121 lines
3.9 KiB
Python
121 lines
3.9 KiB
Python
"""Tests for calc/parser.py covering DoD gates D1–D5."""
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import unittest
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from calc.lexer import tokenize
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from calc.parser import parse, ParseError, Num, BinOp, Unary
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def p(src: str):
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"""Shorthand: tokenize then parse."""
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return parse(tokenize(src))
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class TestD1Precedence(unittest.TestCase):
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def test_mul_binds_tighter_than_add(self):
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# 1+2*3 => BinOp('+', Num(1), BinOp('*', Num(2), Num(3)))
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tree = p("1+2*3")
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self.assertEqual(tree, BinOp("+", Num(1), BinOp("*", Num(2), Num(3))))
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def test_div_binds_tighter_than_sub(self):
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# 9-6/2 => BinOp('-', Num(9), BinOp('/', Num(6), Num(2)))
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tree = p("9-6/2")
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self.assertEqual(tree, BinOp("-", Num(9), BinOp("/", Num(6), Num(2))))
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def test_add_before_mul_different_shape(self):
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# 1+2*3 must NOT parse as (1+2)*3
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tree = p("1+2*3")
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self.assertNotEqual(tree, BinOp("*", BinOp("+", Num(1), Num(2)), Num(3)))
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class TestD2LeftAssociativity(unittest.TestCase):
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def test_sub_left_assoc(self):
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# 8-3-2 => BinOp('-', BinOp('-', Num(8), Num(3)), Num(2))
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tree = p("8-3-2")
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self.assertEqual(tree, BinOp("-", BinOp("-", Num(8), Num(3)), Num(2)))
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def test_div_left_assoc(self):
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# 8/4/2 => BinOp('/', BinOp('/', Num(8), Num(4)), Num(2))
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tree = p("8/4/2")
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self.assertEqual(tree, BinOp("/", BinOp("/", Num(8), Num(4)), Num(2)))
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def test_add_left_assoc(self):
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# 1+2+3 => BinOp('+', BinOp('+', Num(1), Num(2)), Num(3))
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tree = p("1+2+3")
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self.assertEqual(tree, BinOp("+", BinOp("+", Num(1), Num(2)), Num(3)))
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def test_mul_left_assoc(self):
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# 2*3*4 => BinOp('*', BinOp('*', Num(2), Num(3)), Num(4))
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tree = p("2*3*4")
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self.assertEqual(tree, BinOp("*", BinOp("*", Num(2), Num(3)), Num(4)))
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class TestD3Parentheses(unittest.TestCase):
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def test_parens_override_precedence(self):
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# (1+2)*3 => BinOp('*', BinOp('+', Num(1), Num(2)), Num(3))
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tree = p("(1+2)*3")
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self.assertEqual(tree, BinOp("*", BinOp("+", Num(1), Num(2)), Num(3)))
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def test_nested_parens(self):
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# ((2+3)) => BinOp('+', Num(2), Num(3)) (extra parens transparent)
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tree = p("((2+3))")
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self.assertEqual(tree, BinOp("+", Num(2), Num(3)))
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def test_parens_and_precedence_mixed(self):
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# 2*(3+4*5) => BinOp('*', Num(2), BinOp('+', Num(3), BinOp('*', Num(4), Num(5))))
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tree = p("2*(3+4*5)")
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self.assertEqual(
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tree,
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BinOp("*", Num(2), BinOp("+", Num(3), BinOp("*", Num(4), Num(5)))),
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)
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class TestD4UnaryMinus(unittest.TestCase):
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def test_leading_unary(self):
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# -5 => Unary('-', Num(5))
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tree = p("-5")
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self.assertEqual(tree, Unary("-", Num(5)))
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def test_unary_in_parens(self):
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# -(1+2) => Unary('-', BinOp('+', Num(1), Num(2)))
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tree = p("-(1+2)")
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self.assertEqual(tree, Unary("-", BinOp("+", Num(1), Num(2))))
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def test_unary_after_binop(self):
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# 3 * -2 => BinOp('*', Num(3), Unary('-', Num(2)))
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tree = p("3 * -2")
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self.assertEqual(tree, BinOp("*", Num(3), Unary("-", Num(2))))
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def test_double_unary(self):
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# --5 => Unary('-', Unary('-', Num(5)))
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tree = p("--5")
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self.assertEqual(tree, Unary("-", Unary("-", Num(5))))
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class TestD5Errors(unittest.TestCase):
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def _raises(self, src: str):
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with self.assertRaises(ParseError, msg=f"expected ParseError for {src!r}"):
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p(src)
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def test_trailing_operator(self):
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self._raises("1 +")
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def test_unclosed_paren(self):
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self._raises("(1")
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def test_two_numbers_no_op(self):
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self._raises("1 2")
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def test_close_before_open(self):
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self._raises(")(")
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def test_empty_string(self):
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self._raises("")
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def test_open_close_no_expr(self):
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# "()" should fail — no expression inside
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self._raises("()")
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if __name__ == "__main__":
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unittest.main()
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