"each of the two letters are not continuous", maybe this should be checked in test cases.

yes, it is alike but at least you can view the source code at first to determine the char set...
this site works terriblly on phone browser anyway.

I do not think there could be a good description on this kata except all the test cases shown or all possible chars declared.
Such code can run out with correct result only under certain condition, which means you should know all the conditions. Thanks to the console.log we can know hwat line comes and then hwat to fix, or we could only get mad.

Maybe it is the only trap of this kata! :D

Maybe a declaration on FONT is somewhat a good hint...you know printing and handwriting is not the same, even Gigi knows it.

Some tests for short string?
Such as empty , , a and bc?

Thanks.
Random Tests Added.

Feared timeout so that I did not use such i++ solution... actually it can pass... Gakkari.

It was set as

!Spaces will be ignored but special characters and numbers won't match the string and return false.

Then is @ a special character?

Sorry I can not get the point... do you mean isPrime could be replaced with some cleverer way?