I denne udfordring skal du anvende din forståelse af Pythons testframeworks ved at implementere og teste en simpel lommeregner-klasse. Din lommeregner skal understøtte fire grundlæggende operationer: addition, subtraktion, multiplikation og division. Du skal bruge `unittest`-frameworket til at skrive omfattende tests, der verificerer korrektheden af hver operation.

Husk at designe dine tests, så hver metode i lommeregneren er dækket, inklusive kontrol af normal funktion og grænsetilfælde som division med nul.


import unittest
import user_code
import ast
import re   
import importlib
import csv
import unittest
import importlib

class TestTask(unittest.TestCase):
    def setUp(self):
        self.user_code = importlib.import_module("user_code")
        importlib.reload(self.user_code)
        self.Calc = getattr(self.user_code, "Calculator", None)

    def test_add_positive_and_negative(self):
        calc = self.Calc()
        _dynamic_test(
            self,
            calc.add(2, 3) == 5 and calc.add(-2, -3) == -5,
            "Add method returns correct sums for positive and negative integers",
            f"Add method failed: got {calc.add(2,3)} for (2,3), {calc.add(-2,-3)} for (-2,-3)",
        )

    def test_subtract_positive_and_negative(self):
        calc = self.Calc()
        _dynamic_test(
            self,
            calc.subtract(5, 3) == 2 and calc.subtract(-2, -3) == 1,
            "Subtract method returns correct results for positive and negative integers",
            f"Subtract method failed: got {calc.subtract(5,3)} for (5,3), {calc.subtract(-2,-3)} for (-2,-3)",
        )

    def test_multiply_positive_and_zero(self):
        calc = self.Calc()
        _dynamic_test(
            self,
            calc.multiply(4, 3) == 12 and calc.multiply(0, 5) == 0,
            "Multiply method returns correct product for positive integers and zero",
            f"Multiply method failed: got {calc.multiply(4,3)} for (4,3), {calc.multiply(0,5)} for (0,5)",
        )

    def test_divide_integer_and_float(self):
        calc = self.Calc()
        _dynamic_test(
            self,
            calc.divide(10, 2) == 5 and calc.divide(7, 2) == 3.5,
            "Divide method returns correct quotient for integer and floating-point division",
            f"Divide method failed: got {calc.divide(10,2)} for (10,2), {calc.divide(7,2)} for (7,2)",
        )

    def test_divide_by_zero(self):
        calc = self.Calc()
        try:
            calc.divide(5, 0)
            _dynamic_test(
                self,
                False,
                "Divide method raises ZeroDivisionError when dividing by zero",
                "Divide method did not raise ZeroDivisionError when dividing by zero",
            )
        except ZeroDivisionError:
            _dynamic_test(
                self,
                True,
                "Divide method raises ZeroDivisionError when dividing by zero",
                "Divide method did not raise ZeroDivisionError when dividing by zero",
            )

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()


test_main.py

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Challenge: Test en lommeregnerklasse

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