
import unittest
import user_code
import ast
import re   
import importlib

class TestTask(unittest.TestCase):
    def test_rectangle_instance_attributes(self):
        import user_code
        importlib.reload(user_code)
        r1 = user_code.Rectangle("rect01", 5, 10)
        r2 = user_code.Rectangle("rect02", 3, 7)
        _dynamic_test(
            self,
            hasattr(r1, 'shape_id') and hasattr(r1, 'width') and hasattr(r1, 'height'),
            "Rectangle instance has required attributes.",
            "Rectangle instance missing required attributes."
        )
        _dynamic_test(
            self,
            r1.shape_id == "rect01" and r2.shape_id == "rect02",
            "Each rectangle has unique shape_id.",
            f"Expected r1.shape_id='rect01', r2.shape_id='rect02', got r1.shape_id={r1.shape_id}, r2.shape_id={r2.shape_id}."
        )
        _dynamic_test(
            self,
            r1.width == 5 and r1.height == 10 and r2.width == 3 and r2.height == 7,
            "Rectangle dimensions are unique per instance.",
            f"Expected r1=(5,10), r2=(3,7), got r1=({r1.width},{r1.height}), r2=({r2.width},{r2.height})."
        )

    def test_unit_is_class_attribute(self):
        import user_code
        importlib.reload(user_code)
        r = user_code.Rectangle("r", 1, 1)
        _dynamic_test(
            self,
            hasattr(user_code.Rectangle, 'unit'),
            "Class attribute 'unit' exists on Rectangle.",
            "Class attribute 'unit' missing from Rectangle."
        )
        _dynamic_test(
            self,
            not hasattr(r, 'unit') or getattr(r, 'unit') == user_code.Rectangle.unit,
            "Rectangle instance does not override 'unit'.",
            "Rectangle instance should not have its own 'unit' attribute."
        )

    def test_area_rectangle(self):
        import user_code
        importlib.reload(user_code)
        r = user_code.Rectangle("rtest", 2.5, 4)
        result = r.area()
        expected_value = round(2.5 * 4, 2)
        expected = f"Area: {expected_value} {user_code.Rectangle.unit}"
        _dynamic_test(
            self,
            isinstance(result, str) and expected in result,
            "Rectangle.area() returns correct formatted string.",
            f"Expected '{expected}', got '{result}'."
        )

    def test_unit_modification_on_class(self):
        import user_code
        importlib.reload(user_code)
        user_code.Rectangle.unit = "m^2"
        r = user_code.Rectangle("rmod", 1, 5)
        _dynamic_test(
            self,
            r.area().endswith("m^2"),
            "Changing 'unit' on class updates all instances.",
            f"Expected area() to end with 'm^2', got r: {r.area()}."
        )

    def test_unit_modification_on_instance(self):
        import user_code
        importlib.reload(user_code)
        r = user_code.Rectangle("rinst", 2, 2)
        setattr(r, 'unit', 'ft^2')
        # Changing on instance should not affect class or other instances
        r2 = user_code.Rectangle("rinst2", 1, 1)
        _dynamic_test(
            self,
            user_code.Rectangle.unit == "cm^2",
            "Class attribute 'unit' remains unchanged after instance assignment.",
            f"Class attribute 'unit' should remain 'cm^2', got Rectangle.unit={user_code.Rectangle.unit}."
        )
        _dynamic_test(
            self,
            r2.area().endswith("cm^2"),
            "Other instances are not affected by instance attribute assignment.",
            f"Expected area() to end with 'cm^2', got r2: {r2.area()}."
        )

def _dynamic_test(test_case, condition, success_message, failure_message):
    if condition:
        test_case._testMethodName = success_message
        test_case.assertTrue(True, success_message)
    else:
        test_case._testMethodName = failure_message
        test_case.fail(failure_message)

def normalize_text(text):
    text = text.lower()
    text = re.sub(r"\\s{2,}", " ", text)
    text = re.sub(r"\\s*([,:?])\\s*", r"\\1 ", text)
    return text.strip()

def change_var(code: str, var_name: str, value: str) -> str:
    tree = ast.parse(code)
    lines = code.splitlines()
    changed = False
    # Collect all assignment nodes to modify
    assign_nodes = [
        (i, node)
        for i, node in enumerate(tree.body)
        if isinstance(node, ast.Assign)
        and any(isinstance(target, ast.Name) and target.id == var_name for target in node.targets)
    ]

    # If nothing to change, return unmodified code
    if not assign_nodes:
        return code

    # Perform replacements for all matching assignments (from last to first to not break line offsets)
    for i, node in reversed(assign_nodes):
        start_line = node.lineno - 1
        line = lines[start_line]
        indent = ' ' * (len(line) - len(line.lstrip()))
        lines[start_line] = f"{indent}{var_name} = {value}"
        next_line = len(lines)
        for next_node in tree.body[i+1:]:
            if hasattr(next_node, 'lineno'):
                next_line = next_node.lineno - 1
                break
        if next_line > start_line + 1:
            lines[start_line+1:next_line] = []
        changed = True

    return '\\n'.join(lines) if changed else code


if __name__ == '__main__':
    unittest.main()

Challenge: Shape Area Calculations

解答