CLAUDE WATERMARK REMOVER · MARKDOWN TEST
Can a hidden character activate a bare Markdown reference link after cleanup?
Removing U+200B from the shortcut label made it match the existing definition and turned the bracketed text into a link.
What changed in the preview
A shortcut reference has one bracket pair and no destination beside it. Search for definitions elsewhere in the document before changing a bracketed label. If you intend literal brackets even when a definition exists, escape the opening bracket.
What this test covers
The definition stays identical. This test measures a Markdown lookup without requesting the resulting URL. Compare the two rendered outputs below with the original and cleaned source.
Measured source and preview
Original Markdown
See [dr\u200Baft]. [draft]: /draft
Cleaned Markdown
See [draft]. [draft]: /draft
The original source and its preview contain a literal U+200B, displayed below as \u200B. The HTML is shown as text.
Before cleanup
<p>See [dr\u200Baft].</p>
After cleanup
<p>See <a href="/draft">draft</a>.</p>
Reproduce locally
Save reproduce.cjs and tested-app.js together. Run npm install --no-save commonmark@0.31.2, then node reproduce.cjs. Compare with the recorded input, output and HTML. The test uses the homepage callback with a minimal DOM. It does not use Claude output or test statistical watermark detection.
See the CommonMark specification and another measured Markdown case.