Workshop Journal · Page 2

Transforms that shrink their input silently drop content when the input breaks their assumptions — count what you meant to keep before and after

An HTML-to-text crawler strips script tags and loses coordinates, Douglas–Peucker simplification collapses a closed polygon to two points, and a gzip byte-comparison test fails only in CI. Reducing transforms return plausible results even when the input breaks their assumptions, so count what must be kept (field fill rate, point count, area, decompressed content) before and after the transform.

In a world split into cells, don’t decide by the cell’s center — decide by the extent its content occupies and its size on screen

Map marker clusters overlap so counts are unreadable, trees pop in right in front of the camera in a tile streaming game, and lines from a coarse grid stamp squares. A cell’s center is inside the cell, but its content crosses the boundary — decide whether to show, merge, or draw by the content’s actual extent and the cell’s on-screen size.

Don't confirm email by the sender's "success" — open the receiving inbox every time you change the mail path

SPF, DKIM and DMARC all pass and the ESP says Delivered, yet mail lands in Gmail spam; or activating a new AWS SES receipt rule set silently stops another domain's mail. Email failures announce nothing, so after every sending or receiving change, send real mail to every address and open the inbox.

Don't assume the value you pass is the value that arrives — where a value can carry a special meaning, check it on the receiving side

Bundled JS passed to String.replace turns $& into a replacement pattern, a toggle group's value="" comes back as an auto-generated id, and a Next.js export { revalidate } re-export is silently ignored. Libraries give some values special meanings and act on them without errors — log the value on the receiving side and pass it in a form that avoids the special meaning.

External data is not final when it arrives — know when each field settles, and set keys, monitors and decisions by it

GA4's last two days show (not set) / Unassigned, a public data API returns 0 rows after region codes change, an upsert key with a filled-later field piles up duplicates, a usage API reports 0 before billing. External values get filled in, change and settle later. Key only on fixed fields, monitor count changes not errors, and decide after numbers settle.

Select by the property you mean, not by its name — a broad pattern quietly catches things you never intended

A .gitignore *.png drops Next.js icon.png from commits, killing what lsof -i :3000 returns takes down your browser, 2>/dev/null hides vercel ls output from grep, and a GA4 ID in .env.production counts localhost and preview traffic. Rules keyed on names silently catch extra targets; key them on the property you mean and look at the selection before acting.