test: wait for the expected basic block filter index in interface_rest

Author: brunoerg

test/functional/interface_rest.py

@@ -288,6 +288,10 @@ def run_test(self):
 
         # See if we can get 5 headers in one response
         self.generate(self.nodes[1], 5)
+        expected_filter = {
+            'basic block filter index': {'synced': True, 'best_block_height': 208},
+        }
+        self.wait_until(lambda: self.nodes[0].getindexinfo() == expected_filter)
         json_obj = self.test_rest_request(f"/headers/{bb_hash}", query_params={"count": 5})
         assert_equal(len(json_obj), 5)  # now we should have 5 header objects
         json_obj = self.test_rest_request(f"/blockfilterheaders/basic/{bb_hash}", query_params={"count": 5})