Crystal Source Typer

This is a crystal tool that adds missing types to Crystal source code for def statements.

This tool is very much in alpha! Anything should be considered up for change, including the repository itself.

Installation

Due to dependency on llvm in the semantic layer, LLVM 18+ will be needed to successfully build this tool. See this for details.

Add to your shard.yml file:

development_dependencies:
  source-typer:
    github: Vici37/cr-source-typer

And run shards install. A new build tool bin/typer should now exist.

Usage

As always, you can always use the -h flag to get basic help instructions:

> ./bin/typer -h

When using it, the typer utility should be provided your entrypoint (the same crystal file used with crystal build) and 0 or more definition locators, or places where you want typing added if it's missing. Definition locators come in 4 "flavors":

• A directory name - all crystal code under that directory (recursive) will be typed
• A filename - all defs in that file will be typed
• A filename:line_number format - only add typing to the definition on this line
• A filename:line_number:column_number format - only add typing to a definition where the character d is on this line / column (unlikely to be used, but there it is)

Providing 0 definition locators is the same as providing either the 'src' directory (if it exists) or the current directory (if it doesn't). Trying to type the 'lib' directory can lead to a bad time.

Assume there's a local file hello.cr with contents:

def hello(world)
  world
end

class Test
  def self.hello(world)
    0_u64
  end

  def hello
    "world"
  end
end

def i_am_not_called
  0
end

hello(37)
Test.hello("test")
Test.new.hello

Then running command ./typer hello.cr will overwrite it with:

def hello(world : Int32) : Int32
  world
end

class Test
  def self.hello(world : String) : UInt64
    0_u64
  end

  def hello : String
    "world"
  end
end

def i_am_not_called
  0
end

hello(37)
Test.hello("test")
Test.new.hello

Note: Only definitions that are called get typed. Unused methods won't be typed by crystal's semantic layer.

Development

> git clone <this repo>
> cd <this repo>
> shards install
> make build
> make test

Contributing

1. Fork it (https://github.com/Vici37/cr-source-typer/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• Troy Sornson - creator and maintainer