Make PublicKeyCredentialRequestOptions.rpId a DOMString

[zacknewman]

Both PublicKeyCredentialRpEntity.id and PublicKeyCredentialRequestOptions.rpId represent the same thing (i.e., RP ID); however the former is modeled as a DOMString while the latter is modeled as a USVString. These should be the same type. Specifically PublicKeyCredentialRequestOptions.rpId should be a DOMString as well or PublicKeyCredentialRpEntity.id should be a USVString. Should be noted that PublicKeyCredentialRequestOptionsJSON.rpId is already a DOMString.

[emlun]

Thanks for pointing this out!

2024-05-15 WG call: Agreed we should change PublicKeyCredentialRpEntity.id to USVString. Strictly speaking this is a breaking change (changing a type bound in input (contravariant) position to be more restrictive), but in practice this shouldn't be able to break any applications since then those credentials wouldn't have worked in get() anyway.

@jschanck Seeing as Firefox is the browser that makes the most actual use of WebIDL - would changing PublicKeyCredentialRpEntity.id to USVString be a problem for Firefox?

[jschanck]

No, that wouldn't be a problem.

[zacknewman]

PublicKeyCredentialRequestOptionsJSON.rpId should also be changed to a USVString too.