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Web-compatible header value parsers

Hastily made by @annevk

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Goals

  • Clients agree on parsing, including on erroneous input
  • Parsing is robust in the face of naïvely-combining intermediaries

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Revised parsers

  • Obtain the combined value
  • Parse that

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Contrived example

  • Content-Type: text/html; charset=”�Content-Type: egal”
  • Parser operates on text/html; charset=“, egal”

​

(Please excuse the incorrect quotes.)

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Investigation is ongoing

  • Mostly complete
    • Content-Length
    • Content-Type
    • X-Content-Type-Options
    • Various CORS headers
  • Tracking issue: https://github.com/whatwg/fetch/issues/814

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Tests

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Would love your help

  • Many thanks to Matt Menke
  • GitHub
    • whatwg/fetch
    • web-platform-tests/wpt