Resource Existence Checks

[jikuja]

During last community monthly call(link TBD) there was feedback request for new existing key word features: https://aka.ms/bicepREC

I could not find any new discussion about this and therefore I'm starting a new.

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Current documentation states following: If you attempt to reference a resource that doesn't exist, you get the NotFound error and your deployment fails. Check the name and scope of the resource you're trying to reference.

I've seen users multiple times abusing existing keyword with following explanation: "existing returns null if resources does not exists". Even some AVM modules are using this pattern.

Does proposed new annotation or existing? keyword changeset include changes for current existing logic?

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If current existing logic is not changed, will there be intellisense suggestion that warns user if they are checking if resource defined with existing is checked for being null?

TBH this should be added as soon as possible to avoid issues caused by usage of undocumented behaviour.

Multiple users had concerns with magical single character change. Would this kind of intellisense rule help them to use correct syntax?