Environment

• Elixir version (elixir -v): 1.16.0
• Phoenix version (mix deps): 1.7.10
• Operating system: macOS 14.2.1

Actual Behavior

1. mix phx.new foo --umbrella
2. cd foo_umbrella/apps
3. mix phx.new.web bar
4. cd ..
5. mix

There are a couple errors that occur:

• Related to the appended configuration in config/config.exs:

  config :bar,
    ecto_repos: [Bar.Repo],
    generators: [context_app: false]

  Bar.Repo should not exist in the context of specifically a web application. It is inconsistent with the generated foo_web configuration:

  config :foo_web,
    ecto_repos: [Foo.Repo],
    generators: [context_app: :foo]

• Related to the generated bar/test/support/conn_case.exs file:

  Bar.DataCase.setup_sandbox(tags)

  Similar to the above, I don't believe this should exist and should instead reference the dependent support module. Also inconsistent with the generated foo_web config:

  Foo.DataCase.setup_sandbox(tags)

Expected Behavior

The app should be able to be compiled when a new web app is generated in the context of an umbrella app.

Proposed Solution

Adding something like a --depends-on flag to the phx.new.web generator so that the backing app can be specified in the generator. The additional context of the flag would also enable adding {:foo, in_umbrella: true}, automatically to deps inside of bar/mix.exs

Example:

mix phx.new.web bar --depends-on foo

Resulting in:

# config/config.exs
config :bar,
  ecto_repos: [Foo.Repo],
  generators: [context_app: :foo]

# bar/test/support/conn_case.exs
Foo.DataCase.setup_sandbox(tags)

# bar/mix.exs
defp deps do
  [
    . . .
    {:foo, in_umbrella: true}
  ]
end