Fix a bunch of false-positives in join-lines

crates/ra_fmt/src/lib.rs

@@ -57,7 +57,7 @@ pub fn extract_trivial_expression(block: &ast::BlockExpr) -> Option<ast::Expr> {
             return None;
         }
         return Some(expr);
-    } else {
+    }
     // Unwrap `{ continue; }`
     let (stmt,) = block.statements().next_tuple()?;
     if let ast::Stmt::ExprStmt(expr_stmt) = stmt {
@@ -70,7 +70,6 @@ pub fn extract_trivial_expression(block: &ast::BlockExpr) -> Option<ast::Expr> {
             _ => (),
         }
     }
-    }
     None
 }
 

crates/ra_ide/src/join_lines.rs

@@ -131,6 +131,9 @@ fn has_comma_after(node: &SyntaxNode) -> bool {
 fn join_single_expr_block(edit: &mut TextEditBuilder, token: &SyntaxToken) -> Option<()> {
     let block = ast::Block::cast(token.parent())?;
     let block_expr = ast::BlockExpr::cast(block.syntax().parent()?)?;
+    if !block_expr.is_standalone() {
+        return None;
+    }
     let expr = extract_trivial_expression(&block_expr)?;
 
     let block_range = block_expr.syntax().text_range();
@@ -662,4 +665,67 @@ fn main() {
         ",
         )
     }
+
+    #[test]
+    fn join_lines_mandatory_blocks_block() {
+        check_join_lines(
+            r"
+<|>fn foo() {
+    92
+}
+        ",
+            r"
+<|>fn foo() { 92
+}
+        ",
+        );
+
+        check_join_lines(
+            r"
+fn foo() {
+    <|>if true {
+        92
+    }
+}
+        ",
+            r"
+fn foo() {
+    <|>if true { 92
+    }
+}
+        ",
+        );
+
+        check_join_lines(
+            r"
+fn foo() {
+    <|>loop {
+        92
+    }
+}
+        ",
+            r"
+fn foo() {
+    <|>loop { 92
+    }
+}
+        ",
+        );
+
+        check_join_lines(
+            r"
+fn foo() {
+    <|>unsafe {
+        92
+    }
+}
+        ",
+            r"
+fn foo() {
+    <|>unsafe { 92
+    }
+}
+        ",
+        );
+    }
 }

crates/ra_syntax/src/ast/expr_extensions.rs

@@ -368,12 +368,15 @@ impl ast::BlockExpr {
     /// const FOO: () = { stand_alone };
     /// ```
     pub fn is_standalone(&self) -> bool {
+        if self.unsafe_token().is_some() || self.async_token().is_some() {
+            return false;
+        }
         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,
+            FN_DEF | IF_EXPR | WHILE_EXPR | LOOP_EXPR | TRY_BLOCK_EXPR => false,
             _ => true,
         }
     }

crates/ra_syntax/src/ast/generated/nodes.rs

@@ -554,6 +554,7 @@ impl ast::AttrsOwner for BlockExpr {}
 impl BlockExpr {
     pub fn label(&self) -> Option<Label> { support::child(&self.syntax) }
     pub fn unsafe_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![unsafe]) }
+    pub fn async_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![async]) }
     pub fn block(&self) -> Option<Block> { support::child(&self.syntax) }
 }
 

xtask/src/ast_src.rs

@@ -451,7 +451,7 @@ pub(crate) const AST_SRC: AstSrc = AstSrc {
         struct ContinueExpr: AttrsOwner { T![continue], T![lifetime] }
         struct BreakExpr: AttrsOwner { T![break], T![lifetime], Expr }
         struct Label { T![lifetime] }
-        struct BlockExpr: AttrsOwner { Label, T![unsafe], Block  }
+        struct BlockExpr: AttrsOwner { Label, T![unsafe], T![async], Block  }
         struct ReturnExpr: AttrsOwner { Expr }
         struct CallExpr: ArgListOwner { Expr }
         struct MethodCallExpr: AttrsOwner, ArgListOwner {