Various attributes of ScopedCredentialInfo should probably be [SameObject]

[bzbarsky]

I expect the value they return never changes, right?

[equalsJeffH]

perhaps -- tho, "never changes" relative to what? I guess I'm uncertain wrt all the implications of [SameObject].

[bzbarsky]

tho, "never changes" relative to what?

[SameObject] means that if the attribute getter or method thus annotated is invoked twice with the same "this" value, the return value will be the same, no matter what other script executes between the two invocations, whether the event loop spins between the two invocations, etc.

[selfissued]

This issue proposes specific semantic refinements affecting interop. Therefore, I believe we should decide this before the Implementer's Draft.

[AngeloKai]

The issue doesn't impact the actual behavior but rather just add description to categorize the behavior. I removed the implementation-priority flag because it doesn't impact our codebase.

[bzbarsky]

It would impact Gecko's codebase, fwiw.

[selfissued]

On the call, people agreed with doing this. The exact list of attributes affected needs to be specified.

[equalsJeffH]

@bzbarsky which attrs were you thinking are [SameObject] ?

[bzbarsky]

"all of them" in this case, no? I only see two in the spec at this point, and I expect they are both [SameObject], but I haven't read the currently updated spec carefully to check whether this is true.

[jyasskin]

Ok, this wasn't entirely fixed by the Credential Manager merge. The remaining attributes that should be [SameObject] are:

interface PublicKeyCredential : Credential {
    readonly attribute ArrayBuffer           rawId;
    readonly attribute AuthenticatorResponse response;
    readonly attribute AuthenticationExtensions clientExtensionResults;
};

[SecureContext]
interface AuthenticatorResponse {
    readonly attribute ArrayBuffer clientDataJSON;
};

[SecureContext]
interface AuthenticatorAttestationResponse : AuthenticatorResponse {
    readonly attribute ArrayBuffer attestationObject;
};

[SecureContext]
interface AuthenticatorAssertionResponse : AuthenticatorResponse {
    readonly attribute ArrayBuffer      authenticatorData;
    readonly attribute ArrayBuffer      signature;
};

[equalsJeffH]

[SameObject] definition is here.

So it seems @jyasskin is asserting that all the readonly interface attrs in our collected WebAuthn IDL ought to be [SameObject]. Looks reasonable to me. I will effect the change.