From 73e252e39bf85bbedc2e251a830cdedd6ab862cc Mon Sep 17 00:00:00 2001
From: Max Brunsfeld <maxbrunsfeld@gmail.com>
Date: Wed, 10 Feb 2021 16:14:24 -0800
Subject: [PATCH] Add unit test for child_by_field_name w/ hidden nodes

---
 cli/src/tests/node_test.rs | 30 ++++++++++++++++++++++++++++--
 lib/src/node.c             | 11 +++++++----
 2 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/cli/src/tests/node_test.rs b/cli/src/tests/node_test.rs
index 7e652cd5..9a47ce06 100644
--- a/cli/src/tests/node_test.rs
+++ b/cli/src/tests/node_test.rs
@@ -232,12 +232,38 @@ fn test_node_parent_of_child_by_field_name() {
     let mut parser = Parser::new();
     parser.set_language(get_language("javascript")).unwrap();
     let tree = parser.parse("foo(a().b[0].c.d.e())", None).unwrap();
-    let call_node = tree.root_node().named_child(0).unwrap().named_child(0).unwrap();
+    let call_node = tree
+        .root_node()
+        .named_child(0)
+        .unwrap()
+        .named_child(0)
+        .unwrap();
     assert_eq!(call_node.kind(), "call_expression");
 
     // Regression test - when a field points to a hidden node (in this case, `_expression`)
     // the hidden node should not be added to the node parent cache.
-    assert_eq!(call_node.child_by_field_name("function").unwrap().parent(), Some(call_node));
+    assert_eq!(
+        call_node.child_by_field_name("function").unwrap().parent(),
+        Some(call_node)
+    );
+}
+
+#[test]
+fn test_node_child_by_field_name_with_extra_hidden_children() {
+    let mut parser = Parser::new();
+    parser.set_language(get_language("python")).unwrap();
+
+    // In the Python grammar, some fields are applied to `suite` nodes,
+    // which consist of an invisible `indent` token followed by a block.
+    // Check that when searching for a child with a field name, we don't
+    //
+    let tree = parser.parse("while a:\n  pass", None).unwrap();
+    let while_node = tree.root_node().child(0).unwrap();
+    assert_eq!(while_node.kind(), "while_statement");
+    assert_eq!(
+        while_node.child_by_field_name("body").unwrap(),
+        while_node.child(3).unwrap(),
+    );
 }
 
 #[test]
diff --git a/lib/src/node.c b/lib/src/node.c
index e5710922..8498f9c5 100644
--- a/lib/src/node.c
+++ b/lib/src/node.c
@@ -561,11 +561,14 @@ recur:
         return child;
       }
 
-      // If the field refers to a hidden node, return its first visible
-      // child.
+      // If the field refers to a hidden node with visible children,
+      // return the first visible child.
+      else if (ts_node_child_count(child) > 0 ) {
+        return ts_node_child(child, 0);
+      }
+
+      // Otherwise, continue searching subsequent children.
       else {
-        TSNode result = ts_node_child(child, 0);
-        if (result.id) return result;
         field_map++;
         if (field_map == field_map_end) return ts_node__null();
       }