4 files changed, 20 insertions, 11 deletions

diff --git a/crates/ra_assists/src/ast_editor.rs b/crates/ra_assists/src/ast_editor.rs
index 6815638dc..048478662 100644
--- a/crates/ra_assists/src/ast_editor.rs
+++ b/crates/ra_assists/src/ast_editor.rs
@@ -274,7 +274,7 @@ impl AstBuilder<ast::Block> {
 
 impl AstBuilder<ast::Expr> {
     fn from_text(text: &str) -> ast::Expr {
-        ast_node_from_file_text(&format!("fn f() {{ {}; }}", text))
+        ast_node_from_file_text(&format!("const C: () = {};", text))
     }
 
     pub fn unit() -> ast::Expr {
diff --git a/crates/ra_assists/src/introduce_variable.rs b/crates/ra_assists/src/introduce_variable.rs
index 95c18d0e3..470ffe120 100644
--- a/crates/ra_assists/src/introduce_variable.rs
+++ b/crates/ra_assists/src/introduce_variable.rs
@@ -3,7 +3,8 @@ use hir::db::HirDatabase;
 use ra_syntax::{
     ast::{self, AstNode},
     SyntaxKind::{
-        BREAK_EXPR, COMMENT, LAMBDA_EXPR, LOOP_EXPR, MATCH_ARM, PATH_EXPR, RETURN_EXPR, WHITESPACE,
+        BLOCK_EXPR, BREAK_EXPR, COMMENT, LAMBDA_EXPR, LOOP_EXPR, MATCH_ARM, PATH_EXPR, RETURN_EXPR,
+        WHITESPACE,
     },
     SyntaxNode, TextUnit,
 };
@@ -80,10 +81,12 @@ pub(crate) fn introduce_variable(mut ctx: AssistCtx<impl HirDatabase>) -> Option
 /// In general that's true for any expression, but in some cases that would produce invalid code.
 fn valid_target_expr(node: SyntaxNode) -> Option<ast::Expr> {
     match node.kind() {
-        PATH_EXPR => None,
+        PATH_EXPR | LOOP_EXPR => None,
         BREAK_EXPR => ast::BreakExpr::cast(node).and_then(|e| e.expr()),
         RETURN_EXPR => ast::ReturnExpr::cast(node).and_then(|e| e.expr()),
-        LOOP_EXPR => ast::ReturnExpr::cast(node).and_then(|e| e.expr()),
+        BLOCK_EXPR => {
+            ast::BlockExpr::cast(node).filter(|it| it.is_standalone()).map(ast::Expr::from)
+        }
         _ => ast::Expr::cast(node),
     }
 }
diff --git a/crates/ra_assists/src/move_guard.rs b/crates/ra_assists/src/move_guard.rs
index 127c9e068..699221e33 100644
--- a/crates/ra_assists/src/move_guard.rs
+++ b/crates/ra_assists/src/move_guard.rs
@@ -65,9 +65,9 @@ pub(crate) fn move_arm_cond_to_match_guard(mut ctx: AssistCtx<impl HirDatabase>)
         "move condition to match guard",
         |edit| {
             edit.target(if_expr.syntax().text_range());
-            let then_only_expr = then_block.statements().next().is_none();
+            let then_only_expr = then_block.block().and_then(|it| it.statements().next()).is_none();
 
-            match &then_block.expr() {
+            match &then_block.block().and_then(|it| it.expr()) {
                 Some(then_expr) if then_only_expr => {
                     edit.replace(if_expr.syntax().text_range(), then_expr.syntax().text())
                 }
diff --git a/crates/ra_assists/src/replace_if_let_with_match.rs b/crates/ra_assists/src/replace_if_let_with_match.rs
index c0bf6d235..401835c57 100644
--- a/crates/ra_assists/src/replace_if_let_with_match.rs
+++ b/crates/ra_assists/src/replace_if_let_with_match.rs
@@ -1,3 +1,4 @@
+use format_buf::format;
 use hir::db::HirDatabase;
 use ra_fmt::extract_trivial_expression;
 use ra_syntax::{ast, AstNode};
@@ -25,16 +26,21 @@ pub(crate) fn replace_if_let_with_match(mut ctx: AssistCtx<impl HirDatabase>) ->
     ctx.build()
 }
 
-fn build_match_expr(expr: ast::Expr, pat1: ast::Pat, arm1: ast::Block, arm2: ast::Block) -> String {
+fn build_match_expr(
+    expr: ast::Expr,
+    pat1: ast::Pat,
+    arm1: ast::BlockExpr,
+    arm2: ast::BlockExpr,
+) -> String {
     let mut buf = String::new();
-    buf.push_str(&format!("match {} {{\n", expr.syntax().text()));
-    buf.push_str(&format!("    {} => {}\n", pat1.syntax().text(), format_arm(&arm1)));
-    buf.push_str(&format!("    _ => {}\n", format_arm(&arm2)));
+    format!(buf, "match {} {{\n", expr.syntax().text());
+    format!(buf, "    {} => {}\n", pat1.syntax().text(), format_arm(&arm1));
+    format!(buf, "    _ => {}\n", format_arm(&arm2));
     buf.push_str("}");
     buf
 }
 
-fn format_arm(block: &ast::Block) -> String {
+fn format_arm(block: &ast::BlockExpr) -> String {
     match extract_trivial_expression(block) {
         None => block.syntax().text().to_string(),
         Some(e) => format!("{},", e.syntax().text()),