"""Comprueba lo que los apuntes afirman sobre los programas de la semana 10.""" import pathlib import re import subprocess import tempfile import unittest HERE = pathlib.Path(__file__).parent BUILD = HERE / "build" FLAGS = ["-Wall", "-Wextra", "-std=c17"] SANITIZE = ["-g", "-fsanitize=address,undefined"] def execute(command, stdin=""): done = subprocess.run( command, input=stdin, encoding="utf-8", errors="replace", stdout=subprocess.PIPE, stderr=subprocess.STDOUT, timeout=10, ) return done.stdout, done.returncode def run(program, stdin=""): """Ejecuta un programa de build/; devuelve su salida (con errores) y su estado.""" return execute([str(BUILD / program)], stdin) def build_source(source, *extra): """Compila un archivo; devuelve los mensajes, el estado y el ejecutable.""" out = pathlib.Path(tempfile.mkdtemp()) / pathlib.Path(source).stem done = subprocess.run( ["gcc", *FLAGS, *extra, source, "-o", str(out)], cwd=HERE, encoding="utf-8", stdout=subprocess.PIPE, stderr=subprocess.STDOUT, ) return done.stdout, done.returncode, out class CleanCompile(unittest.TestCase): def test_examples_have_no_warnings(self): for source in sorted(HERE.glob("*.c")): with self.subTest(source=source.name): done = subprocess.run( ["gcc", *FLAGS, "-Werror", "-fsyntax-only", str(source)], text=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, ) self.assertEqual(done.returncode, 0, done.stdout) def test_string_h_is_not_used_yet(self): for source in list(HERE.glob("*.c")) + list((HERE / "errors").glob("*.c")): with self.subTest(source=source.name): self.assertNotIn("string.h", source.read_text(encoding="utf-8")) class ArraysInFunctions(unittest.TestCase): def test_sum_uses_the_length_it_receives(self): self.assertEqual(run("sum_array"), ( "Suma de las 5 notas: 71\nPromedio: 14.20\nSuma de las 3 primeras: 40\n", 0)) def test_function_changes_array_but_not_int(self): self.assertEqual(run("bonus"), ("grade: 14\ngrades: 16 11 19\n", 0)) def test_function_sees_the_same_address(self): output, _ = run("same_address") addresses = re.findall(r"0x[0-9a-f]+", output) self.assertEqual(len(addresses), 2) self.assertEqual(addresses[0], addresses[1]) def test_sizeof_of_parameter(self): messages, status, binary = build_source("errors/sizeof_param.c") self.assertEqual(status, 0) self.assertEqual(messages.count("-Wsizeof-array-argument"), 2) output, _ = execute([str(binary)]) sizes = re.findall(r"(\d+) bytes", output) self.assertEqual(sizes[0], "20") # 5 int de 4 bytes en este entorno self.assertEqual(sizes[1], sizes[2]) # el 5 del parámetro no cambia nada self.assertNotEqual(sizes[1], "20") def test_const_is_enforced(self): messages, status, _ = build_source("errors/const_write.c") self.assertNotEqual(status, 0) self.assertIn("read-only location", messages) def test_const_accepts_a_normal_array(self): self.assertEqual(run("const_param"), ("Nota mayor: 20\n", 0)) class Vector(unittest.TestCase): def test_insert_and_remove_with_their_limits(self): expected = ["n = 3: 10 20 30", "n = 4: 10 99 20 30", "n = 5: 10 99 20 30 40", "n = 5: 10 99 20 30 40", "n = 4: 99 20 30 40", "n = 3: 99 20 30", "n = 3: 99 20 30"] output, status = run("vector") self.assertEqual((output.splitlines(), status), (expected, 0)) def test_moving_from_the_start_loses_a_value(self): _, _, binary = build_source("errors/insert_wrong.c") self.assertEqual(execute([str(binary)])[0], " 10 99 20 20\n") class Strings(unittest.TestCase): def test_array_sizes_and_bytes(self): output, _ = run("string_bytes") self.assertIn("sizeof(s) = 5\n", output) self.assertIn("s[4] = 0\n", output) self.assertIn("sizeof(t) = 8\n 104 111 108 97 0 0 0 0\n", output) self.assertIn("'\\0' vale 0 y '0' vale 48\n", output) def test_terminator_cuts_the_text_but_not_the_array(self): self.assertEqual(run("cut_string")[0], "hola\nHola\nHo\nsizeof(s) sigue siendo 5\n") def test_length_counts_bytes(self): output, status = run("my_strlen") # sus assert también corren aquí self.assertEqual(status, 0) self.assertIn('my_strlen("ano") = 3\n', output) self.assertIn('my_strlen("año") = 4\n', output) self.assertIn("my_strlen(t) = 4\nsizeof(t) = 8\n", output) def test_lowercase_ignores_utf8_with_either_char_sign(self): expected = "Hola Mundo: 7\nLIMA 2026: 0\nano: 3\naño: 2\n" self.assertEqual(run("count_lowercase")[0], expected) for flag in ["-fsigned-char", "-funsigned-char"]: with self.subTest(flag=flag): _, status, binary = build_source("count_lowercase.c", flag) self.assertEqual(status, 0) self.assertEqual(execute([str(binary)])[0], expected) def test_too_long_initializer_warns_but_one_byte_short_does_not(self): messages, _, _ = build_source("errors/too_long.c") self.assertIn("is too long", messages) messages, status, _ = build_source("errors/no_terminator.c") self.assertEqual((messages, status), ("", 0)) def test_no_terminator_is_detected_when_running(self): _, _, binary = build_source("errors/no_terminator.c", *SANITIZE) output, status = execute([str(binary)]) self.assertNotEqual(status, 0) self.assertIn("stack-buffer-overflow", output) def test_writing_a_literal_compiles_without_warnings(self): # Al correr es comportamiento indefinido: de eso no se prueba nada. messages, status, _ = build_source("errors/literal_write.c") self.assertEqual((messages, status), ("", 0)) class ReadingText(unittest.TestCase): def test_width_limits_scanf_and_stops_at_space(self): self.assertEqual(run("read_word", "Ana María\n")[0], "Primera lectura: Ana\nSegunda lectura: María\n") self.assertEqual(run("read_word", "abcdefghijklmnopqrstuvwxyz\n")[0], "Primera lectura: abcdefghijklmnopqrs\nSegunda lectura: tuvwxyz\n") self.assertEqual(run("read_word", ""), ("Entrada inválida\n", 1)) def test_fgets_four_cases(self): cases = { "Ana\n": 'leído: "Ana\\n"\nfgets devolvió NULL\n', "Ana": 'leído: "Ana"\nfgets devolvió NULL\n', "Alejandra\n": 'leído: "Alejand"\nleído: "ra\\n"\nfgets devolvió NULL\n', "": "fgets devolvió NULL\n", } for text, expected in cases.items(): with self.subTest(text=text): self.assertEqual(run("read_line", text), (expected, 0)) def test_exact_fit_leaves_the_newline_for_later(self): self.assertEqual(run("read_line", "Rosaura\n")[0], 'leído: "Rosaura"\nleído: "\\n"\nfgets devolvió NULL\n') def test_read_name(self): self.assertEqual(run("read_name", "Ana María\nLima\n"), ("Nombre: Ana María\nCiudad: Lima\n", 0)) self.assertEqual(run("read_name", "Maria de los Angeles Quispe\nLima\n"), ("Nombre: Maria de los Angele\nCiudad: Lima\n", 0)) # 19 bytes justos: el salto de línea que queda no debe llegar a la ciudad. self.assertEqual(run("read_name", "abcdefghijklmnopqrs\nLima\n"), ("Nombre: abcdefghijklmnopqrs\nCiudad: Lima\n", 0)) self.assertEqual(run("read_name", "Ana\n"), ("Entrada inválida\n", 1)) self.assertEqual(run("read_name", ""), ("Entrada inválida\n", 1)) def test_scanf_leaves_the_newline(self): _, _, binary = build_source("errors/scanf_then_fgets.c") self.assertEqual(execute([str(binary)], "18\nAna\n")[0], "Edad: 18\nNombre: \n") self.assertEqual(run("age_name", "18\nAna\n")[0], "Edad: 18\nNombre: Ana\n") class BufferOverflow(unittest.TestCase): def test_short_name_works_and_long_name_is_reported(self): messages, status, binary = build_source("errors/overflow_scanf.c", *SANITIZE) self.assertEqual((messages, status), ("", 0)) self.assertEqual(execute([str(binary)], "Ana\n"), ("Hola, Ana\n", 0)) output, status = execute([str(binary)], "Alejandra\n") self.assertNotEqual(status, 0) for fragment in ["stack-buffer-overflow", "WRITE of size 10", "overflow_scanf.c:7", "'name' (line 5)"]: self.assertIn(fragment, output) def test_overflow_demos_compile_without_warnings(self): for source in ["errors/overflow_scanf.c", "errors/overflow_neighbor.c"]: with self.subTest(source=source): messages, status, _ = build_source(source) self.assertEqual((messages, status), ("", 0)) def test_neighbor_demo_is_caught_by_the_sanitizer(self): # Sin sanitizer el resultado depende de la máquina: no se compara. _, _, binary = build_source("errors/overflow_neighbor.c", *SANITIZE) self.assertIn("Acceso normal", execute([str(binary)], "Ana\n")[0]) self.assertIn("stack-buffer-overflow", execute([str(binary)], "Alejandra_Quispe\n")[0]) def test_copy_text_stays_inside(self): self.assertEqual(run("copy_text"), ("sol\nluna\nestr\n", 0)) if __name__ == "__main__": unittest.main()