gen_ex

A generic Elixir generator that doesn't require Phoenix.

I essentially want to create an Elixir tool similar to:

• https://www.cookiecutter.io/
• https://www.hygen.io/
• https://yeoman.io/

Concepts / Goals

• EEx Templates

  • Put custom templates in priv/templates.
  • Run mix gen <template_slug> <args> to generate files.
  • Each file in priv/templates represents a template that will generate a single file.
    • priv/templates/new_thing.ex can be used by running mix gen new_thing <args>.
  • Each subdirectory in priv/templates represents a set of templates that will generate multiple files
    • priv/templates/new_things/ can be used by running mix gen new_things <args>.
    • If a directory shares the name of a single-file template, the single-file template will be used. If there are subdirectories, the generated code will match the same directory structure.

• Tag metadata

  • The generator will tag generated files/modules with some sort of trackable metadata and version (similar to a Mix project).
  • It should allow manual editing of everything except the metadata tags.
  • You can get a list of all template usages and versions with mix gen.list <template_slug>
  • The generator will attempt to update old versions of templates via something like mix gen.update <template_slug> <new_version>.
    • If it can't, it will display code that needs to be manually added.

Links

Generic Elixir generators:

• https://hexdocs.pm/mix/Mix.Generator.html
• https://github.com/phoenixframework/phoenix/blob/main/lib/mix/phoenix.ex
• https://github.com/phoenixframework/phoenix/blob/main/installer/lib/phx_new/generator.ex
• https://github.com/phoenixframework/phoenix/blob/main/installer/lib/mix/tasks/phx.new.ex
• https://github.com/elixir-ecto/ecto/blob/master/lib/mix/tasks/ecto.gen.repo.ex
• https://github.com/pragdave/mix_generator
• https://github.com/zestcreative/elixirstream/blob/main/lib/utility/gen_diff/generator.ex

Phoenix generators:

• https://hexdocs.pm/phoenix/Mix.Tasks.Phx.Gen.html
• https://victorbjorklund.com/guide-to-custom-phoenix-phx-new-generator-mix-task
• https://fly.io/phoenix-files/customizing-phoenix-generators/

Code modification:

• https://github.com/doorgan/sourceror
  • Examples:
    • https://github.com/surface-ui/surface/blob/main/lib/mix/tasks/surface/surface.init.ex
    • https://github.com/liveshowy/webauthn_components/blob/main/lib/wac_gen/router.ex