1 files changed, 148 insertions, 0 deletions
diff --git a/Lib/test/test_strlit.py b/Lib/test/test_strlit.py
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+++ b/Lib/test/test_strlit.py
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+r"""Test correct treatment of various string literals by the parser.
+
+There are four types of string literals:
+
+    'abc'   -- normal str
+    r'abc'  -- raw str
+    b'xyz'  -- normal bytes
+    br'xyz' -- raw bytes
+
+The difference between normal and raw strings is of course that in a
+raw string, \ escapes (while still used to determine the end of the
+literal) are not interpreted, so that r'\x00' contains four
+characters: a backslash, an x, and two zeros; while '\x00' contains a
+single character (code point zero).
+
+The tricky thing is what should happen when non-ASCII bytes are used
+inside literals.  For bytes literals, this is considered illegal.  But
+for str literals, those bytes are supposed to be decoded using the
+encoding declared for the file (UTF-8 by default).
+
+We have to test this with various file encodings.  We also test it with
+exec()/eval(), which uses a different code path.
+
+This file is really about correct treatment of encodings and
+backslashes.  It doens't concern itself with issues like single
+vs. double quotes or singly- vs. triply-quoted strings: that's dealt
+with elsewhere (I assume).
+"""
+
+import os
+import sys
+import shutil
+import tempfile
+import unittest
+
+
+TEMPLATE = r"""# coding: %s
+a = 'x'
+assert ord(a) == 120
+b = '\x01'
+assert ord(b) == 1
+c = r'\x01'
+assert list(map(ord, c)) == [92, 120, 48, 49]
+d = '\x81'
+assert ord(d) == 0x81
+e = r'\x81'
+assert list(map(ord, e)) == [92, 120, 56, 49]
+f = '\u1881'
+assert ord(f) == 0x1881
+g = r'\u1881'
+assert list(map(ord, g)) == [92, 117, 49, 56, 56, 49]
+"""
+
+
+def byte(i):
+    return bytes([i])
+
+
+class TestLiterals(unittest.TestCase):
+
+    def setUp(self):
+        self.save_path = sys.path[:]
+        self.tmpdir = tempfile.mkdtemp()
+        sys.path.insert(0, self.tmpdir)
+
+    def tearDown(self):
+        sys.path = self.save_path
+        shutil.rmtree(self.tmpdir, ignore_errors=True)
+
+    def test_template(self):
+        # Check that the template doesn't contain any non-printables
+        # except for \n.
+        for c in TEMPLATE:
+            assert c == '\n' or ' ' <= c <= '~', repr(c)
+
+    def test_eval_str_normal(self):
+        self.assertEqual(eval(""" 'x' """), 'x')
+        self.assertEqual(eval(r""" '\x01' """), chr(1))
+        self.assertEqual(eval(""" '\x01' """), chr(1))
+        self.assertEqual(eval(r""" '\x81' """), chr(0x81))
+        self.assertEqual(eval(""" '\x81' """), chr(0x81))
+        self.assertEqual(eval(r""" '\u1881' """), chr(0x1881))
+        self.assertEqual(eval(""" '\u1881' """), chr(0x1881))
+
+    def test_eval_str_raw(self):
+        self.assertEqual(eval(""" r'x' """), 'x')
+        self.assertEqual(eval(r""" r'\x01' """), '\\' + 'x01')
+        self.assertEqual(eval(""" r'\x01' """), chr(1))
+        self.assertEqual(eval(r""" r'\x81' """), '\\' + 'x81')
+        self.assertEqual(eval(""" r'\x81' """), chr(0x81))
+        self.assertEqual(eval(r""" r'\u1881' """), '\\' + 'u1881')
+        self.assertEqual(eval(""" r'\u1881' """), chr(0x1881))
+
+    def test_eval_bytes_normal(self):
+        self.assertEqual(eval(""" b'x' """), b'x')
+        self.assertEqual(eval(r""" b'\x01' """), byte(1))
+        self.assertEqual(eval(""" b'\x01' """), byte(1))
+        self.assertEqual(eval(r""" b'\x81' """), byte(0x81))
+        self.assertRaises(SyntaxError, eval, """ b'\x81' """)
+        self.assertEqual(eval(r""" b'\u1881' """), b'\\' + b'u1881')
+        self.assertRaises(SyntaxError, eval, """ b'\u1881' """)
+
+    def test_eval_bytes_raw(self):
+        self.assertEqual(eval(""" br'x' """), b'x')
+        self.assertEqual(eval(r""" br'\x01' """), b'\\' + b'x01')
+        self.assertEqual(eval(""" br'\x01' """), byte(1))
+        self.assertEqual(eval(r""" br'\x81' """), b"\\" + b"x81")
+        self.assertRaises(SyntaxError, eval, """ br'\x81' """)
+        self.assertEqual(eval(r""" br'\u1881' """), b"\\" + b"u1881")
+        self.assertRaises(SyntaxError, eval, """ br'\u1881' """)
+
+    def check_encoding(self, encoding, extra=""):
+        modname = "xx_" + encoding.replace("-", "_")
+        fn = os.path.join(self.tmpdir, modname + ".py")
+        f = open(fn, "w", encoding=encoding)
+        try:
+            f.write(TEMPLATE % encoding)
+            f.write(extra)
+        finally:
+            f.close()
+        __import__(modname)
+        del sys.modules[modname]
+
+    def test_file_utf_8(self):
+        extra = "z = '\u1234'; assert ord(z) == 0x1234\n"
+        self.check_encoding("utf-8", extra)
+
+    def test_file_utf_8_error(self):
+        extra = "b'\x80'\n"
+        self.assertRaises(SyntaxError, self.check_encoding, "utf-8", extra)
+
+    def test_file_utf8(self):
+        self.check_encoding("utf8")
+
+    def test_file_iso_8859_1(self):
+        self.check_encoding("iso-8859-1")
+
+    def test_file_latin_1(self):
+        self.check_encoding("latin-1")
+
+    def test_file_latin9(self):
+        self.check_encoding("latin9")
+
+
+if __name__ == "__main__":
+    # Hack so that error messages containing non-ASCII can be printed
+    sys.stdout._encoding = sys.stderr._encoding = "utf-8"
+    unittest.main()