1"""Tests for the asdl parser in Parser/asdl.py"""
2
3import importlib.machinery
4import importlib.util
5import os
6from os.path import dirname
7import sys
8import sysconfig
9import unittest
10
11
12# This test is only relevant for from-source builds of Python.
13if not sysconfig.is_python_build():
14    raise unittest.SkipTest('test irrelevant for an installed Python')
15
16src_base = dirname(dirname(dirname(__file__)))
17parser_dir = os.path.join(src_base, 'Parser')
18
19
20class TestAsdlParser(unittest.TestCase):
21    @classmethod
22    def setUpClass(cls):
23        # Loads the asdl module dynamically, since it's not in a real importable
24        # package.
25        # Parses Python.asdl into an ast.Module and run the check on it.
26        # There's no need to do this for each test method, hence setUpClass.
27        sys.path.insert(0, parser_dir)
28        loader = importlib.machinery.SourceFileLoader(
29                'asdl', os.path.join(parser_dir, 'asdl.py'))
30        spec = importlib.util.spec_from_loader('asdl', loader)
31        module = importlib.util.module_from_spec(spec)
32        loader.exec_module(module)
33        cls.asdl = module
34        cls.mod = cls.asdl.parse(os.path.join(parser_dir, 'Python.asdl'))
35        cls.assertTrue(cls.asdl.check(cls.mod), 'Module validation failed')
36
37    @classmethod
38    def tearDownClass(cls):
39        del sys.path[0]
40
41    def setUp(self):
42        # alias stuff from the class, for convenience
43        self.asdl = TestAsdlParser.asdl
44        self.mod = TestAsdlParser.mod
45        self.types = self.mod.types
46
47    def test_module(self):
48        self.assertEqual(self.mod.name, 'Python')
49        self.assertIn('stmt', self.types)
50        self.assertIn('expr', self.types)
51        self.assertIn('mod', self.types)
52
53    def test_definitions(self):
54        defs = self.mod.dfns
55        self.assertIsInstance(defs[0], self.asdl.Type)
56        self.assertIsInstance(defs[0].value, self.asdl.Sum)
57
58        self.assertIsInstance(self.types['withitem'], self.asdl.Product)
59        self.assertIsInstance(self.types['alias'], self.asdl.Product)
60
61    def test_product(self):
62        alias = self.types['alias']
63        self.assertEqual(
64            str(alias),
65            'Product([Field(identifier, name), Field(identifier, asname, opt=True)], '
66            '[Field(int, lineno), Field(int, col_offset), '
67            'Field(int, end_lineno, opt=True), Field(int, end_col_offset, opt=True)])')
68
69    def test_attributes(self):
70        stmt = self.types['stmt']
71        self.assertEqual(len(stmt.attributes), 4)
72        self.assertEqual(repr(stmt.attributes[0]), 'Field(int, lineno)')
73        self.assertEqual(repr(stmt.attributes[1]), 'Field(int, col_offset)')
74        self.assertEqual(repr(stmt.attributes[2]), 'Field(int, end_lineno, opt=True)')
75        self.assertEqual(repr(stmt.attributes[3]), 'Field(int, end_col_offset, opt=True)')
76
77    def test_constructor_fields(self):
78        ehandler = self.types['excepthandler']
79        self.assertEqual(len(ehandler.types), 1)
80        self.assertEqual(len(ehandler.attributes), 4)
81
82        cons = ehandler.types[0]
83        self.assertIsInstance(cons, self.asdl.Constructor)
84        self.assertEqual(len(cons.fields), 3)
85
86        f0 = cons.fields[0]
87        self.assertEqual(f0.type, 'expr')
88        self.assertEqual(f0.name, 'type')
89        self.assertTrue(f0.opt)
90
91        f1 = cons.fields[1]
92        self.assertEqual(f1.type, 'identifier')
93        self.assertEqual(f1.name, 'name')
94        self.assertTrue(f1.opt)
95
96        f2 = cons.fields[2]
97        self.assertEqual(f2.type, 'stmt')
98        self.assertEqual(f2.name, 'body')
99        self.assertFalse(f2.opt)
100        self.assertTrue(f2.seq)
101
102    def test_visitor(self):
103        class CustomVisitor(self.asdl.VisitorBase):
104            def __init__(self):
105                super().__init__()
106                self.names_with_seq = []
107
108            def visitModule(self, mod):
109                for dfn in mod.dfns:
110                    self.visit(dfn)
111
112            def visitType(self, type):
113                self.visit(type.value)
114
115            def visitSum(self, sum):
116                for t in sum.types:
117                    self.visit(t)
118
119            def visitConstructor(self, cons):
120                for f in cons.fields:
121                    if f.seq:
122                        self.names_with_seq.append(cons.name)
123
124        v = CustomVisitor()
125        v.visit(self.types['mod'])
126        self.assertEqual(v.names_with_seq,
127                         ['Module', 'Module', 'Interactive', 'FunctionType'])
128
129
130if __name__ == '__main__':
131    unittest.main()
132