tamer: xir::flat: Ignore whitespace both before and after root

DEV-7145

tamer/src/xir/flat.rs

@@ -367,13 +367,15 @@ where
                 Transition(st).ok(XirfToken::Comment(sym, span))
             }
 
-            (PreRoot(_), tok @ XirToken::Open(..)) => {
-                Self::parse_node(tok, stack)
+            // Ignore whitespace before or after root.
+            (st @ (PreRoot(_) | Done), XirToken::Text(sym, _))
+                if is_whitespace(sym) =>
+            {
+                Transition(st).incomplete()
             }
 
-            // Ignore whitespace before root.
-            (st @ PreRoot(_), XirToken::Text(sym, _)) if is_whitespace(sym) => {
-                Transition(st).incomplete()
+            (PreRoot(_), tok @ XirToken::Open(..)) => {
+                Self::parse_node(tok, stack)
             }
 
             (st @ PreRoot(_), tok) => {
@@ -419,7 +421,7 @@ where
             PreRoot(_) => write!(f, "expecting document root"),
             NodeExpected => write!(f, "expecting a node"),
             AttrExpected(sa) => Display::fmt(sa, f),
-            Done => write!(f, "done parsing"),
+            Done => write!(f, "done parsing document root"),
         }
     }
 }

tamer/src/xir/flat/test.rs

@@ -449,6 +449,34 @@ fn comment_before_or_after_root_ok() {
     );
 }
 
+// Similar to above,
+//   but with whitespace.
+#[test]
+fn whitespace_before_or_after_root_ok() {
+    let name = "root";
+    let ws = "  ".unwrap_into();
+
+    let toks = [
+        XirToken::Text(ws, S),
+        xir_open(name, S2),
+        xir_close_empty(S3),
+        XirToken::Text(ws, S4),
+    ]
+    .into_iter();
+
+    let sut = parse::<1, RefinedText>(toks);
+
+    assert_eq!(
+        Ok(vec![
+            Parsed::Incomplete,
+            Parsed::Object(open(name, S2, Depth(0))),
+            Parsed::Object(close_empty(S3, Depth(0))),
+            Parsed::Incomplete,
+        ]),
+        sut.collect(),
+    );
+}
+
 // But there must be no content at the end of the document after the closing
 //   root node.
 // This does not test every applicable token;