improve tests

Author: methane

Lib/test/test_dstring.py

@@ -1,37 +1,50 @@
 import unittest
 
+_dstring_prefixes = "d db df dt dr drb drf drt".split()
+_dstring_prefixes += [p.upper() for p in _dstring_prefixes]
 
 class DStringTestCase(unittest.TestCase):
     def assertAllRaise(self, exception_type, regex, error_strings):
         for str in error_strings:
             with self.subTest(str=str):
                 with self.assertRaisesRegex(exception_type, regex) as cm:
                     eval(str)
-                # print("Testing expression:", repr(str))
-                # print(repr(cm.exception))
-                # print(repr(cm.exception.text))
 
     def test_single_quote(self):
         exprs = [
-            "d'hello'",
-            'D"hello"',
-            "d'hello\\nworld'",
+            f"{p}'hello, world'" for p in _dstring_prefixes
+        ] + [
+            f'{p}"hello, world"' for p in _dstring_prefixes
         ]
         self.assertAllRaise(SyntaxError, "d-string must be triple-quoted", exprs)
 
     def test_empty_dstring(self):
         exprs = [
-            "d''''''",
-            'D""""""',
+            f"{p}''''''" for p in _dstring_prefixes
+        ] + [
+            f'{p}""""""' for p in _dstring_prefixes
         ]
         self.assertAllRaise(SyntaxError, "d-string must start with a newline", exprs)
 
     def test_simple_dstring(self):
-        self.assertEqual(eval('d"""\n  hello world\n  """'), "hello world\n")
-        self.assertEqual(eval('d"""\n  hello world\n """'), " hello world\n")
-        self.assertEqual(eval('d"""\n  hello world\n"""'), "  hello world\n")
-        self.assertEqual(eval('d"""\n  hello world\\\n """'), " hello world")
-        self.assertEqual(eval('dr"""\n  hello world\\\n """'), " hello world\\\n")
+        cases = [
+            ('{prefix}"""\n  hello world\n  """', "hello world\n"),
+            ('{prefix}"""\n  hello world\n """', " hello world\n"),
+            ('{prefix}"""\n  hello world\n"""', "  hello world\n"),
+            ('{prefix}"""\n  hello world\\\n """', " hello world"),
+            ('{prefix}"""\n  hello world\\\n """', " hello world\\\n"),
+        ]
+
+        for p in _dstring_prefixes:
+            bstring = 'b' in p.lower()
+            rstring = 'r' in p.lower()
+            for source, expected in cases:
+                source = source.format(prefix=p)
+                if rstring:
+                    expected = expected.replace('\\', '\\\\').replace('\n', '\\n')
+                if bstring:
+                    expected = expected.encode()
+                self.assertEqual(eval(source), expected)
 
 
 if __name__ == '__main__':

Parser/action_helpers.c

@@ -1481,6 +1481,13 @@ _get_resized_exprs(Parser *p, Token *a, asdl_expr_seq *raw_expressions, Token *b
     Py_ssize_t common_indent_len = 0;
 
     if (is_dedent) {
+        if (total_items == 0) {
+            RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
+                a,
+                "d-string must start with a newline"
+            );
+            return NULL;
+        }
         expr_ty first_item = asdl_seq_GET(raw_expressions, 0);
         if (first_item->kind != Constant_kind
                 || PyUnicode_ReadChar(first_item->v.Constant.value, 0) != '\n') {

Parser/lexer/lexer.c

@@ -1124,7 +1124,7 @@ tok_get_normal_mode(struct tok_state *tok, tokenizer_mode* current_tok, struct t
                 case 'd':
                 case 'D':
                     if (quote_size != 3) {
-                        return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "d-string must be a multiline string"));
+                        return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok, "d-string must be triple-quoted"));
                     }
                     break;
                 default: