Green and Blind: When a Passing Check Means Nothing
I wrote a commit message that says SEO.tsx "sets documentElement.lang" and "emits hreflang links". I opened a Spanish post in the browser, looked at the document, and there it was: documentElement.lang === "es" , and three <link rel="alternate" hreflang> tags for es , en , and x-default . Right language, right pairs, right default. The commit message was accurate. The site was also serving <html…
In a React 19 SPA on Vercel, a commit message claimed that the SEO.tsx component sets the documentElement.lang and emits hreflang links. However, upon browsing the site and inspecting the document, it was found that the documentElement.lang was set to en and there were three link rel= alternate hreflang tags for es, en, and x-default.
This discrepancy was due to the prerender step, which only wrote the head element and did not touch the html tag. Additionally, the hreflang annotations were missing, leading to incorrect language attribution for Spanish posts. The issue was fixed on August 21 by updating prerender.mjs to set lang on the html element and emit alternates based on src/config/translations.json.
The same changes were made to read the translations file, ensuring accurate language and hreflang information. Meanwhile, another bug involving AdSense ads was discovered, where a timeout was causing ads to disappear, creating empty rectangles labeled "Advertisement." This was resolved by updating the state machine to only start the grace period after AdSense reports done and to continue observing for late verdicts.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
