From fb90bf9cad41c971bc71b5fbbfe3df4eac70f0c1 Mon Sep 17 00:00:00 2001
From: rainy-me <github@yue.coffee>
Date: Sat, 4 Dec 2021 03:19:19 +0900
Subject: [PATCH] feat: handle while let to loop

---
 .../src/handlers/convert_while_to_loop.rs     | 63 ++++++++++---------
 1 file changed, 34 insertions(+), 29 deletions(-)

diff --git a/crates/ide_assists/src/handlers/convert_while_to_loop.rs b/crates/ide_assists/src/handlers/convert_while_to_loop.rs
index 92dc2ee73a3..a87d8d7166e 100644
--- a/crates/ide_assists/src/handlers/convert_while_to_loop.rs
+++ b/crates/ide_assists/src/handlers/convert_while_to_loop.rs
@@ -39,17 +39,14 @@
 // ```
 pub(crate) fn convert_while_to_loop(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     let while_kw = ctx.find_token_syntax_at_offset(T![while])?;
-    let while_expr: ast::WhileExpr = while_kw.parent().and_then(ast::WhileExpr::cast)?;
+    let while_expr = while_kw.parent().and_then(ast::WhileExpr::cast)?;
     let while_body = while_expr.loop_body()?;
-    let cond = while_expr.condition()?;
+    let while_cond = while_expr.condition()?;
 
-    // Don't handle while let
-    if cond.pat().is_some() {
-        return None;
+    let if_cond = match while_cond.pat() {
+        Some(_) => while_expr.condition()?,
+        None => make::condition(invert_boolean_expression(while_cond.expr()?), None),
     };
-
-    let cond_expr = cond.expr()?;
-
     let target = while_expr.syntax().text_range();
     acc.add(
         AssistId("convert_while_to_loop", AssistKind::RefactorRewrite),
@@ -58,27 +55,24 @@ pub(crate) fn convert_while_to_loop(acc: &mut Assists, ctx: &AssistContext) -> O
         |edit| {
             let while_indent_level = IndentLevel::from_node(while_expr.syntax());
 
-            let replacement = {
-                let if_expr = {
-                    let cond = invert_boolean_expression(cond_expr);
-                    let then_branch = make::block_expr(
-                        once(make::expr_stmt(make::expr_break(None)).into()),
-                        None,
-                    );
-
-                    make::expr_if(make::condition(cond, None), then_branch, None)
-                };
-
-                let if_expr = if_expr.indent(while_indent_level);
-                let stmts = once(make::expr_stmt(if_expr).into()).chain(while_body.statements());
-
-                let block_expr = make::block_expr(stmts, while_body.tail_expr());
-
-                let block_expr = block_expr.indent(while_indent_level);
-
-                make::expr_loop(block_expr)
+            let break_block =
+                make::block_expr(once(make::expr_stmt(make::expr_break(None)).into()), None)
+                    .indent(while_indent_level);
+            let block_expr = match while_cond.pat() {
+                Some(_) => {
+                    let if_expr = make::expr_if(if_cond, while_body, Some(break_block.into()));
+                    let stmts = once(make::expr_stmt(if_expr).into());
+                    make::block_expr(stmts, None)
+                }
+                None => {
+                    let if_expr = make::expr_if(if_cond, break_block, None);
+                    let stmts =
+                        once(make::expr_stmt(if_expr).into()).chain(while_body.statements());
+                    make::block_expr(stmts, while_body.tail_expr())
+                }
             };
 
+            let replacement = make::expr_loop(block_expr.indent(while_indent_level));
             edit.replace(target, replacement.syntax().text())
         },
     )
@@ -160,8 +154,8 @@ fn main() {
     }
 
     #[test]
-    fn ignore_while_let() {
-        check_assist_not_applicable(
+    fn convert_while_let() {
+        check_assist(
             convert_while_to_loop,
             r#"
 fn main() {
@@ -169,6 +163,17 @@ fn main() {
         bar();
     }
 }
+"#,
+            r#"
+fn main() {
+    loop {
+        if let Some(_) = foo() {
+            bar();
+        } else {
+            break;
+        }
+    }
+}
 "#,
         );
     }