@gel/generate: Code generation tools for Gel

The @gel/generate package implements a set of code generation tools that are useful when developing an Gel-backed applications with TypeScript/JavaScript.

✨ View Documentation >>

Installation

If you're using Deno, you can skip this step.

Install the gel package.

$ npm install gel       # npm users
$ yarn add gel          # yarn users

Then install @gel/generate as a dev dependency.

$ npm install @gel/generate --save-dev      # npm users
$ yarn add @gel/generate --dev              # yarn users

Run a generator

Run a generator with the following command.

Node.js

$ npx @gel/generate <generator> [options]

Deno

$ deno run --allow-all npm:@gel/generate <generator> [options]

The value of <generator> should be one of the following.

• queries: This generator scans your project for *.edgeql files and generates a file containing a strongly-typed function for each.
• edgeql-js: This generator introspects your database schema and generates a query builder.
• interfaces: This generator introspects your database schema and generates TypeScript interfaces for each object type.

Third-party generators

✨ If you build a code generator for Gel, ping us or open a PR and we'll list it here! ✨

The gel package exports a set of utilities to introspect the schema and analyze queries. We use this same set of tools to implement the first-party generators.

import { createClient, $ } from "gel";

const client = createClient();

const types = await $.introspect.types(client);
// Map<string, Type>

const queryData = await $.analyzeQuery(client, `select 2 + 2`);
// {args: string; result: string; ...}

Contributing

If you want to implement a code generator, please open an issue first. This package only contains first-party generators with widespread appeal. From the root directory:

yarn
yarn workspaces run build  # build all packages

Navigate into packages/generate:

Build @gel/generate

yarn build

Build without typechecking (uses esbuild):

yarn build:fast

Run a generator:

npx @gel/generate edgeql-js    # query builder
npx @gel/generate queries      # query files

Execute playground.ts (uses tsx). Useful for testing things quickly in development:

yarn play

⚠️ All imports from "gel" resolve to the local build version of the driver in packages/gel/dist. This imports the built library, not the so you need to re-run yarn workspace gel build for changes to be reflected in your playground code. Run yarn dev watcher inside packages/gel to rebuild the project anytime you make a change.

Run commands in watch mode. Useful when in development. The following command rebuilds the package and executes the playground whenever a file change is detected.

yarn watch 'yarn build:fast && yarn play`

Run tests.

yarn test