commands: only accept escaped quotes

instead of accepting quotation marks in strings, we now just accept \x22,
which is then unescaped by the str type. This greatly simplifies
the lexing and is more consistent from a user perspective.

mitmproxy/command_lexer.py

@@ -9,13 +9,9 @@ import pyparsing
 PartialQuotedString = pyparsing.Regex(
     re.compile(
         r'''
-            (["'])  # start quote
-            (?:
-                (?:\\.)  # escape sequence
-                |
-                (?!\1).  # unescaped character that is not our quote nor the begin of an escape sequence. We can't use \1 in []
-            )*
-            (?:\1|$)  # end quote
+            "[^"]*(?:"|$)  # double-quoted string that ends with double quote or EOF
+            |
+            '[^']*(?:'|$)  # single-quoted string that ends with double quote or EOF
         ''',
         re.VERBOSE
     )
@@ -35,17 +31,11 @@ def quote(val: str) -> str:
         return f'"{val}"'
     if "'" not in val:
         return f"'{val}'"
-    return '"' + re.sub(r'(?<!\\)(\\\\)*"', lambda m: (m.group(1) or "") + '\\"', val) + '"'
+    return '"' + val.replace('"', r"\x22") + '"'
 
 
 def unquote(x: str) -> str:
-    quote_char = ""
-    if len(x) > 1 and x.startswith('"') and x.endswith('"'):
-        quote_char = '"'
-    if len(x) > 1 and x.startswith("'") and x.endswith("'"):
-        quote_char = "'"
-
-    if quote_char:
-        return re.sub(r"(?<!\\)(\\\\)*\\" + quote_char, lambda m: (m.group(1) or "") + quote_char, x[1:-1])
+    if len(x) > 1 and x[0] in "'\"" and x[0] == x[-1]:
+        return x[1:-1]
     else:
         return x

mitmproxy/types.py

@@ -119,7 +119,7 @@ class _StrType(_BaseType):
         """, re.VERBOSE)
 
     @staticmethod
-    def _unescape(match: re.Match[str]) -> str:
+    def _unescape(match: re.Match) -> str:
         return codecs.decode(match.group(0), "unicode-escape")  # type: ignore
 
     def completion(self, manager: "CommandManager", t: type, s: str) -> typing.Sequence[str]:

test/mitmproxy/test_command.py

@@ -367,24 +367,6 @@ class TestCommand:
                 ],
                 [],
             ],
-            [
-                r'cmd13 "a \"b\" c"',
-                [
-                    command.ParseResult(value="cmd13", type=mitmproxy.types.Cmd, valid=False),
-                    command.ParseResult(value=" ", type=mitmproxy.types.Space, valid=True),
-                    command.ParseResult(value=r'"a \"b\" c"', type=mitmproxy.types.Unknown, valid=False),
-                ],
-                [],
-            ],
-            [
-                r"cmd14 'a \'b\' c'",
-                [
-                    command.ParseResult(value="cmd14", type=mitmproxy.types.Cmd, valid=False),
-                    command.ParseResult(value=" ", type=mitmproxy.types.Space, valid=True),
-                    command.ParseResult(value=r"'a \'b\' c'", type=mitmproxy.types.Unknown, valid=False),
-                ],
-                [],
-            ],
             [
                 "    spaces_at_the_begining_are_not_stripped",
                 [
@@ -436,12 +418,6 @@ def test_simple():
             c.call("nonexistent")
         with pytest.raises(exceptions.CommandError, match="Unknown"):
             c.execute("\\")
-        with pytest.raises(exceptions.CommandError, match="Unknown"):
-            c.execute(r"\'")
-        with pytest.raises(exceptions.CommandError, match="Unknown"):
-            c.execute(r"\"")
-        with pytest.raises(exceptions.CommandError, match="Unknown"):
-            c.execute(r"\"")
 
         c.add("empty", a.empty)
         c.execute("empty")

test/mitmproxy/test_command_lexer.py

@@ -11,7 +11,6 @@ from mitmproxy import command_lexer
         ("'foo'", True),
         ('"foo"', True),
         ("'foo' bar'", False),
-        ("'foo\\' bar'", True),
         ("'foo' 'bar'", False),
         ("'foo'x", False),
         ('''"foo    ''', True),
@@ -52,8 +51,10 @@ def test_expr(test_input, expected):
 @example("'foo\\\\'")
 @example("\"foo\\'\"")
 @example("\"foo\\\\'\"")
+@example('\'foo\\"\'')
+@example(r"\\\foo")
 def test_quote_unquote_cycle(s):
-    assert command_lexer.unquote(command_lexer.quote(s)) == s
+    assert command_lexer.unquote(command_lexer.quote(s)).replace(r"\x22", '"') == s
 
 
 @given(text())

test/mitmproxy/test_websocket.py

@@ -34,7 +34,7 @@ class TestWebSocketMessage:
         bin = websocket.WebSocketMessage(Opcode.BINARY, True, b"foo")
 
         assert txt.is_text
-        assert txt.text
+        assert txt.text == "foo"
         txt.text = "bar"
         assert txt.content == b"bar"
 

test/mitmproxy/tools/console/test_defaultkeys.py

@@ -20,18 +20,18 @@ async def test_commands_exist():
     await m.load_flow(tflow())
 
     for binding in km.bindings:
-        parsed, _ = command_manager.parse_partial(binding.command.strip())
-
-        cmd = parsed[0].value
-        args = [
-            a.value for a in parsed[1:]
-            if a.type != mitmproxy.types.Space
-        ]
-
-        assert cmd in m.commands.commands
-
-        cmd_obj = m.commands.commands[cmd]
         try:
+            parsed, _ = command_manager.parse_partial(binding.command.strip())
+
+            cmd = parsed[0].value
+            args = [
+                a.value for a in parsed[1:]
+                if a.type != mitmproxy.types.Space
+            ]
+
+            assert cmd in m.commands.commands
+
+            cmd_obj = m.commands.commands[cmd]
             cmd_obj.prepare_args(args)
         except Exception as e:
-            raise ValueError(f"Invalid command: {binding.command}") from e
+            raise ValueError(f"Invalid binding: {binding.command}") from e