fix assists

5 files changed, 92 insertions, 61 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_ide_api/src/syntax_tree.rs b/crates/ra_ide_api/src/syntax_tree.rs
index dd31b9093..914759709 100644
--- a/crates/ra_ide_api/src/syntax_tree.rs
+++ b/crates/ra_ide_api/src/syntax_tree.rs
@@ -116,9 +116,10 @@ SOURCE_FILE@[0; 11)
       L_PAREN@[6; 7) "("

       R_PAREN@[7; 8) ")"

     WHITESPACE@[8; 9) " "

-    BLOCK@[9; 11)

-      L_CURLY@[9; 10) "{"

-      R_CURLY@[10; 11) "}"

+    BLOCK_EXPR@[9; 11)

+      BLOCK@[9; 11)

+        L_CURLY@[9; 10) "{"

+        R_CURLY@[10; 11) "}"

 "#

             .trim()

         );

@@ -148,26 +149,27 @@ SOURCE_FILE@[0; 60)
       L_PAREN@[7; 8) "("

       R_PAREN@[8; 9) ")"

     WHITESPACE@[9; 10) " "

-    BLOCK@[10; 60)

-      L_CURLY@[10; 11) "{"

-      WHITESPACE@[11; 16) "\n    "

-      EXPR_STMT@[16; 58)

-        MACRO_CALL@[16; 57)

-          PATH@[16; 22)

-            PATH_SEGMENT@[16; 22)

-              NAME_REF@[16; 22)

-                IDENT@[16; 22) "assert"

-          EXCL@[22; 23) "!"

-          TOKEN_TREE@[23; 57)

-            L_PAREN@[23; 24) "("

-            STRING@[24; 52) "\"\n    fn foo() {\n     ..."

-            COMMA@[52; 53) ","

-            WHITESPACE@[53; 54) " "

-            STRING@[54; 56) "\"\""

-            R_PAREN@[56; 57) ")"

-        SEMI@[57; 58) ";"

-      WHITESPACE@[58; 59) "\n"

-      R_CURLY@[59; 60) "}"

+    BLOCK_EXPR@[10; 60)

+      BLOCK@[10; 60)

+        L_CURLY@[10; 11) "{"

+        WHITESPACE@[11; 16) "\n    "

+        EXPR_STMT@[16; 58)

+          MACRO_CALL@[16; 57)

+            PATH@[16; 22)

+              PATH_SEGMENT@[16; 22)

+                NAME_REF@[16; 22)

+                  IDENT@[16; 22) "assert"

+            EXCL@[22; 23) "!"

+            TOKEN_TREE@[23; 57)

+              L_PAREN@[23; 24) "("

+              STRING@[24; 52) "\"\n    fn foo() {\n     ..."

+              COMMA@[52; 53) ","

+              WHITESPACE@[53; 54) " "

+              STRING@[54; 56) "\"\""

+              R_PAREN@[56; 57) ")"

+          SEMI@[57; 58) ";"

+        WHITESPACE@[58; 59) "\n"

+        R_CURLY@[59; 60) "}"

 "#

             .trim()

         );

@@ -190,9 +192,10 @@ FN_DEF@[0; 11)
     L_PAREN@[6; 7) "("

     R_PAREN@[7; 8) ")"

   WHITESPACE@[8; 9) " "

-  BLOCK@[9; 11)

-    L_CURLY@[9; 10) "{"

-    R_CURLY@[10; 11) "}"

+  BLOCK_EXPR@[9; 11)

+    BLOCK@[9; 11)

+      L_CURLY@[9; 10) "{"

+      R_CURLY@[10; 11) "}"

 "#

             .trim()

         );

@@ -258,10 +261,11 @@ SOURCE_FILE@[0; 12)
       L_PAREN@[6; 7) "("

       R_PAREN@[7; 8) ")"

     WHITESPACE@[8; 9) " "

-    BLOCK@[9; 12)

-      L_CURLY@[9; 10) "{"

-      WHITESPACE@[10; 11) "\n"

-      R_CURLY@[11; 12) "}"

+    BLOCK_EXPR@[9; 12)

+      BLOCK@[9; 12)

+        L_CURLY@[9; 10) "{"

+        WHITESPACE@[10; 11) "\n"

+        R_CURLY@[11; 12) "}"

 "#

             .trim()

         );

@@ -292,10 +296,11 @@ SOURCE_FILE@[0; 12)
       L_PAREN@[6; 7) "("

       R_PAREN@[7; 8) ")"

     WHITESPACE@[8; 9) " "

-    BLOCK@[9; 12)

-      L_CURLY@[9; 10) "{"

-      WHITESPACE@[10; 11) "\n"

-      R_CURLY@[11; 12) "}"

+    BLOCK_EXPR@[9; 12)

+      BLOCK@[9; 12)

+        L_CURLY@[9; 10) "{"

+        WHITESPACE@[10; 11) "\n"

+        R_CURLY@[11; 12) "}"

 "#

             .trim()

         );

@@ -325,10 +330,11 @@ SOURCE_FILE@[0; 25)
       L_PAREN@[6; 7) "("

       R_PAREN@[7; 8) ")"

     WHITESPACE@[8; 9) " "

-    BLOCK@[9; 12)

-      L_CURLY@[9; 10) "{"

-      WHITESPACE@[10; 11) "\n"

-      R_CURLY@[11; 12) "}"

+    BLOCK_EXPR@[9; 12)

+      BLOCK@[9; 12)

+        L_CURLY@[9; 10) "{"

+        WHITESPACE@[10; 11) "\n"

+        R_CURLY@[11; 12) "}"

   WHITESPACE@[12; 13) "\n"

   FN_DEF@[13; 25)

     FN_KW@[13; 15) "fn"

@@ -339,10 +345,11 @@ SOURCE_FILE@[0; 25)
       L_PAREN@[19; 20) "("

       R_PAREN@[20; 21) ")"

     WHITESPACE@[21; 22) " "

-    BLOCK@[22; 25)

-      L_CURLY@[22; 23) "{"

-      WHITESPACE@[23; 24) "\n"

-      R_CURLY@[24; 25) "}"

+    BLOCK_EXPR@[22; 25)

+      BLOCK@[22; 25)

+        L_CURLY@[22; 23) "{"

+        WHITESPACE@[23; 24) "\n"

+        R_CURLY@[24; 25) "}"

 "#

             .trim()

         );

diff --git a/crates/ra_mbe/src/tests.rs b/crates/ra_mbe/src/tests.rs
index 1dbf22997..034ea639b 100644
--- a/crates/ra_mbe/src/tests.rs
+++ b/crates/ra_mbe/src/tests.rs
@@ -678,21 +678,22 @@ fn test_expr_order() {
     PARAM_LIST@[5; 7)
       L_PAREN@[5; 6) "("
       R_PAREN@[6; 7) ")"
-    BLOCK@[7; 15)
-      L_CURLY@[7; 8) "{"
-      EXPR_STMT@[8; 14)
-        BIN_EXPR@[8; 13)
-          BIN_EXPR@[8; 11)
-            LITERAL@[8; 9)
-              INT_NUMBER@[8; 9) "1"
-            PLUS@[9; 10) "+"
-            LITERAL@[10; 11)
-              INT_NUMBER@[10; 11) "1"
-          STAR@[11; 12) "*"
-          LITERAL@[12; 13)
-            INT_NUMBER@[12; 13) "2"
-        SEMI@[13; 14) ";"
-      R_CURLY@[14; 15) "}""#,
+    BLOCK_EXPR@[7; 15)
+      BLOCK@[7; 15)
+        L_CURLY@[7; 8) "{"
+        EXPR_STMT@[8; 14)
+          BIN_EXPR@[8; 13)
+            BIN_EXPR@[8; 11)
+              LITERAL@[8; 9)
+                INT_NUMBER@[8; 9) "1"
+              PLUS@[9; 10) "+"
+              LITERAL@[10; 11)
+                INT_NUMBER@[10; 11) "1"
+            STAR@[11; 12) "*"
+            LITERAL@[12; 13)
+              INT_NUMBER@[12; 13) "2"
+          SEMI@[13; 14) ";"
+        R_CURLY@[14; 15) "}""#,
     );
 }
 
diff --git a/crates/ra_syntax/src/ast/expr_extensions.rs b/crates/ra_syntax/src/ast/expr_extensions.rs
index 1324965cf..25dbd0bed 100644
--- a/crates/ra_syntax/src/ast/expr_extensions.rs
+++ b/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" };"#);