From 48c0a9fbd736a9c0f01931b3c9192fbd0214d6d8 Mon Sep 17 00:00:00 2001
From: James Brown <roguelazer@roguelazer.com>
Date: Tue, 11 Jun 2024 16:08:31 -0700
Subject: [PATCH] add in_subtree_of? helper function, for symmetry

---
 README.md                            | 2 +-
 lib/ancestry/instance_methods.rb     | 4 ++++
 test/concerns/tree_predicate_test.rb | 4 ++++
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 1546cfa0..68ccb928 100644
--- a/README.md
+++ b/README.md
@@ -151,7 +151,7 @@ The yellow nodes are those returned by the method.
 | includes self                 |self..indirects                                      |root..self                       |
 |`sibling_ids`                  |`subtree_ids`                                        |`path_ids`                       |
 |`has_siblings?`                |                                                     |                                 |
-|`sibling_of?(node)`            |                                                     |                                 |
+|`sibling_of?(node)`            |`in_subtree_of?`                                     |                                 |
 
 When using `STI` all classes are returned from the scopes unless you specify otherwise using `where(:type => "ChildClass")`.
 
diff --git a/lib/ancestry/instance_methods.rb b/lib/ancestry/instance_methods.rb
index 331446ea..8d898093 100644
--- a/lib/ancestry/instance_methods.rb
+++ b/lib/ancestry/instance_methods.rb
@@ -303,6 +303,10 @@ def subtree_ids depth_options = {}
       subtree(depth_options).pluck(self.class.primary_key)
     end
 
+    def in_subtree_of?(node)
+      id == node.id || descendant_of?(node)
+    end
+
     # Callback disabling
 
     def without_ancestry_callbacks
diff --git a/test/concerns/tree_predicate_test.rb b/test/concerns/tree_predicate_test.rb
index 4a3eed85..c57d6304 100644
--- a/test/concerns/tree_predicate_test.rb
+++ b/test/concerns/tree_predicate_test.rb
@@ -31,6 +31,10 @@ def test_tree_predicates
         # Descendants assertions
         assert children.map { |n| !root.descendant_of?(n) }.all?
         assert children.map { |n| n.descendant_of?(root) }.all?
+        # Subtrees assertions
+        assert children.map { |n| n.in_subtree_of?(root) }.all?
+        assert children.map { |n| !root.in_subtree_of?(n) }.all?
+        assert root.in_subtree_of?(root)
       end
     end
   end