Fix if_then_some_else_none FP when encountering await codes (rust-lang#16178)

changelog: Fix FP of [`if_then_some_else_none`] when the `then` block
contains `await` codes.

That is because `bool:then` doesn't work with await code.

Closes: rust-lang#16176

Author: Jarcho

clippy_lints/src/if_then_some_else_none.rs

@@ -4,10 +4,12 @@ use clippy_utils::eager_or_lazy::switch_to_eager_eval;
 use clippy_utils::msrvs::{self, Msrv};
 use clippy_utils::source::{snippet_with_applicability, snippet_with_context, walk_span_to_context};
 use clippy_utils::sugg::Sugg;
+use clippy_utils::visitors::for_each_expr_without_closures;
 use clippy_utils::{
-    as_some_expr, contains_return, expr_adjustment_requires_coercion, higher, is_else_clause, is_in_const_context,
-    is_none_expr, peel_blocks, sym,
+    as_some_expr, expr_adjustment_requires_coercion, higher, is_else_clause, is_in_const_context, is_none_expr,
+    peel_blocks, sym,
 };
+use core::ops::ControlFlow;
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
@@ -76,8 +78,14 @@ impl<'tcx> LateLintPass<'tcx> for IfThenSomeElseNone {
             && !is_else_clause(cx.tcx, expr)
             && !is_in_const_context(cx)
             && self.msrv.meets(cx, msrvs::BOOL_THEN)
-            && !contains_return(then_block.stmts)
-            && then_block.expr.is_none_or(|expr| !contains_return(expr))
+            && for_each_expr_without_closures(then_block, |e| {
+                if matches!(e.kind, ExprKind::Ret(..) | ExprKind::Yield(..)) {
+                    ControlFlow::Break(())
+                } else {
+                    ControlFlow::Continue(())
+                }
+            })
+            .is_none()
         {
             let method_name = if switch_to_eager_eval(cx, expr) && self.msrv.meets(cx, msrvs::BOOL_THEN_SOME) {
                 sym::then_some

tests/ui/if_then_some_else_none.fixed

@@ -218,3 +218,13 @@ mod issue15770 {
         Ok(())
     }
 }
+
+mod issue16176 {
+    pub async fn foo() -> u32 {
+        todo!()
+    }
+
+    pub async fn bar(cond: bool) -> Option<u32> {
+        if cond { Some(foo().await) } else { None } // OK
+    }
+}

tests/ui/if_then_some_else_none.rs

@@ -274,3 +274,13 @@ mod issue15770 {
         Ok(())
     }
 }
+
+mod issue16176 {
+    pub async fn foo() -> u32 {
+        todo!()
+    }
+
+    pub async fn bar(cond: bool) -> Option<u32> {
+        if cond { Some(foo().await) } else { None } // OK
+    }
+}