Phoenix: Blog.Blog.Blog.Post.__struct__/1 is undefined, cannot expand struct Blog.Blog.Blog.Post

[wintermeyer]

Environment

• Elixir version (elixir -v): 1.8.0
• Phoenix version (mix deps): 1.4.0
• NodeJS version (node -v): 8.8.1
• NPM version (npm -v): 5.4.2
• Operating system: macOS 10.14.2

Expected behavior

$ mix phx.new blog
$ cd blog
$ mix ecto.create
$ mix phx.gen.html Blog Post posts title body:text
$ vim lib/blog_web/router.ex # adding the route
$ mix ecto.migrate

Actual behavior

$ mix phx.new blog
$ cd blog
$ mix ecto.create
$ mix phx.gen.html Blog Post posts title body:text
$ vim lib/blog_web/router.ex # adding the route
$ mix ecto.migrate
Compiling 6 files (.ex)

== Compilation error in file lib/blog_web/controllers/post_controller.ex ==
** (CompileError) lib/blog_web/controllers/post_controller.ex:13: Blog.Blog.Blog.Post.__struct__/1 is undefined, cannot expand struct Blog.Blog.Blog.Post
    lib/blog_web/controllers/post_controller.ex:12: (module)
    (stdlib) erl_eval.erl:680: :erl_eval.do_apply/6

If mix phx.new blog and mix phx.gen.html Blog Post posts title body:text don't mix then there should be an error message from mix phx.gen.html. Alternatively it should work without the error afterwords.

[Gazler]

Error is caused by:

  alias Blog.Blog
  alias Blog.Blog.Post

When alias Blog.Blog.Post is called, because Blog.Blog is already aliased, Blog references Blog.Blog and Post becomes Blog.Blog.Blog.Post

[josevalim]

Yeah, we should not allow someone to create a context with the same name as the app.

[achempion]

Looks like a new rule in validate_args! would be a good fit

[josevalim]

Yes!

José Valimwww.plataformatec.com.br
http://www.plataformatec.com.br/Founder and Director of R&D

[achempion]

I would like to implement that.
Any suggestions about the message would be great) but we can discuss it later

[josevalim]

“Cannot generate context Blog because it has the same name as the
application”

What do you think?

José Valimwww.plataformatec.com.br
http://www.plataformatec.com.br/Founder and Director of R&D