import unittest
import subprocess

class TestOutputComparison(unittest.TestCase):

    def test_compare_output(self):
        # Define the Python script to run and the expected output file
        script_to_run = 'interpolation_error.py'  # Replace with your script's name
        expected_file = 'reference_output.txt'

        # Run the script and capture the output
        result = subprocess.run(['python3', script_to_run], capture_output=True, text=True)
        output_lines = result.stdout.splitlines()

        # Open and read the expected output file
        with open(expected_file, 'r') as expected:
            expected_lines = expected.read().splitlines()

            # Ensure the number of lines is the same
            self.assertEqual(len(output_lines), len(expected_lines), 
                             "The number of lines in the output does not match the expected output.")

            # Compare each line
            for i, (output_line, expected_line) in enumerate(zip(output_lines, expected_lines)):
                self.assertEqual(output_line.strip(), expected_line.strip(), 
                                 f"Line {i+1} does not match:\nOutput: {output_line}\nExpected: {expected_line}")

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