test_cases.py

import pytest
from binarytree import build
from exercise_bst import is_search_tree


class TestTree:

    def __init__(self, name, root):
        self.name = name
        self.root = root

    def __repr__(self):
        return self.name

    def __str__(self):
        return 'The tree \"%s\" is%s sorted:' % \
            (self.name, ('' if self.root.is_bst else ' not')) + \
            self.root.__str__()


test_trees = [
    TestTree('Linear', build([1, 2, 3, 4, 5, 6, 7])),
    TestTree('Sorted', build([4, 2, 6, 1, 3, 5, 7])),
    TestTree('Sort-ish', build([4, 2, 6, 1, 5, 3, 7]))
]


@pytest.mark.parametrize("tt", test_trees)
def test_if_search_tree(tt):
    assert is_search_tree(tt.root) == tt.root.is_bst, f"Pretty Printed Tree: {tt}"