1 files changed, 100 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/map_flatten.stderr b/src/tools/clippy/tests/ui/map_flatten.stderr
new file mode 100644
index 000000000..4b2630d68
--- /dev/null
+++ b/src/tools/clippy/tests/ui/map_flatten.stderr
@@ -0,0 +1,100 @@
+error: called `map(..).flatten()` on `Option`
+  --> $DIR/map_flatten.rs:8:10
+   |
+LL |           .map(|x| {
+   |  __________^
+LL | |             if x <= 5 {
+LL | |                 Some(x)
+LL | |             } else {
+...  |
+LL | |         })
+LL | |         .flatten();
+   | |__________________^
+   |
+   = note: `-D clippy::map-flatten` implied by `-D warnings`
+help: try replacing `map` with `and_then` and remove the `.flatten()`
+   |
+LL ~         .and_then(|x| {
+LL +             if x <= 5 {
+LL +                 Some(x)
+LL +             } else {
+LL +                 None
+LL +             }
+LL ~         });
+   |
+
+error: called `map(..).flatten()` on `Result`
+  --> $DIR/map_flatten.rs:18:10
+   |
+LL |           .map(|x| {
+   |  __________^
+LL | |             if x == 1 {
+LL | |                 Ok(x)
+LL | |             } else {
+...  |
+LL | |         })
+LL | |         .flatten();
+   | |__________________^
+   |
+help: try replacing `map` with `and_then` and remove the `.flatten()`
+   |
+LL ~         .and_then(|x| {
+LL +             if x == 1 {
+LL +                 Ok(x)
+LL +             } else {
+LL +                 Err(0)
+LL +             }
+LL ~         });
+   |
+
+error: called `map(..).flatten()` on `Result`
+  --> $DIR/map_flatten.rs:30:10
+   |
+LL |           .map(|res| {
+   |  __________^
+LL | |             if res > 0 {
+LL | |                 do_something();
+LL | |                 Ok(res)
+...  |
+LL | |         })
+LL | |         .flatten();
+   | |__________________^
+   |
+help: try replacing `map` with `and_then` and remove the `.flatten()`
+   |
+LL ~         .and_then(|res| {
+LL +             if res > 0 {
+LL +                 do_something();
+LL +                 Ok(res)
+LL +             } else {
+LL +                 Err(0)
+LL +             }
+LL ~         });
+   |
+
+error: called `map(..).flatten()` on `Iterator`
+  --> $DIR/map_flatten.rs:42:10
+   |
+LL |           .map(|some_value| {
+   |  __________^
+LL | |             if some_value > 3 {
+LL | |                 Some(some_value)
+LL | |             } else {
+...  |
+LL | |         })
+LL | |         .flatten()
+   | |__________________^
+   |
+help: try replacing `map` with `filter_map` and remove the `.flatten()`
+   |
+LL ~         .filter_map(|some_value| {
+LL +             if some_value > 3 {
+LL +                 Some(some_value)
+LL +             } else {
+LL +                 None
+LL +             }
+LL +         })
+   |
+
+error: aborting due to 4 previous errors
+