Ask HN: Best way to turn plain text tab-indented list into JSON?

I have a list of unknown depth in plain text, where the levels are represented by tabs.

Something like this:

    item 1
        item 1.1
        item 1.2
    item 2
        item 2.1
        item 2.2
            item 2.2.1
            item 2.2.2
    item 3

What is the most efficient way to turn this into a JSON array (ideally in JavaScript)?

Of course, I could go line by line, have a currIndentation variable and create an array, but I'm wondering if there is a better way.