bed file format issue with trailing comma in exons list

[gaitat]

Regarding a bed file, there are cases where there is a trailing comma ',' at the end of the blockSizes and blockStarts.
This causes the following code in ucsc.js

    if (!(exonSizes.length === exonStarts.length && exonCount === exonSizes.length)) {
        return feature;
    }

to succeed ending prematurely the parsing of the exons.

If you think this is a valid issue, may I suggest changing

    const exonSizes = tokens[10].split(',');
    const exonStarts = tokens[11].split(',');

to

    const exonSizes = tokens[10].replace(/,$/, '').split(',');
    const exonStarts = tokens[11].replace(/,$/, '').split(',');

in order to eliminate the trailing comma ',' from the two lists.

[jrobinso]

Yes, thank you for the fix.