@lekko/ts-tools

Requirements

An up-to-date version of the Lekko CLI installed on the system is required for most of this library's components for translating changes in TypeScript files to local config repos.

brew tap lekkodev/lekko
brew install lekko

Packages

@lekko/ts-transformer

Installation

npm install -D @lekko/ts-transformer

Usage

In tsconfig.json:

{
  ...
  "compilerOptions": {
    ...
    "plugins": [
      { "transform": "@lekko/ts-transformer", "transformProgram": true }
    ]
  }
}

Then use with tspc

@lekko/vite-plugin

Installation

npm install -D @lekko/vite-plugin

Usage

In vite.config.js:

import lekko from "@lekko/vite-plugin";

export default defineConfig({
  plugins: [lekko(), react()],
  ...
});

TODOs

Full ruleslang

Other comparison operators, bucketing, etc.

Automatic install script

Especially for Node projects, we should provide an automatic install script that updates users' tsconfig.json, package.json, etc. in one command.

E2E tests

• Make the transformer testable, which also benefits "documenting" known, supported native lang syntaxes and different tsconfig options.
• Testing setup can remove dependency on CLIs and filesystem (but could start with them)
• In the long term with support for other languages we probably want a full conformance testing suite

Performance

The end-to-end program transformation is quite slow at the moment and noticeably increases build times e.g. when using the Vite plugin. We should profile/benchmark this, but a few intuitive potential improvements:

• We make a lot of calls to executables e.g. Lekko CLI, Buf CLI
  • Especially for Lekko CLI, we should try to implement batch commands that can e.g. generate starlark for all configs in one go
  • We should investigate if we can call Buf's ES protoc plugin as a library rather than via the CLI
• We make a lot of synchronous fs I/O calls
  • See if there's things we can do virtually
  • See if we can refactor to be able to take advantage of async fs APIs
• For bundler plugins, we might want to look at implementing a watcher that can handle incremental changes instead of dealing with the whole transformed program on each build.

HMR support