Empty tuple in conditionals raises error

[dideler]

if ():  # Should be false, but getting TypeError

[dideler]

This looks like it's caused by this line: https://github.com/differentmatt/filbert/blob/master/filbert.js#L1844

Filbert assumes if there's an opening (, then it's an expression wrapped in parentheses like if (foo() and bar()): and calls parseParenExpression(). But it could also be a tuple.

parseParenExpression() consumes the outer parentheses and returns the enclosed expression. https://github.com/differentmatt/filbert/blob/master/filbert.js#L1997-L2005

So a conditional like

if ():

becomes

if :

which is invalid.

This also means that the following code doesn't raise an error

t = ()
if t:

since it doesn't call parseParenExpression()

Also note that the following should raise an error but doesn't:

if (1, 2):
# becomes
if 1, 2:  # Should raise "SyntaxError: invalid syntax"