fix(ide-assists): unwrap block when it parent is let stmt

crates/ide-assists/src/handlers/unwrap_block.rs

@@ -2,6 +2,7 @@
     ast::{
         self,
         edit::{AstNodeEdit, IndentLevel},
+        make,
     },
     AstNode, SyntaxKind, TextRange, T,
 };
@@ -37,15 +38,42 @@ pub(crate) fn unwrap_block(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option
         parent = parent.ancestors().find(|it| ast::MatchExpr::can_cast(it.kind()))?
     }
 
-    if matches!(parent.kind(), SyntaxKind::STMT_LIST | SyntaxKind::EXPR_STMT | SyntaxKind::LET_STMT)
+    let kind = parent.kind();
-    {
+    if matches!(kind, SyntaxKind::STMT_LIST | SyntaxKind::EXPR_STMT) {
-        return acc.add(assist_id, assist_label, target, |builder| {
+        acc.add(assist_id, assist_label, target, |builder| {
             builder.replace(block.syntax().text_range(), update_expr_string(block.to_string()));
-        });
+        })
+    } else if matches!(kind, SyntaxKind::LET_STMT) {
+        let parent = ast::LetStmt::cast(parent)?;
+        let pattern = ast::Pat::cast(parent.syntax().first_child()?)?;
+        let ty = parent.ty();
+        let list = block.stmt_list()?;
+        let replaced = match list.syntax().last_child() {
+            Some(last) => {
+                let stmts: Vec<ast::Stmt> = list.statements().collect();
+                let initializer = ast::Expr::cast(last.clone())?;
+                let let_stmt = make::let_stmt(pattern, ty, Some(initializer));
+                if stmts.len() > 0 {
+                    let block = make::block_expr(stmts, None);
+                    format!(
+                        "{}\n    {}",
+                        update_expr_string(block.to_string()),
+                        let_stmt.to_string()
+                    )
+                } else {
+                    let_stmt.to_string()
                 }
-
+            }
+            None => {
+                let empty_tuple = make::expr_tuple([]);
+                make::let_stmt(pattern, ty, Some(empty_tuple)).to_string()
+            }
+        };
+        acc.add(assist_id, assist_label, target, |builder| {
+            builder.replace(parent.syntax().text_range(), replaced);
+        })
+    } else {
         let parent = ast::Expr::cast(parent)?;
-
         match parent.clone() {
             ast::Expr::ForExpr(_) | ast::Expr::WhileExpr(_) | ast::Expr::LoopExpr(_) => (),
             ast::Expr::MatchExpr(_) => block = block.dedent(IndentLevel(1)),
@@ -93,6 +121,7 @@ pub(crate) fn unwrap_block(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option
             builder.replace(parent.syntax().text_range(), update_expr_string(block.to_string()));
         })
     }
+}
 
 fn update_expr_string(expr_string: String) -> String {
     update_expr_string_with_pat(expr_string, &[' ', '\n'])
@@ -724,6 +753,19 @@ fn unwrap_block_in_let_initializers() {
         check_assist(
             unwrap_block,
             r#"
+fn main() {
+    let x = {$0};
+}
+"#,
+            r#"
+fn main() {
+    let x = ();
+}
+"#,
+        );
+        check_assist(
+            unwrap_block,
+            r#"
 fn main() {
     let x = {$0
         bar
@@ -734,6 +776,34 @@ fn main() {
 fn main() {
     let x = bar;
 }
+"#,
+        );
+        check_assist(
+            unwrap_block,
+            r#"
+fn main() -> i32 {
+    let _ = {$01; 2};
+}
+"#,
+            r#"
+fn main() -> i32 {
+    1;
+    let _ = 2;
+}
+"#,
+        );
+        check_assist(
+            unwrap_block,
+            r#"
+fn main() -> i32 {
+    let mut a = {$01; 2};
+}
+"#,
+            r#"
+fn main() -> i32 {
+    1;
+    let mut a = 2;
+}
 "#,
         );
     }