cpython/Lib/test/test_parser.py

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import parser
import test_support
import unittest
#
# First, we test that we can generate trees from valid source fragments,
# and that these valid trees are indeed allowed by the tree-loading side
# of the parser module.
#
class RoundtripLegalSyntaxTestCase(unittest.TestCase):
def roundtrip(self, f, s):
st1 = f(s)
t = st1.totuple()
try:
st2 = parser.sequence2ast(t)
except parser.ParserError:
self.fail("could not roundtrip %r" % s)
self.assertEquals(t, st2.totuple(),
"could not re-generate syntax tree")
def check_expr(self, s):
self.roundtrip(parser.expr, s)
def check_suite(self, s):
self.roundtrip(parser.suite, s)
def test_expressions(self):
self.check_expr("foo(1)")
self.check_expr("[1, 2, 3]")
self.check_expr("[x**3 for x in range(20)]")
self.check_expr("[x**3 for x in range(20) if x % 3]")
self.check_expr("foo(*args)")
self.check_expr("foo(*args, **kw)")
self.check_expr("foo(**kw)")
self.check_expr("foo(key=value)")
self.check_expr("foo(key=value, *args)")
self.check_expr("foo(key=value, *args, **kw)")
self.check_expr("foo(key=value, **kw)")
self.check_expr("foo(a, b, c, *args)")
self.check_expr("foo(a, b, c, *args, **kw)")
self.check_expr("foo(a, b, c, **kw)")
self.check_expr("foo + bar")
self.check_expr("lambda: 0")
self.check_expr("lambda x: 0")
self.check_expr("lambda *y: 0")
self.check_expr("lambda *y, **z: 0")
self.check_expr("lambda **z: 0")
self.check_expr("lambda x, y: 0")
self.check_expr("lambda foo=bar: 0")
self.check_expr("lambda foo=bar, spaz=nifty+spit: 0")
self.check_expr("lambda foo=bar, **z: 0")
self.check_expr("lambda foo=bar, blaz=blat+2, **z: 0")
self.check_expr("lambda foo=bar, blaz=blat+2, *y, **z: 0")
self.check_expr("lambda x, *y, **z: 0")
def test_print(self):
self.check_suite("print")
self.check_suite("print 1")
self.check_suite("print 1,")
self.check_suite("print >>fp")
self.check_suite("print >>fp, 1")
self.check_suite("print >>fp, 1,")
def test_simple_expression(self):
# expr_stmt
self.check_suite("a")
def test_simple_assignments(self):
self.check_suite("a = b")
self.check_suite("a = b = c = d = e")
def test_simple_augmented_assignments(self):
self.check_suite("a += b")
self.check_suite("a -= b")
self.check_suite("a *= b")
self.check_suite("a /= b")
self.check_suite("a %= b")
self.check_suite("a &= b")
self.check_suite("a |= b")
self.check_suite("a ^= b")
self.check_suite("a <<= b")
self.check_suite("a >>= b")
self.check_suite("a **= b")
def test_function_defs(self):
self.check_suite("def f(): pass")
self.check_suite("def f(*args): pass")
self.check_suite("def f(*args, **kw): pass")
self.check_suite("def f(**kw): pass")
self.check_suite("def f(foo=bar): pass")
self.check_suite("def f(foo=bar, *args): pass")
self.check_suite("def f(foo=bar, *args, **kw): pass")
self.check_suite("def f(foo=bar, **kw): pass")
self.check_suite("def f(a, b): pass")
self.check_suite("def f(a, b, *args): pass")
self.check_suite("def f(a, b, *args, **kw): pass")
self.check_suite("def f(a, b, **kw): pass")
self.check_suite("def f(a, b, foo=bar): pass")
self.check_suite("def f(a, b, foo=bar, *args): pass")
self.check_suite("def f(a, b, foo=bar, *args, **kw): pass")
self.check_suite("def f(a, b, foo=bar, **kw): pass")
def test_import_from_statement(self):
self.check_suite("from sys.path import *")
self.check_suite("from sys.path import dirname")
self.check_suite("from sys.path import dirname as my_dirname")
self.check_suite("from sys.path import dirname, basename")
self.check_suite(
"from sys.path import dirname as my_dirname, basename")
self.check_suite(
"from sys.path import dirname, basename as my_basename")
def test_basic_import_statement(self):
self.check_suite("import sys")
self.check_suite("import sys as system")
self.check_suite("import sys, math")
self.check_suite("import sys as system, math")
self.check_suite("import sys, math as my_math")
#
# Second, we take *invalid* trees and make sure we get ParserError
# rejections for them.
#
class IllegalSyntaxTestCase(unittest.TestCase):
def check_bad_tree(self, tree, label):
try:
parser.sequence2ast(tree)
except parser.ParserError:
pass
else:
self.fail("did not detect invalid tree for %r" % label)
def test_junk(self):
# not even remotely valid:
self.check_bad_tree((1, 2, 3), "<junk>")
def test_print_chevron_comma(self):
"Illegal input: print >>fp,"""
tree = \
(257,
(264,
(265,
(266,
(268,
(1, 'print'),
(35, '>>'),
(290,
(291,
(292,
(293,
(295,
(296,
(297,
(298, (299, (300, (301, (302, (303, (1, 'fp')))))))))))))),
(12, ','))),
(4, ''))),
(0, ''))
self.check_bad_tree(tree, "print >>fp,")
def test_a_comma_comma_c(self):
"""Illegal input: a,,c"""
tree = \
(258,
(311,
(290,
(291,
(292,
(293,
(295,
(296,
(297,
(298, (299, (300, (301, (302, (303, (1, 'a')))))))))))))),
(12, ','),
(12, ','),
(290,
(291,
(292,
(293,
(295,
(296,
(297,
(298, (299, (300, (301, (302, (303, (1, 'c'))))))))))))))),
(4, ''),
(0, ''))
self.check_bad_tree(tree, "a,,c")
def test_illegal_operator(self):
"""Illegal input: a $= b"""
tree = \
(257,
(264,
(265,
(266,
(267,
(312,
(291,
(292,
(293,
(294,
(296,
(297,
(298,
(299,
(300, (301, (302, (303, (304, (1, 'a'))))))))))))))),
(268, (37, '$=')),
(312,
(291,
(292,
(293,
(294,
(296,
(297,
(298,
(299,
(300, (301, (302, (303, (304, (1, 'b'))))))))))))))))),
(4, ''))),
(0, ''))
self.check_bad_tree(tree, "a $= b")
test_support.run_unittest(RoundtripLegalSyntaxTestCase)
test_support.run_unittest(IllegalSyntaxTestCase)