Fixed whitespace bug

Author: edwin0cheng

crates/ra_mbe/src/syntax_bridge.rs

@@ -388,11 +388,12 @@ impl<'a> TreeSink for TtTreeSink<'a> {
             return;
         }
 
+        let mut last = self.cursor;
         for _ in 0..n_tokens {
             if self.cursor.eof() {
                 break;
             }
-
+            last = self.cursor;
             let text: SmolStr = match self.cursor.token_tree() {
                 Some(tt::TokenTree::Leaf(leaf)) => {
                     // Mark the range if needed
@@ -441,11 +442,11 @@ impl<'a> TreeSink for TtTreeSink<'a> {
         self.inner.token(kind, text);
 
         // Add whitespace between adjoint puncts
-        let next = self.cursor.bump();
+        let next = last.bump();
         if let (
             Some(tt::TokenTree::Leaf(tt::Leaf::Punct(curr))),
             Some(tt::TokenTree::Leaf(tt::Leaf::Punct(_))),
-        ) = (self.cursor.token_tree(), next.token_tree())
+        ) = (last.token_tree(), next.token_tree())
         {
             if curr.spacing == tt::Spacing::Alone {
                 self.inner.token(WHITESPACE, " ".into());

crates/ra_mbe/src/tests.rs

@@ -838,6 +838,37 @@ fn test_tt_composite() {
     .assert_expand_items(r#"foo! { => }"#, r#"0"#);
 }
 
+#[test]
+fn test_tt_composite2() {
+    let node = parse_macro(
+        r#"
+            macro_rules! foo {
+                ($($tt:tt)*) => { abs!(=> $($tt)*) }
+            }
+    "#,
+    )
+    .expand_items(r#"foo!{#}"#);
+
+    let res = format!("{:#?}", &node);
+    assert_eq_text!(
+        res.trim(),
+        r###"MACRO_ITEMS@[0; 10)
+  MACRO_CALL@[0; 10)
+    PATH@[0; 3)
+      PATH_SEGMENT@[0; 3)
+        NAME_REF@[0; 3)
+          IDENT@[0; 3) "abs"
+    EXCL@[3; 4) "!"
+    TOKEN_TREE@[4; 10)
+      L_PAREN@[4; 5) "("
+      EQ@[5; 6) "="
+      R_ANGLE@[6; 7) ">"
+      WHITESPACE@[7; 8) " "
+      POUND@[8; 9) "#"
+      R_PAREN@[9; 10) ")""###
+    );
+}
+
 #[test]
 fn test_lifetime() {
     parse_macro(