Refactoring flow of displaying optional add-ons prompts #260

[hanam1ni]

Issue

Regarding applying add-ons to the generated project, the current behavior of the template when applying optional add-ons is to display a prompt asking if the add-on is needed or not. If yes, the add-one is applied immediately.

The current flow can cause the issue when some add-ons need to apply differently based on whether the other specific add-on is applied or not. For example, the Wallaby add-on must include ExVCR.Mock to FeatureCase only when the ExVCR add-on is applied. (Check out this issue for more information)

For more clarification, here is another example. There are two add-ons. The first add-on must apply differently if the second add-on is applied (e.g. rename add configuration, rename some files). This can be solved by ordering a second add-on before the first add-on, but I think it is not a solid solution and prone to bugs if future developers do not seem aware that ordering is matters.

defp optional_addons_setup(%Project{} = project) do
    # This add-on needs to apply differently if the second addon is applied
    if install_addon_prompt?("First addon"), do: Web.FirstAddon.apply(project) 

    if install_addon_prompt?("Second addon), do: Web.SecondAddon.apply(project)
end

Besides the issue mentioned above, there may have more problems when the template grows and introduces more add-ons, and some of them can have different behavior depending on the applied add-ons.

Solution

Show all prompts for optional add-ons first and store the user response somewhere (Maybe, in the Project struct). After the user responds to all the prompts, start applying add-ons. With this flow, each add-on is aware of which other add-ons will be applied and can behave differently based on the context.

Who Benefits?

Developers

What's Next?

• Refactor the Phoenix template
• Refactor the Non-Phoenix template

[olivierobert]

It would indeed be simpler for creating more addons 💯