feat: @W-12539773 add isNearMembraneProxyMaskedFunction() #420
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| } | ||
| const result = ReflectGet(target, key, receiver); | ||
| if (result !== undefined && isProxyMaskedSymbol) { | ||
| throw new TypeErrorCtor(ERR_ILLEGAL_PROPERTY_ACCESS); |
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why throwing instead of just returning undefined?
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Because this is a guard for when a user is faking this. Instead of silently failing when we detect this kind of level of forgery since it is for the identification of our masking and proxies we throw a hard error. No user code should ever be doing this (trying to pass off this symbol as their own).
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Essentially before we were playing nice and when, in the case of forging we would simply return undefined and not recognize it, but identification of masked and proxied values is becoming more critical (so we don't want to fail the check). Now there is no wiggle room for possible forgeries and if a user is trying to forge something we should error and say "No, don't do that".
| defineProperty(target: ProxyTarget, key: PropertyKey, desc: PropertyDescriptor) { | ||
| lastProxyTrapCalled = ProxyHandlerTraps.DefineProperty; | ||
| if (key === LOCKER_NEAR_MEMBRANE_PROXY_MASKED_SYMBOL) { | ||
| throw new TypeErrorCtor(ERR_ILLEGAL_PROPERTY_ACCESS); |
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why not just returning false?
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This is a forgery guard.
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feat: @W-12539773 add
isNearMembraneProxyMaskedFunction()