relay-compiler-language-tw-typescript

relay-compiler-language-typescript

A language plugin for Relay that adds TypeScript support, including emitting type definitions.

Installation

Add the package to your dev dependencies:

yarn add graphql-compiler --dev
yarn add typescript relay-compiler-language-typescript --dev

Configuration

relay-compiler

Then configure your relay-compiler script to use it, like so:

{
  "scripts": {
    "relay": "relay-compiler --src ./src --schema data/schema.graphql --language typescript --artifactDirectory ./src/__generated__"
  }
}

This is going to store all artifacts in a single directory, which you also need to instruct babel-plugin-relay to use in your .babelrc:

{
  "plugins": [
    ["relay", { "artifactDirectory": "./src/__generated__" }]
  ]
}

TypeScript

Also be sure to configure the TypeScript compiler to transpile to es2015 modules and leave transpilation to commonjs modules up to Babel with the following tsconfig.json settings:

{
  "compilerOptions": {
    "target": "es2015",
    "module": "es2015"
  }
}

The reason for this is that tsc would otherwise generate code where the imported graphql function is being namespaced (react_relay_1 in this example):

react_relay_1.createFragmentContainer(MyComponent, react_relay_1.graphql `
  ...
`);

…and this makes it impossible for babel-plugin-relay to find the locations where the graphql function is being used.

Note that this does mean you need to configure Babel to transform the ES module import and export statements, by using the babel-plugin-transform-es2015-modules-commonjs transform plugin, if you’re not already.

Problems

React Hot Loader

React Hot Loader is known to not always work well with generated code such as our typing artefacts, which will lead to loading modules with TypeScript types into the browser and break. As a maintainer of RHL pointed out in a similar issue:

The problem - hot reloading is not "complete"

So until RHL will be made “complete” this project can’t gurantee to always work well with it, nor is it our control to do anything about that.

Examples

You can find a copy of the Relay example TODO app inside this repository or you can take a look at the Artsy React Native app.

License

This package is available under the MIT license. See the included LICENSE file for details.