domdiff has a simple test before removing a node from its parent. udomdiff doesn't check the existence of the property parentNode on a node before removing it from the DOM.

Is this behavior intentional or is it a bug?

Hi, I really like domdiff and found out about udomdiff recently.
I also saw that udomdiff is more performant and smaller but does not provide a compare function, like domdiff does.

So I replaced lines https://github.com/WebReflection/udomdiff/blob/master/index.js#L59,
https://github.com/WebReflection/udomdiff/blob/master/index.js#L63 and https://github.com/WebReflection/udomdiff/blob/master/index.js#L69 with the compare Function and run into Problems with insertBefore on line 49.

How would it be possible to add it again?

I wasn't sure if it's a bug but I put together a benchmark comparing some diffing algorithms out there (based on your test code, thank you!).

udomdiff has 199 operations on updating the 10th row compared to the ideal 100.

see https://github.com/luwes/js-diff-benchmark

Hey,

I've been testing out some diffing algos, curious to see which DOM operations they actually perform.

One of the libraries I tested was this one, and I've come across a case where it seems to do an unnecessary DOM operation.

Here's my test bench:

https://jsfiddle.net/mindplay/o4gbaqw0/

I've added console.log statements for every DOM operation - you can press the buttons to perform various array operations to change the sorting of the elements, and then watch the console output for the exact DOM operations resulting from the diff operation from one state to the next.

It looks good for all operations except "Rotate Up" - which basically means, "take the first item on the list and move it to the bottom", which should be doable with a single insertBefore.

Instead, the result is two operations - a seemingly unnecessary replaceChild operation, followed by the expected insertBefore operation. (The resulting DOM state is correct though.)

With devtools open, you can see two nodes are being affected:

It isn't explicitly stated in the README of either this project or the original domdiff, but presumably the point of diffing is to perform as few DOM operations as possible? Just figured I'd report my findings, in case you do consider this a subtle "bug". 🙂

This is really an awesome piece of code! Congrats!

I'm trying to incorporate it in sinuous/map.
I was wondering about a use case when an item is a document fragment.
I see it works nicely with arrays.

what do you recommend for handling fragments?
convert the list items to arrays first or use something like uwire?

thanks!