Don't complete ; when in closure return expression

Completing it will break syntax.

crates/ide-completion/src/render/function.rs

@@ -6,7 +6,7 @@ use hir::{db::HirDatabase, AsAssocItem, HirDisplay};
 use ide_db::{SnippetCap, SymbolKind};
 use itertools::Itertools;
 use stdx::{format_to, to_lower_snake_case};
-use syntax::{ast, format_smolstr, AstNode, Edition, SmolStr, SyntaxKind, ToSmolStr, T};
+use syntax::{ast, format_smolstr, match_ast, AstNode, Edition, SmolStr, SyntaxKind, ToSmolStr, T};
 
 use crate::{
     context::{CompletionContext, DotAccess, DotAccessKind, PathCompletionCtx, PathKind},
@@ -278,13 +278,25 @@ pub(super) fn add_call_parens<'b>(
         (snippet, "(…)")
     };
     if ret_type.is_unit() && ctx.config.add_semicolon_to_unit {
+        let inside_closure_ret = ctx.token.parent_ancestors().try_for_each(|ancestor| {
+            match_ast! {
+                match ancestor {
+                    ast::BlockExpr(_) => ControlFlow::Break(false),
+                    ast::ClosureExpr(_) => ControlFlow::Break(true),
+                    _ => ControlFlow::Continue(())
+                }
+            }
+        });
+
+        if inside_closure_ret != ControlFlow::Break(true) {
             let next_non_trivia_token =
                 std::iter::successors(ctx.token.next_token(), |it| it.next_token())
                     .find(|it| !it.kind().is_trivia());
             let in_match_arm = ctx.token.parent_ancestors().try_for_each(|ancestor| {
                 if ast::MatchArm::can_cast(ancestor.kind()) {
                     ControlFlow::Break(true)
-            } else if matches!(ancestor.kind(), SyntaxKind::EXPR_STMT | SyntaxKind::BLOCK_EXPR) {
+                } else if matches!(ancestor.kind(), SyntaxKind::EXPR_STMT | SyntaxKind::BLOCK_EXPR)
+                {
                     ControlFlow::Break(false)
                 } else {
                     ControlFlow::Continue(())
@@ -306,6 +318,7 @@ pub(super) fn add_call_parens<'b>(
                 }
             }
         }
+    }
     builder.label(SmolStr::from_iter([&name, label_suffix])).insert_snippet(cap, snippet)
 }
 
@@ -886,6 +899,27 @@ fn bar() {
         v => foo()$0,
     }
 }
+"#,
+        );
+    }
+
+    #[test]
+    fn no_semicolon_in_closure_ret() {
+        check_edit(
+            r#"foo"#,
+            r#"
+fn foo() {}
+fn baz(_: impl FnOnce()) {}
+fn bar() {
+    baz(|| fo$0);
+}
+"#,
+            r#"
+fn foo() {}
+fn baz(_: impl FnOnce()) {}
+fn bar() {
+    baz(|| foo()$0);
+}
 "#,
         );
     }