Conditionally updating resources

Hey chaps

I posed a previous question about lambda module but realise my question is a little more generic.

The lack of conditional logic in TF is a bit painful at times. I know there’s ways to avoid creating a resource conditionally using count 0 but I find a bit of a grey area between “creating” a resource and updating a resource.

A resource like lamda alias might need regular updates. But I can’t conditionally apply this because count = 0 for an existing object causes a destroy (rather than ignore)

You can use lifecycle rules to some extent but not afaik to skip something based on a flag or variable.

So my general question is , if your state file contains a resource you created. , is there anyway to conditionally allow the resource to update without it getting destroyed ?