fix(lib): correct next sibling of zero width node

Author: WillLillis

cli/src/tests/node_test.rs

@@ -306,6 +306,33 @@ fn test_parent_of_zero_width_node() {
     assert_eq!(parent, script_element);
 }
 
+#[test]
+fn test_next_sibling_of_zero_width_node() {
+    let grammar_json = load_grammar_file(
+        &fixtures_dir()
+            .join("test_grammars")
+            .join("next_sibling_from_zwt")
+            .join("grammar.js"),
+        None,
+    )
+    .unwrap();
+
+    let (parser_name, parser_code) = generate_parser_for_grammar(&grammar_json).unwrap();
+
+    let mut parser = Parser::new();
+    let language = get_test_language(&parser_name, &parser_code, None);
+    parser.set_language(&language).unwrap();
+
+    let tree = parser.parse("abdef", None).unwrap();
+
+    let root_node = tree.root_node();
+    let missing_c = root_node.child(2).unwrap();
+    assert!(missing_c.is_missing());
+    assert_eq!(missing_c.kind(), "c");
+    let node_d = root_node.child(3).unwrap();
+    assert_eq!(missing_c.next_sibling().unwrap(), node_d);
+}
+
 #[test]
 fn test_node_field_name_for_child() {
     let mut parser = Parser::new();

lib/src/node.c

@@ -263,8 +263,8 @@ static inline TSNode ts_node__next_sibling(TSNode self, bool include_anonymous)
     TSNode child;
     NodeChildIterator iterator = ts_node_iterate_children(&node);
     while (ts_node_child_iterator_next(&iterator, &child)) {
-      if (iterator.position.bytes < target_end_byte) continue;
-      if (ts_node_start_byte(child) <= ts_node_start_byte(self)) {
+      if (iterator.position.bytes <= target_end_byte) continue;
+      if (ts_node_start_byte(child) < ts_node_start_byte(self)) {
         if (ts_node__subtree(child).ptr != ts_node__subtree(self).ptr) {
           child_containing_target = child;
         }
@@ -541,8 +541,8 @@ TSNode ts_node_parent(TSNode self) {
   if (node.id == self.id) return ts_node__null();
 
   while (true) {
-    TSNode next_node = ts_node_child_containing_descendant(node, self);
-    if (ts_node_is_null(next_node)) break;
+    TSNode next_node = ts_node_child_with_descendant(node, self);
+    if (next_node.id == self.id || ts_node_is_null(next_node)) break;
     node = next_node;
   }
 

test/fixtures/test_grammars/next_sibling_from_zwt/corpus.txt

@@ -0,0 +1,10 @@
+===========================
+missing c node
+===========================
+
+abdef
+
+---
+
+(source
+    (MISSING "c"))

test/fixtures/test_grammars/next_sibling_from_zwt/grammar.js

@@ -0,0 +1,22 @@
+module.exports = grammar({
+  name: "next_sibling_from_zwt",
+  extras: $ => [
+    /\s|\\\r?\n/,
+  ],
+
+  rules: {
+    source: $ => seq(
+      'a',
+      $._bc,
+      'd',
+      'e',
+      'f',
+    ),
+
+    _bc: $ => seq(
+      'b',
+      'c',
+    ),
+  }
+});
+