1 Commits (cb181e96d0440ec43774e2ed28107361e4fdbffb)

Author	SHA1	Message	Date
James Bardin	f0a64eb456	configs: explicitly nullable variable values ... The current behavior of module input variables is to allow users to override a default by assigning `null`, which works contrary to the behavior of resource attributes, and prevents explicitly accepting a default when the input must be defined in the configuration. Add a new variable attribute called `nullable` will allow explicitly defining when a variable can be set to null or not. The current default behavior is that of `nullable=true`. Setting `nullable=false` in a variable block indicates that the variable value can never be null. This either requires a non-null input value, or a non-null default value. In the case of the latter, we also opt-in to the new behavior of a `null` input value taking the default rather than overriding it. In a future language edition where we make `nullable=false` the default, setting `nullable=true` will allow the legacy behavior of `null` overriding a default value. The only future configuration in which this would be required even if the legacy behavior were not desired is when setting an optional+nullable value. In that case `default=null` would also be needed and we could therefor imply `nullable=true` without requiring it in the configuration.	5 years ago