test: add tests for PyTreeSpec.__new__()

tests/test_treespec.py

@@ -42,6 +42,70 @@
 )
 
 
+def test_treespec_new():
+    with pytest.raises(TypeError):
+        optree.PyTreeSpec()
+
+    message_regex = r'The tree node traversal is empty\. \((function `.*` )?at file .*:\d+\)'
+
+    treespec = optree.PyTreeSpec.__new__(optree.PyTreeSpec)
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec.num_nodes
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec.num_children
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec.num_leaves
+    assert treespec.none_is_leaf is False
+    assert treespec.namespace == ''
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec.type
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec.kind
+
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec.paths()
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec.accessors()
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec.entries()
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec.entry(0)
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec.children()
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec.child(0)
+
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec.is_leaf()
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec.is_prefix(optree.treespec_leaf(), strict=True)
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec.is_prefix(optree.treespec_leaf(), strict=False)
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec.is_suffix(optree.treespec_leaf(), strict=True)
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec.is_suffix(optree.treespec_leaf(), strict=False)
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec == optree.treespec_leaf()
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec != optree.treespec_leaf()
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec < optree.treespec_leaf()
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec <= optree.treespec_leaf()
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec > optree.treespec_leaf()
+    with pytest.raises(SystemError, match=message_regex):
+        _ = treespec >= optree.treespec_leaf()
+
+    with pytest.raises(SystemError, match=message_regex):
+        _ = repr(treespec)
+    with pytest.raises(SystemError, match=message_regex):
+        _ = hash(treespec)
+    with pytest.raises(SystemError, match=message_regex):
+        _ = len(treespec)
+
+
 def test_treespec_equal_hash():
     for i, tree1 in enumerate(TREES):
         treespec1 = optree.tree_structure(tree1)