Fix a false positive for Rails/NotNullColumn when adding a :virtual column

[fatkodima]

Fixes #887.

From documentation:

Several restrictions apply to the definition of generated columns and tables involving generated columns:

• A generated column cannot have a column default or an identity definition.

[koic]

include? is a partial match, so I'm worried about false positives. What about below?

Suggested change

	return if type.source.include?('virtual')
	return if type.source == ':virtual'

[fatkodima]

It is possible to specify column types as a string (while not as popular as symbol) or a symbol, so I tried to match both. Do you think we can skip it?

[koic]

IMO, It's a corner case, but I think String#include? is not suitable because it matches all strings containing virtual. This patch will need to add a test case for column types as a string and updating an appropriate logic.

[fatkodima]

Added explicit check and a test case.

[koic]

type.value should be used instead of type.source to detect double quoted "virtual".

Suggested change

	return if type.source == ':virtual' || type.source == "'virtual'"
	return if type.value == :virtual || type.value == 'virtual'

[fatkodima]

🤦 Thanks! Fixed.

[koic]

Thanks!

[MrJoy]

Thank you!