From ea515b69679593c93b542e06ba86cab83f87ea02 Mon Sep 17 00:00:00 2001
From: Max Brunsfeld <maxbrunsfeld@gmail.com>
Date: Thu, 18 Jul 2019 12:39:12 -0700
Subject: [PATCH] Fix ts_node_string behavior for anonymous leaf nodes

Refs tree-sitter/py-tree-sitter#8
---
 cli/src/tests/node_test.rs | 17 +++++++++++++++++
 lib/src/subtree.c          | 16 ++++++++++------
 2 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/cli/src/tests/node_test.rs b/cli/src/tests/node_test.rs
index 431267b9..4cf9fc13 100644
--- a/cli/src/tests/node_test.rs
+++ b/cli/src/tests/node_test.rs
@@ -419,6 +419,23 @@ fn test_node_is_extra() {
     assert!(comment_node.is_extra());
 }
 
+#[test]
+fn test_node_sexp() {
+    let mut parser = Parser::new();
+    parser.set_language(get_language("javascript")).unwrap();
+    let tree = parser.parse("if (a) b", None).unwrap();
+    let root_node = tree.root_node();
+    let if_node = root_node.descendant_for_byte_range(0, 0).unwrap();
+    let paren_node = root_node.descendant_for_byte_range(3, 3).unwrap();
+    let identifier_node = root_node.descendant_for_byte_range(4, 4).unwrap();
+    assert_eq!(if_node.kind(), "if");
+    assert_eq!(if_node.to_sexp(), "(\"if\")");
+    assert_eq!(paren_node.kind(), "(");
+    assert_eq!(paren_node.to_sexp(), "(\"(\")");
+    assert_eq!(identifier_node.kind(), "identifier");
+    assert_eq!(identifier_node.to_sexp(), "(identifier)");
+}
+
 #[test]
 fn test_node_field_names() {
     let (parser_name, parser_code) = generate_parser_for_grammar(
diff --git a/lib/src/subtree.c b/lib/src/subtree.c
index a7521fa3..2e7d05a7 100644
--- a/lib/src/subtree.c
+++ b/lib/src/subtree.c
@@ -816,16 +816,16 @@ static size_t ts_subtree__write_to_string(
 
   char *cursor = string;
   char **writer = (limit > 0) ? &cursor : &string;
-  bool visible =
+  bool is_root = field_name == ROOT_FIELD;
+  bool is_visible =
     include_all ||
     alias_is_named ||
     ts_subtree_missing(self) ||
     (ts_subtree_visible(self) && ts_subtree_named(self));
 
-  if (visible) {
-    if (field_name != ROOT_FIELD) {
+  if (is_visible) {
+    if (!is_root) {
       cursor += snprintf(*writer, limit, " ");
-
       if (field_name) {
         cursor += snprintf(*writer, limit, "%s: ", field_name);
       }
@@ -848,6 +848,10 @@ static size_t ts_subtree__write_to_string(
         cursor += snprintf(*writer, limit, "(%s", symbol_name);
       }
     }
+  } else if (is_root) {
+    TSSymbol symbol = ts_subtree_symbol(self);
+    const char *symbol_name = ts_language_symbol_name(language, symbol);
+    cursor += snprintf(*writer, limit, "(\"%s\")", symbol_name);
   }
 
   if (ts_subtree_child_count(self)) {
@@ -877,7 +881,7 @@ static size_t ts_subtree__write_to_string(
           ? ts_language_symbol_metadata(language, alias_symbol).named
           : false;
 
-        const char *child_field_name = visible ? NULL : field_name;
+        const char *child_field_name = is_visible ? NULL : field_name;
         for (const TSFieldMapEntry *i = field_map; i < field_map_end; i++) {
           if (!i->inherited && i->child_index == structural_child_index) {
             child_field_name = language->field_names[i->field_id];
@@ -895,7 +899,7 @@ static size_t ts_subtree__write_to_string(
     }
   }
 
-  if (visible) cursor += snprintf(*writer, limit, ")");
+  if (is_visible) cursor += snprintf(*writer, limit, ")");
 
   return cursor - string;
 }