_then(|_| {
+// we need some newlines
+// so that the span is big enough
+// for a split output of the diagnostic
+            Some("")
+ // whitespace beforehand is important as well
+        });
+}