Problem processing the following html

[nexon33]

When I calculate the diff using the following code snippets I run into some trouble, for some reason multiline strings are not handled accordingly. I first calculate the diff and then apply the diff on an empty div.

when I use

<div data-interchange="[/some/link, (default)],
                                [/some/other/link, (medium)]">
</div>

I get the error

DOMException: Failed to execute 'setAttribute' on 'Element': '(default)],' is not a valid attribute name. and when I use

<div data-interchange="
        [/some/link, (default)],
                                [/some/other/link, (medium)]">
</div>

I get

DOMException: Failed to execute 'setAttribute' on 'Element': '[' is not a valid attribute name.

but when I use

<div data-interchange="[/some/link, (default)], [/some/other/link, (medium)]">
</div>

then I get no error.