dev(hansbug): add more test of t.a & t.b & t.c

test/tree/tree/test_structural.py

@@ -2,6 +2,7 @@ from collections import namedtuple
 
 import pytest
 
+from treevalue import FastTreeValue
 from treevalue.tree import TreeValue, mapping, union, raw, subside, rise, delayed
 
 
@@ -124,12 +125,18 @@ class TestTreeTreeStructural:
             MyTreeValue({'x': 4, 'y': 5, 'z': {'v': 6}}),
             MyTreeValue({'x': 7, 'y': 8, 'z': {'v': 9}}),
         )
-        assert subside(a) == MyTreeValue({
+        t5 = subside(a)
+        assert t5 == MyTreeValue({
             'x': nt(1, 4, 7),
             'y': nt(2, 5, 8),
             'z': {'v': nt(3, 6, 9), },
         })
 
+        t6 = subside(a, return_type=FastTreeValue)
+        assert t6.a == FastTreeValue({'x': 1, 'y': 2, 'z': {'v': 3}})
+        assert t6.b == FastTreeValue({'x': 4, 'y': 5, 'z': {'v': 6}})
+        assert t6.c == FastTreeValue({'x': 7, 'y': 8, 'z': {'v': 9}})
+
     def test_subside_delayed(self):
         class MyTreeValue(TreeValue):
             pass