assign tag syntax errors

[jg-rp]

The {% assign %} tag does not currently catch Liquid syntax errors from trailing garbage, after a valid filtered expression. In this example, the erroneous offset: 2 is silently ignored.

{% assign foo = 'bar' offset:2 %}

In other words, we don't check for EOF after parsing the left hand side of the assignment expression.

liquid/liquid/builtin/tags/assign_tag.py

Lines 78 to 90 in 3656c74

	match = RE_ASSIGNMENT.match(stream.current.value)
	if match:
	name, expression = match.groups()
	else:
	raise LiquidSyntaxError(
	f'invalid assignment expression "{stream.current.value}"',
	linenum=stream.current.linenum,
	)
	return AssignNode(
	tok,
	AssignmentExpression(name, self._parse_expression(expression)),
	)