[DEV] Escapable curly braces (#955)

docs/source/config_reference/scripting/scripting_types.rst

@@ -88,6 +88,12 @@ triple-quotes can be used to avoid *closing* the String.
  %string("""This has both " and ' in it.""")
  }
 
+If you want a plain string that contains literal curly braces, you can escape them like so:
+
+.. code-block:: yaml
+
+ string_variable: "This contains \\{ literal curly braces \\}"
+
 Integer
 ~~~~~~~
 

src/ytdl_sub/script/parser.py

@@ -73,6 +73,8 @@ class ParsedArgType(Enum):
 
 FUNCTION_INVALID_CHAR = InvalidSyntaxException("Invalid value when parsing a function")
 
+BRACKET_INVALID_CHAR = InvalidSyntaxException("Invalid value within brackets")
+
 
 def _UNEXPECTED_CHAR_ARGUMENT(arg_type: ParsedArgType):
  return InvalidSyntaxException(f"Unexpected character when parsing {arg_type.value} arguments")
@@ -505,6 +507,10 @@ def _parse_map(self) -> UnresolvedMap:
  raise UNREACHABLE
 
  def _parse_main_loop(self, ch: str) -> bool:
+ if ch == "\\" and self._read(increment_pos=False) in {"{", "}"}:
+ # Escape brackets are \{ and \}, only add the second char
+ self._literal_str += self._read()
+ return True
  if ch == "}":
  if self._bracket_counter == 0:
  raise BRACKET_NOT_CLOSED
@@ -558,9 +564,9 @@ def _parse_main_loop(self, ch: str) -> bool:
  elif self._bracket_counter == 0:
  # Only accumulate literal str if not in brackets
  self._literal_str += ch
- else:
- # Should only be possible to get here if it's a space
- assert ch.isspace()
+ elif not ch.isspace():
+ self._set_highlight_position(pos=self._pos - 1)
+ raise BRACKET_INVALID_CHAR
 
  return True
 

tests/unit/script/test_parser.py

@@ -5,6 +5,7 @@
 import pytest
 
 from ytdl_sub.script.parser import _UNEXPECTED_CHAR_ARGUMENT
+from ytdl_sub.script.parser import BRACKET_INVALID_CHAR
 from ytdl_sub.script.parser import BRACKET_NOT_CLOSED
 from ytdl_sub.script.parser import ParsedArgType
 from ytdl_sub.script.parser import parse
@@ -192,6 +193,15 @@ def test_lambda_function(self):
  ]
  )
 
+ def test_escaped_bracket(self):
+ assert parse("\\{ This is escape {%string('{}')} and here \\}") == SyntaxTree(
+ [
+ String(value="{ This is escape "),
+ BuiltInFunction(name="string", args=[String(value="{}")]),
+ String(value=" and here }"),
+ ]
+ )
+
 
 class TestParserBracketFailures:
  def test_bracket_open(self):
@@ -208,3 +218,8 @@ def test_bracket_in_function(self):
  match=re.escape(str(_UNEXPECTED_CHAR_ARGUMENT(ParsedArgType.MAP_KEY))),
  ):
  parse("hello {%capitalize({as_arg)}")
+
+ @pytest.mark.parametrize("char", [")", ",", "*", "]"])
+ def test_extra_char_in_brackets(self, char: str):
+ with pytest.raises(InvalidSyntaxException, match=re.escape(str(BRACKET_INVALID_CHAR))):
+ parse(f"{{ %string('hi') {char} }}")