lex-codegen

Code generation engine for LegionIO extensions. Scaffolds complete lex-* gem trees from scratch, renders individual ERB templates, validates existing extension structure, and generates companion RSpec files. Used by the legion lex create CLI command and by agentic swarm pipelines.

Installation

Add to your Gemfile or gemspec:

gem'lex-codegen'

Or install directly:

gem install lex-codegen

Usage

Scaffold a complete extension

require'legion/extensions/codegen'client=Legion::Extensions::Codegen::Client.new(base_path: '/path/to/output')result=client.scaffold_extension(name: 'myextension',module_name: 'Myextension',description: 'Does something useful',helpers: ['config'],runner_methods: [{name: 'run_job',params: ['job_id:']},{name: 'check_status',params: ['job_id:','verbose: false']}])result[:success]# => trueresult[:path]# => '/path/to/output/lex-myextension'result[:files_created]# => 15

This writes a fully structured gem including gemspec, Gemfile, .rubocop.yml, GitHub Actions CI workflow, .rspec, .gitignore, LICENSE, version.rb, entry point, client, helpers, runners, and RSpec files for all of the above.

Generate a single file

result=client.generate_file(template_type: :runner,output_path: '/tmp/myrunner.rb',variables: {module_name: 'Myextension',gem_name_underscored: 'myextension',runner_class: 'RunJob',methods: [{name: 'run_job',params: ['job_id:']}]})result[:bytes]# => number of bytes written

Render a template to a string (without writing to disk)

runner=Legion::Extensions::Codegen::Runners::Templatecontent=runner.render_template(template_type: :version,variables: {module_name: 'Myextension',gem_version: '0.1.0'})putscontent[:content]# frozen_string_literal: true# module Legion::Extensions::Myextension; VERSION = '0.1.0'; end

List available templates

runner.list_templates# => { success: true, templates: [:gemspec, :gemfile, :rubocop, :ci, :rspec, :gitignore,# :license, :version, :entry_point, :spec_helper, :runner, :client] }

Inspect required variables for a template

runner.template_variables(template_type: :gemspec)# => { success: true, template_type: :gemspec,# required_variables: [:gem_name, :module_name, :description, :author, :email,# :ruby_version, :license, :extra_deps] }

Validate an existing extension

validator=Legion::Extensions::Codegen::Runners::Validate# Check directory structurevalidator.validate_structure(path: '/path/to/lex-myextension')# => { valid: true, missing: [], present: ['Gemfile', '.rubocop.yml', ...] }# Check rubocop configvalidator.validate_rubocop_config(path: '/path/to/lex-myextension')# => { valid: true, issues: [] }# Check gemspec fieldsvalidator.validate_gemspec(path: '/path/to/lex-myextension')# => { valid: true, issues: [], path: '/path/to/lex-myextension/lex-myextension.gemspec' }

Generate spec files directly

spec_gen=Legion::Extensions::Codegen::Helpers::SpecGenerator.new# Runner specputsspec_gen.generate_runner_spec(module_name: 'Myextension',runner_name: 'run_job',methods: [{name: 'run_job',params: ['job_id:']}])# Client specputsspec_gen.generate_client_spec(module_name: 'Myextension')# Helper specputsspec_gen.generate_helper_spec(module_name: 'Myextension',helper_name: 'config',methods: [{name: 'load',params: []}])

Available Templates

Template	Generates
gemspec	lex-name.gemspec
gemfile	Gemfile with gemspec + test group
rubocop	.rubocop.yml with LegionIO defaults
ci	.github/workflows/ci.yml (calls shared reusable workflow)
rspec	.rspec with --format documentation
gitignore	.gitignore with standard Ruby entries
license	LICENSE (MIT)
version	lib/legion/extensions/<name>/version.rb
entry_point	lib/legion/extensions/<name>.rb
spec_helper	spec/spec_helper.rb with Legion::Logging stub
runner	One runner module with stubbed methods
client	Client class including runner modules

Defaults

Setting	Default
Ruby version	3.4
License	MIT
Author	Esity
Email	matthewdiverson@gmail.com
Gem version	0.1.0

Development

bundle install
bundle exec rspec
bundle exec rubocop

License

MIT. See LICENSE.