fix(lambda-edge): classify ZIP-based document subtypes as binary#4900
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rokasta12 wants to merge 1 commit into
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fix(lambda-edge): classify ZIP-based document subtypes as binary#4900rokasta12 wants to merge 1 commit into
rokasta12 wants to merge 1 commit into
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The previous regex `application/(.*json|.*xml).*` matched any subtype containing the substrings "json" or "xml" anywhere, including `application/vnd.openxmlformats-officedocument.*` (.docx/.xlsx/.pptx), `application/epub+zip`, and `application/vnd.oasis.opendocument.*`. These are ZIP archives. Treating them as text caused the body to be returned un-base64-encoded, so CloudFront delivered corrupted files to clients. Replaces the regex with the boundary-aware pattern already used by the aws-lambda adapter: it accepts `text/(plain|html|css|javascript|csv)` at the start, or `/json`, `/xml`, `+json`, `+xml` followed by `;` or end-of-string. This keeps `application/atom+xml`, `application/ld+json`, and `image/svg+xml` as text while correctly rejecting OOXML/EPUB/ODT.
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Problem
isContentTypeBinaryinsrc/adapter/lambda-edge/handler.tsused the regexapplication/(.*json|.*xml).*, which matches any subtype that contains the substringjsonorxmlanywhere — including ZIP archives whose subtypes happen to embed those letters:application/vnd.openxmlformats-officedocument.wordprocessingml.document(.docx)application/vnd.openxmlformats-officedocument.spreadsheetml.sheet(.xlsx)application/vnd.openxmlformats-officedocument.presentationml.presentation(.pptx)application/epub+zip(.epub)application/vnd.oasis.opendocument.text(.odt)When
isContentTypeBinaryreturnsfalse, the response body is returned to CloudFront un-base64-encoded, so any user serving these document types from a Lambda@Edge handler delivers a corrupted file.Fix
Replace the regex with the boundary-aware pattern already used by the aws-lambda adapter (
src/adapter/aws-lambda/handler.ts:675):This accepts:
text/(plain|html|css|javascript|csv)at the start/json,/xml,+json,+xmlfollowed by;or end-of-stringSo
application/atom+xml,application/ld+json, andimage/svg+xmlcontinue to be treated as text, while OOXML/EPUB/ODT subtypes are correctly classified as binary.Test
Added a regression test covering the OOXML triple,
application/epub+zip, andapplication/vnd.oasis.opendocument.textalongside the existing assertions. The new test fails onmainand passes with the regex fix.bun run test— passes)bun run format:fix && bun run lint:fix