Seconding this; I wrote a short review talking about why I was disappointed with a book, which covers events throughout the book, and all spoilers near that cutoff line are perfectly visible. D:
In case this is helpful: it seems the text is stripped after a certain number of characters, and thus the </Spoiler> closing tag is lost. So then when it gets converted to HTML, the opening <span class="spoiler spoiler-hidden"> never gets generated.
That sounds like a good solution… alternately, if you can do the text stripping after the conversion to HTML has happened, the open <span class="spoiler spoiler-hidden"> tag should just be auto-closed by the browser… but that’s a really hacky way to do things, and your suggested solution is better, imo.
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