def test_for_loop(self, capsys):
line = 'for (var i = 0; i < 10; i = i + 1) print i;'
lox = Lox()
lox.run(line)
out, err = capsys.readouterr()
assert err == ''
assert out == "0.0\n1.0\n2.0\n3.0\n4.0\n5.0\n6.0\n7.0\n8.0\n9.0\n"
class LoxTests_Execute_Statements(unittest.TestCase):
def setUp(self):
self.output = TestOutputStream()
self.lox = Lox(output = self.output)
def test_print_literal(self):
self.lox.execute('print "yo";')
self.assertEqual(self.output.last_sent, "yo")
def test_if(self, capsys):
line = "var num = 9; \
if(num >= 0 and num <= 10) \
print(true);"
lox = Lox()
lox.run(line)
out, err = capsys.readouterr()
assert err == ''
assert out == "True\n"
def test_of(self, capsys):
line = 'var s = "hi"; \
if(s == "hi" or s == "hello") \
print("Greetings");'
lox = Lox()
lox.run(line)
out, err = capsys.readouterr()
assert err == ''
assert out == "Greetings\n"
def test_num_parameters(self, capsys):
line = 'fun add(a, b){ \
return(a + b); \
} \
print(add(10, 5));'
lox = Lox()
lox.run(line)
out, err = capsys.readouterr()
assert err == ''
assert out == "15.0\n"
def test_string_parameters(self, capsys):
line = 'fun strAppend(str1, str2) { \
var str = str1 + str2; \
return str;} \
print(strAppend("foo", "bar"));'
lox = Lox()
lox.run(line)
out, err = capsys.readouterr()
assert err == ''
assert out == "foobar\n"
def test_while_loop(self, capsys):
line = 'var i = 0; \
while(i < 10) { \
print(i); \
i = i + 1; \
}'
lox = Lox()
lox.run(line)
out, err = capsys.readouterr()
assert err == ''
assert out == "0.0\n1.0\n2.0\n3.0\n4.0\n5.0\n6.0\n7.0\n8.0\n9.0\n"
class LoxTests_LogicalOperators(unittest.TestCase):
def setUp(self):
self.output = TestOutputStream()
self.lox = Lox(output = self.output)
def test_print_false_and_1(self):
self.lox.execute('print false and 1;')
self.assertEqual(self.output.last_sent, False)
def test_print_true_and_1(self):
self.lox.execute('print true and 1;')
self.assertEqual(self.output.last_sent, 1)
def test_fun_with_conditional(self, capsys):
line = 'fun checkNegative(num){ \
if(num <= 0) \
return(true); \
else \
return(false); \
} \
print(checkNegative(-1));'
lox = Lox()
lox.run(line)
out, err = capsys.readouterr()
assert err == ''
assert out == "True\n"
def test_recursion(self, capsys):
line = 'fun isOdd(n) { \
if (n == 0) return false; \
return isEven(n - 1); \
} \
fun isEven(n){ \
if (n == 0) return true; \
return isOdd(n - 1); \
} \
print(isEven(3));'
lox = Lox()
lox.run(line)
out, err = capsys.readouterr()
assert err == ''
assert out == "False\n"
class LoxTests_Scoping(unittest.TestCase):
def setUp(self):
self.output = TestOutputStream()
self.lox = Lox(output = self.output)
def test_reuse_name_in_inner_scope(self):
self.lox.execute('var a = 1;')
self.lox.execute('{ var a = 2; print a; }')
self.assertEqual(self.output.last_sent, 2)
self.lox.execute('print a;')
self.assertEqual(self.output.last_sent, 1)
def test_assign_outer_in_inner_scope(self):
self.lox.execute('var a = 1;')
self.lox.execute('{ a = 2; }')
self.lox.execute('print a;')
self.assertEqual(self.output.last_sent, 2)
class LoxTests_WhileLoops(unittest.TestCase):
def setUp(self):
self.output = TestOutputStream()
self.lox = Lox(output = self.output)
def test_while_var_one_loop(self):
self.lox.execute('var do_loop = true;')
self.lox.execute('while (do_loop) { print 1; do_loop = false; }')
self.assertEqual(self.output.last_sent, 1)
def test_while_false_does_nothing(self):
self.lox.execute('while (false) print 1;')
self.assertEqual(self.output.num_sent(), 0)
def test_while_loops_multiple_times(self):
self.lox.execute('var temp = 5;')
self.lox.execute('while (temp > 0) { print 1; temp = temp - 1; }')
self.assertEqual(self.output.num_sent(), 5)
def execute(self, lox_instance: Lox, out_buf: StringIO) -> bool:
lox_instance.interpreter.reinitialize_environment()
out_capture = StringIO()
err_capture = StringIO()
with self.path.open("r") as fil:
source = fil.read()
self._compute_expected_output(source)
with suppress(LoxExit), redirect_stderr(err_capture), redirect_stdout(
out_capture):
lox_instance.run(source)
out = tuple(line.strip()
for line in out_capture.getvalue().splitlines())
err = tuple(line.strip()
for line in err_capture.getvalue().splitlines())
if not (message := self._verify(out, err)):
print(f"[{green('PASS')}]: {self.path}", file=out_buf)
return True
class LoxTests_Execute_Expressions(unittest.TestCase):
def setUp(self):
self.output = TestOutputStream()
self.lox = Lox(output = self.output)
def test_numerical(self):
params = [
('1 + 1', 2),
('2 * 2', 4),
('1 + 4 / 2', 3),
('(1 + 4) / 2', 2.5),
(""" ( 1 + 4/2) * 3*2 - 10
== ( 1 + 2) * 6 - 10 """, True),
]
for expression, expected in params:
with self.subTest():
self.lox.execute(f'print {expression};')
self.assertEqual(self.output.last_sent, expected)
def test_strings(self):
params = [
('"cat" == "cat"', True),
('"dog" == "cat"', False)
]
for expression, expected in params:
with self.subTest():
self.lox.execute(f'print {expression};')
self.assertEqual(self.output.last_sent, expected)
def test_bools(self):
params = [
('true == 1 < 2', True),
('false != 1 < 2 + 4', True)
]
for expression, expected in params:
with self.subTest():
self.lox.execute(f'print {expression};')
self.assertEqual(self.output.last_sent, expected)
def test_incomplete_expression(self):
self.lox.execute('1 +')
self.assertTrue('Expected expression' in self.output.last_sent)
def __init__(self) -> None:
self._queued_tests: List[Test] = list()
self._lox_instance = Lox(Debug.JAVA_STYLE_TOKENS
| Debug.REDUCED_ERROR_REPORTING)
self._fails_output = StringIO()
self._test_root = Path(
os.path.realpath(__file__)).parent / "test_suite"
if not self._test_root.is_dir():
raise FileNotFoundError("Test suite not found!")
print(f"Test suite discovered at '{self._test_root}'.")
ignored_paths_full = tuple(self._test_root / path
for path in self.IGNORED_PATHS)
for path in self.TEST_PATHS:
self._discover_and_queue_tests(self._test_root / path,
ignored_paths_full)
print(f"{len(self._queued_tests)} tests found.")
class LoxTests_IfElse(unittest.TestCase):
def setUp(self):
self.output = TestOutputStream()
self.lox = Lox(output = self.output)
def test_if_true_else(self):
self.lox.execute('if (true) print "true"; else print "false";')
self.assertEqual(self.output.last_sent, "true")
def test_if_false_else(self):
self.lox.execute('if (false) print "true"; else print "false";')
self.assertEqual(self.output.last_sent, "false")
def test_nested_if_else_should_grab_earliest_else(self):
self.lox.execute("""
if (true)
if (true)
print "this should get printed";
else
print "this should not get printed";
""")
self.assertEqual(self.output.last_sent, "this should get printed")
def setUp(self):
self.output = TestOutputStream()
self.lox = Lox(output = self.output)
class LoxTests_Variables(unittest.TestCase):
def setUp(self):
self.output = TestOutputStream()
self.lox = Lox(output = self.output)
def test_declare_then_print(self):
self.lox.execute('var a;')
self.lox.execute('print a;')
self.assertEqual(self.output.last_sent, "nil")
def test_declare_with_initialiser_then_print(self):
self.lox.execute('var a = 1;')
self.lox.execute('print a;')
self.assertEqual(self.output.last_sent, 1)
def test_declare_with_initialiser_expression_then_print(self):
self.lox.execute('var a = 1 + 1;')
self.lox.execute('print a;')
self.assertEqual(self.output.last_sent, 2)
def test_declare_then_assign(self):
self.lox.execute('var a = 1;')
self.lox.execute('print a;')
self.assertEqual(self.output.last_sent, 1)
self.lox.execute('a = "asdf";')
self.lox.execute('print a;')
self.assertEqual(self.output.last_sent, 'asdf')
def test_can_print_assignment(self):
# assignment is an expression, so has a value
self.lox.execute('var a = 1;')
self.lox.execute('print a = 2;')
self.assertEqual(self.output.last_sent, 2)
def test_bad_assign_target_should_print_error(self):
self.lox.execute('var a; var b;')
self.lox.execute('a + b = 3;')
self.assertIn('Invalid assignment target', self.output.last_sent)
description=
"Yet another implementation of the Lox interpreter in Python",
allow_abbrev=False)
parser.add_argument("-c",
metavar="STRING",
type=str,
required=False,
help="source string to execute")
parser.add_argument("source",
metavar="FILE",
nargs="?",
type=str,
default=None,
help="the .lox file to interpret")
parser.add_argument(
"--dbg",
choices=tuple(option.name for option in Debug),
default=list(),
action="append",
help="pylox debugging options, multiple --dbg arguments can be passed")
args, extra_args = parser.parse_known_args()
lox = Lox(reduce(lambda a, b: a | Debug[b], args.dbg,
Debug.BACKTRACE)) # Collapse all flags passed.
if args.c:
lox.run(args.c)
elif args.source:
lox.run_file(args.source)
else:
lox.run_interactive()
import sys
from pylox.lox import Lox, LoxRepl
DEBUG = False
if __name__ == "__main__":
args = sys.argv[1:] # arg 0 is the name of this script
lox = Lox(debug=DEBUG)
if len(args) == 0:
LoxRepl(lox).run()
elif len(args) == 1:
lox.run_file(args[0])
else:
print('nah')
def setUp(self):
self.output = TestOutputStream()
self.lox = Lox(output = self.output)
self.runner = LoxFileRunner(self.lox)