Jenerator

JSON Document ⇨ Crystal type definitions

Jump-start your next JSON API client by generating types from a sample API response!

The results this outputs are meant as a starting off point, to eliminate having to write a lot of the boilerplate involved in creating a new project to parse the response from an API, without resorting to the runtime overhead of relying on JSON.parse. You will probably want to review the generated code and make some revisions, especially if your data sample includes arrays of objects (see Known Issues).

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     jenerator:
       github: dscottboggs/jenerator
   

2. Run shards install

Usage

require "jenerator"

sample = %[{"data": "just some text", "listOfData": ["one", 2, 3.0]}]
puts Jenerator.process sample

The above code sample would output this Crystal code:

require "json"

class Document
  include JSON::Serializable
  @data : String
  @[JSON::Field(key: "listOfData")]
  @list_of_data : Array(String | Int64 | Float64)
end

There's also a compiled script which you can download as a static binary from the "releases" page which will generate new Crystal source files for each .json file in a directory.

Known issues:

When generating code for an array of objects, a new class or struct is generated for each object member of that array. The resulting type eliminates redundant types from the union, but the types are still declared.

See jenerator_spec.cr for an example.

Contributing

1. Fork it (https://github.com/dscottboggs/jenerator/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

• D. Scott Boggs - creator and maintainer