test_asdl_parser.py
"""Tests for the asdl parser in Parser/asdl.py"""
import importlib.machinery
import os
from os.path import dirname
import sys
import sysconfig
import unittest
# This test is only relevant for from-source builds of Python.
if not sysconfig.is_python_build():
raise unittest.SkipTest('test irrelevant for an installed Python')
src_base = dirname(dirname(dirname(__file__)))
parser_dir = os.path.join(src_base, 'Parser')
class TestAsdlParser(unittest.TestCase):
@classmethod
def setUpClass(cls):
# Loads the asdl module dynamically, since it's not in a real importable
# package.
# Parses Python.asdl into an ast.Module and run the check on it.
# There's no need to do this for each test method, hence setUpClass.
sys.path.insert(0, parser_dir)
loader = importlib.machinery.SourceFileLoader(
'asdl', os.path.join(parser_dir, 'asdl.py'))
cls.asdl = loader.load_module()
cls.mod = cls.asdl.parse(os.path.join(parser_dir, 'Python.asdl'))
cls.assertTrue(cls.asdl.check(cls.mod), 'Module validation failed')
@classmethod
def tearDownClass(cls):
del sys.path[0]
def setUp(self):
# alias stuff from the class, for convenience
self.asdl = TestAsdlParser.asdl
self.mod = TestAsdlParser.mod
self.types = self.mod.types
def test_module(self):
self.assertEqual(self.mod.name, 'Python')
self.assertIn('stmt', self.types)
self.assertIn('expr', self.types)
self.assertIn('mod', self.types)
def test_definitions(self):
defs = self.mod.dfns
self.assertIsInstance(defs[0], self.asdl.Type)
self.assertIsInstance(defs[0].value, self.asdl.Sum)
self.assertIsInstance(self.types['withitem'], self.asdl.Product)
self.assertIsInstance(self.types['alias'], self.asdl.Product)
def test_product(self):
alias = self.types['alias']
self.assertEqual(
str(alias),
'Product([Field(identifier, name), Field(identifier, asname, opt=True)])')
def test_attributes(self):
stmt = self.types['stmt']
self.assertEqual(len(stmt.attributes), 2)
self.assertEqual(str(stmt.attributes[0]), 'Field(int, lineno)')
self.assertEqual(str(stmt.attributes[1]), 'Field(int, col_offset)')
def test_constructor_fields(self):
ehandler = self.types['excepthandler']
self.assertEqual(len(ehandler.types), 1)
self.assertEqual(len(ehandler.attributes), 2)
cons = ehandler.types[0]
self.assertIsInstance(cons, self.asdl.Constructor)
self.assertEqual(len(cons.fields), 3)
f0 = cons.fields[0]
self.assertEqual(f0.type, 'expr')
self.assertEqual(f0.name, 'type')
self.assertTrue(f0.opt)
f1 = cons.fields[1]
self.assertEqual(f1.type, 'identifier')
self.assertEqual(f1.name, 'name')
self.assertTrue(f1.opt)
f2 = cons.fields[2]
self.assertEqual(f2.type, 'stmt')
self.assertEqual(f2.name, 'body')
self.assertFalse(f2.opt)
self.assertTrue(f2.seq)
def test_visitor(self):
class CustomVisitor(self.asdl.VisitorBase):
def __init__(self):
super().__init__()
self.names_with_seq = []
def visitModule(self, mod):
for dfn in mod.dfns:
self.visit(dfn)
def visitType(self, type):
self.visit(type.value)
def visitSum(self, sum):
for t in sum.types:
self.visit(t)
def visitConstructor(self, cons):
for f in cons.fields:
if f.seq:
self.names_with_seq.append(cons.name)
v = CustomVisitor()
v.visit(self.types['mod'])
self.assertEqual(v.names_with_seq, ['Module', 'Interactive', 'Suite'])
if __name__ == '__main__':
unittest.main()