[thaumaturgy]

I had a similar-ish problem just last night. Spent over an hour crawling through some code trying to figure out why it wasn't working like it was supposed to. I ended up doing the divide-and-conquer approach with "console debugging". I was cursing wildly by the end of it.

All to find in the end that I had used ( ) instead of [ ] (or maybe it was the other way 'round?) in a thick spot of code, and Javascript was happy to try to do that without throwing any kind of error.

That sort of thing happens in all languages to some extent, but debugging in Javascript is unmitigated hell.