yamlpath: handle interceding list comments correctly (#25)

Author: woodruffw

yamlpath/src/lib.rs

@@ -545,12 +545,17 @@ impl Document {
             return Err(QueryError::ExhaustedList(idx, children.len()));
         };
 
+        // If we're in a block_sequence, there's an intervening `block_sequence_item`
+        // getting in the way of our `block_node`/`flow_node`.
         if child.kind_id() == self.block_sequence_item_id {
-            // If we're in a block_sequence, there's an intervening `block_sequence_item`
-            // getting in the way of our `flow_node`.
-            return child.named_child(0).ok_or_else(|| {
-                QueryError::MissingChild(child.kind().into(), "block_sequence_item".into())
-            });
+            // NOTE: We can't just get the first named child here, since there might
+            // be interceding comments.
+            return child
+                .named_children(&mut cur)
+                .find(|c| c.kind_id() == self.block_node_id || c.kind_id() == self.flow_node_id)
+                .ok_or_else(|| {
+                    QueryError::MissingChild(child.kind().into(), "block_sequence_item".into())
+                });
         } else if child.kind_id() == self.flow_pair_id {
             // Similarly, if our index happens to be a `flow_pair`, we need to
             // get the `value` child to get the next `flow_node`.

yamlpath/tests/testcases/interceding-comment.yml

@@ -0,0 +1,25 @@
+testcase:
+  foo:
+    - # hello!
+      bar: baz
+
+  multiple:
+    - # comment 1
+      # comment 2
+      bar: baz
+
+  many-children:
+    - # foo
+      foo: bar
+    - # bar
+      bar: baz
+
+queries:
+  - query: [foo, 0, bar]
+    expected: "      bar: baz"
+
+  - query: [multiple, 0, bar]
+    expected: "      bar: baz"
+
+  - query: [many-children, 1, bar]
+    expected: "      bar: baz"