| name | bump-size-limit |
| description | Bump size limits in .size-limit.js when the size-limit CI check is failing. Use when the user mentions size limit failures, bundle size checks failing, CI size check errors, or needs to update size-limit thresholds. Also use when the user says "bumpSizeLimit", "fix size limit", "size check failing", or "update bundle size limits". |
Bump Size Limit
When the size-limit GitHub Action fails, it means one or more bundle scenarios exceed their configured byte thresholds in .size-limit.js. This skill walks through building, measuring, and bumping only the limits that need it.
Workflow
Step 1: Build all packages (including CDN bundles)
A full build is required because size-limit measures the actual compiled artifacts.
yarn build
This takes a few minutes. CDN bundles in packages/browser/build/bundles/ must be up to date — a dev build is not sufficient.
Step 2: Run the size check in JSON mode
yarn test:size-limit
The JSON output is an array of objects. Each object has:
name — the scenario labelpassed — whether it's within the limitsize — actual size in bytessizeLimit — configured limit in bytes
Step 3: Identify failed scenarios
Filter for entries where "passed": false. These are the only ones that need bumping.
Step 4: Calculate new limits
For each failed scenario, round the actual size up to the next full KB (1 KB = 1000 bytes in this context, matching how size-limit interprets the limits in .size-limit.js).
Example: If actual size is 129,127 bytes, the new limit is 130 KB (i.e. 130,000 bytes).
The heuristic is intentionally conservative — it gives just enough headroom without inflating limits unnecessarily.
Step 5: Update .size-limit.js
Open .size-limit.js at the repository root and update the limit field for each failed scenario. Limits are strings like '130 KB'.
Only change limits for scenarios that actually failed. Do not touch passing scenarios.
Step 6: Verify the fix
Re-run size-limit to confirm everything passes:
yarn test:size-limit
If any scenario still fails (e.g., due to rounding edge cases), bump that specific limit by another 1 KB and re-run.
