Custom opstring parsing when multiple instances of same flag is applied? - node.js

Question

I have a command line program where I want to generate a picture given multiple arguments, where the order of the arguments should be respected, and duplicate arguments are allowed
Are there any node.js optstring parsers that would allow for this?
I would like to have something like
generate_picture --red 100 --yellow 200 --red 100 --width 500
And then it generates a "flag" with a red 100px band on top, then a 200px band of yellow, and then another 100px red band, all applied with width 500px
My program doesn't literally do that but it is similar
I think the ideal form that my program would receive these arguments would be an array of arrays like this
[
['red', 100],
['yellow', 200],
['red', 100],
['width', 500]
]
I would probably up-front scan this array-of-arrays for the things i expect to only be applied once like width
I suppose now that I write it out, it might not be too hard to manually parse the process.argv array to get it into this state but curious if there are any options available already

Answer 1

To help my particular circumstance I made this utility function
function parseArgv(argv) {
const map = [];
while (argv.length) {
const val = argv[0].slice(2);
argv = argv.slice(1);
const next = argv.findIndex((arg) => arg.startsWith("-"));
if (next !== -1) {
map.push([val, argv.slice(0, next)]);
argv = argv.slice(next);
} else {
map.push([val, argv]);
break;
}
}
return map;
}
Example usage
test("parse", () => {
expect(
parseArgv(
"--bam file1.bam color:red --vcf variants.vcf --bam file2.bam --defaultSession --out out.svg --fullSvg".split(
" "
)
)
).toEqual([
["bam", ["file1.bam", "color:red"]],
["vcf", ["variants.vcf"]],
["bam", ["file2.bam"]],
["defaultSession", []],
["out", ["out.svg"]],
["fullSvg", []],
]);
});
Then post processing can make a little more sense of this, but this utility function was helpful for my purposes in a way that was not achievable with yargs or other node optstring parsers