add and test another edge case (explicit return)

Author: lolbinarycat

clippy_lints/src/and_then_then_some.rs

@@ -85,6 +85,10 @@ fn peel_closure_body<'tcx>(
     closure_arg_id: HirId,
 ) -> Option<&'tcx Expr<'tcx>> {
     match expr.kind {
+		ExprKind::Ret(Some(wrapped_expr)) =>
+		// duplicated blocks because 2023 reference statements are awkward.
+		// "&" peels multiple layers of indirection instead of just one like we want.
+			peel_closure_body(cx, wrapped_expr, closure_arg_id),
         // it would be nice if we could lift { x; y.a() } into { x; y }.a()
         ExprKind::Block(
             Block {
@@ -136,7 +140,9 @@ fn is_local_defined_at(cx: &LateContext<'_>, local: &Expr<'_>, arg_hid: HirId) -
 fn show_sugg(cx: &LateContext<'_>, span: Span, selfarg: &Expr<'_>, closure_args: Span, predicate: &Expr<'_>) {
     let mut appl = Applicability::MachineApplicable;
 	// FIXME: this relies on deref coertion, which won't work correctly if the predicate involves something
-	// other than a method call.
+	// other than a method call.  this is because `and_then` takes an argument by
+	// value, while `filter` takes an argument by reference.
+	
     let sugg = format!(
         "{}.filter(|{}| {})",
         snippet_with_applicability(cx, selfarg.span, "<OPTION>", &mut appl),

tests/ui/and_then_then_some.fixed

@@ -6,5 +6,7 @@ fn main() {
     let _y = x.clone().filter(|v| v.starts_with('f'));
 
     let _z = x.clone().filter(|v| v.starts_with('f'));
-    let _w = x.filter(|v| v.starts_with('f'));
+    let _w = x.clone().filter(|v| v.starts_with('f'));
+	#[allow(clippy::needless_return)]
+	let _v = x.clone().filter(|v| v.starts_with('g'));
 }

tests/ui/and_then_then_some.rs

@@ -6,5 +6,7 @@ fn main() {
     let _y = x.clone().and_then(|v| v.starts_with('f').then_some(v));
 
     let _z = x.clone().and_then(|v| bool::then_some(v.starts_with('f'), v));
-    let _w = Option::and_then(x, |v: String| bool::then_some(v.starts_with('f'), v));
+    let _w = Option::and_then(x.clone(), |v: String| bool::then_some(v.starts_with('f'), v));
+	#[allow(clippy::needless_return)]
+	let _v = x.clone().and_then(|v| return v.starts_with('g').then_some(v));
 }

tests/ui/and_then_then_some.stderr

@@ -16,8 +16,14 @@ LL |     let _z = x.clone().and_then(|v| bool::then_some(v.starts_with('f'), v))
 error: use of `Option::and_then` and `bool::then_some` is equivelent to `filter`
   --> tests/ui/and_then_then_some.rs:9:14
    |
-LL |     let _w = Option::and_then(x, |v: String| bool::then_some(v.starts_with('f'), v));
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `Option::filter` instead: `x.filter(|v| v.starts_with('f'))`
+LL |     let _w = Option::and_then(x.clone(), |v: String| bool::then_some(v.starts_with('f'), v));
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `Option::filter` instead: `x.clone().filter(|v| v.starts_with('f'))`
 
-error: aborting due to 3 previous errors
+error: use of `Option::and_then` and `bool::then_some` is equivelent to `filter`
+  --> tests/ui/and_then_then_some.rs:11:11
+   |
+LL |     let _v = x.clone().and_then(|v| return v.starts_with('g').then_some(v));
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `Option::filter` instead: `x.clone().filter(|v| v.starts_with('g'))`
+
+error: aborting due to 4 previous errors