fix assists

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 {

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),
     }
 }

crates/ra_ide_api/src/syntax_tree.rs

@@ -116,6 +116,7 @@ SOURCE_FILE@[0; 11)
       L_PAREN@[6; 7) "("
       R_PAREN@[7; 8) ")"
     WHITESPACE@[8; 9) " "
+    BLOCK_EXPR@[9; 11)
       BLOCK@[9; 11)
         L_CURLY@[9; 10) "{"
         R_CURLY@[10; 11) "}"
@@ -148,6 +149,7 @@ SOURCE_FILE@[0; 60)
       L_PAREN@[7; 8) "("
       R_PAREN@[8; 9) ")"
     WHITESPACE@[9; 10) " "
+    BLOCK_EXPR@[10; 60)
       BLOCK@[10; 60)
         L_CURLY@[10; 11) "{"
         WHITESPACE@[11; 16) "\n    "
@@ -190,6 +192,7 @@ FN_DEF@[0; 11)
     L_PAREN@[6; 7) "("
     R_PAREN@[7; 8) ")"
   WHITESPACE@[8; 9) " "
+  BLOCK_EXPR@[9; 11)
     BLOCK@[9; 11)
       L_CURLY@[9; 10) "{"
       R_CURLY@[10; 11) "}"
@@ -258,6 +261,7 @@ SOURCE_FILE@[0; 12)
       L_PAREN@[6; 7) "("
       R_PAREN@[7; 8) ")"
     WHITESPACE@[8; 9) " "
+    BLOCK_EXPR@[9; 12)
       BLOCK@[9; 12)
         L_CURLY@[9; 10) "{"
         WHITESPACE@[10; 11) "\n"
@@ -292,6 +296,7 @@ SOURCE_FILE@[0; 12)
       L_PAREN@[6; 7) "("
       R_PAREN@[7; 8) ")"
     WHITESPACE@[8; 9) " "
+    BLOCK_EXPR@[9; 12)
       BLOCK@[9; 12)
         L_CURLY@[9; 10) "{"
         WHITESPACE@[10; 11) "\n"
@@ -325,6 +330,7 @@ SOURCE_FILE@[0; 25)
       L_PAREN@[6; 7) "("
       R_PAREN@[7; 8) ")"
     WHITESPACE@[8; 9) " "
+    BLOCK_EXPR@[9; 12)
       BLOCK@[9; 12)
         L_CURLY@[9; 10) "{"
         WHITESPACE@[10; 11) "\n"
@@ -339,6 +345,7 @@ SOURCE_FILE@[0; 25)
       L_PAREN@[19; 20) "("
       R_PAREN@[20; 21) ")"
     WHITESPACE@[21; 22) " "
+    BLOCK_EXPR@[22; 25)
       BLOCK@[22; 25)
         L_CURLY@[22; 23) "{"
         WHITESPACE@[23; 24) "\n"

crates/ra_mbe/src/tests.rs

@@ -678,6 +678,7 @@ fn test_expr_order() {
     PARAM_LIST@[5; 7)
       L_PAREN@[5; 6) "("
       R_PAREN@[6; 7) ")"
+    BLOCK_EXPR@[7; 15)
       BLOCK@[7; 15)
         L_CURLY@[7; 8) "{"
         EXPR_STMT@[8; 14)

crates/ra_syntax/src/ast/expr_extensions.rs

@@ -289,6 +289,26 @@ impl ast::Literal {
     }
 }
 
+impl ast::BlockExpr {
+    /// false if the block is an intrinsic part of the syntax and can't be
+    /// replaced with arbitrary expression.
+    ///
+    /// ```not_rust
+    /// fn foo() { not_stand_alone }
+    /// const FOO: () = { stand_alone };
+    /// ```
+    pub fn is_standalone(&self) -> bool {
+        let kind = match self.syntax().parent() {
+            None => return true,
+            Some(it) => it.kind(),
+        };
+        match kind {
+            FN_DEF | MATCH_ARM | IF_EXPR | WHILE_EXPR | LOOP_EXPR | TRY_BLOCK_EXPR => false,
+            _ => true,
+        }
+    }
+}
+
 #[test]
 fn test_literal_with_attr() {
     let parse = ast::SourceFile::parse(r#"const _: &str = { #[attr] "Hello" };"#);