association
Within a factory block, use the association
method to always make an
additional object alongside this one. This name best makes sense within the
context of ActiveRecord.
The association
method takes a mandatory name and optional options.
The options are zero or more trait names (Symbols), followed by a hash of attribute overrides. When constructing this association, factory_bot uses the trait and attribute overrides given.
See method_missing for a shorthand. See build strategies for an explanation of how each build strategy handles associations.