Meta-data validation on variable out/in combinations in flows #283
Description
Currently, developer is responsible for ensuring the variable values are set before using. It is better for OfficeFloor to provide some errors/warnings indicating the In is being used before the Out has been injected to get the value for the variable.
In other words, In without previous out will always be null. Need to ensure there is Out always upstream of In.
Furthermore, can even ensure there is only one Out per flow to ensure values are not overwritten for variables.
Given, this may not always be to the developer's application, need @IgnoreVarValidation on parameter to enable developer to override the error