fix: ignore .woff2 and modern static-asset extensions - #4
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marcin-prerender merged 1 commit intoJun 12, 2026
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The EXTENSIONS_TO_IGNORE list predates woff2 and other modern asset formats. Matching is case-insensitive suffix matching, so ".woff" does not cover ".woff2" — bot requests for woff2 fonts were forwarded to the Prerender service instead of passing through to the servlet chain. Aligns with the integration contract (CONTRACT.md §3): adds .woff2, .otf, .eot, .webp, .avif, .webmanifest. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
OpsBeaconCharles
approved these changes
Jun 12, 2026
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The bug
EXTENSIONS_TO_IGNORE in PrerenderConfig.java predates woff2 and other modern asset formats. The filter uses case-insensitive suffix matching (toLowerCase + endsWith), so .woff does not cover .woff2 — bot requests for .woff2 fonts (and .otf, .eot, .webp, .avif, .webmanifest assets) are forwarded to the Prerender service instead of passing through to the servlet chain.
Live evidence
Verified against prerender.io itself: Googlebot requesting prerender.io's own inter-*.woff2 font gets a 504 (the same request with a normal browser UA returns 200), while .css/.js requests correctly bypass the integration. Static assets should never be sent to the render service.
Coordinated propagation
This change propagates the canonical update to the integration contract's static-asset ignore list (CONTRACT.md §3): prerender/integration-contract#1. The same fix is being applied across the official integration repos.
Changes
Behavior change
Bot requests for the six new extensions are no longer prerendered — they pass through to the normal servlet chain. If anyone relied on prerendering URLs ending in these suffixes (unlikely; they are binary/static formats), that behavior changes.
Tests
mvn test: 13/13 passing locally (including the contract suite against mock-server.mjs).
🤖 Generated with Claude Code