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 relay-compiler --dev
yarn add typescript relay-compiler-language-typescript --dev
Note: Starting with version 15.0.0 relay-compiler-language-typescript requires a minimum TypeScript version of 4.5.0 being installed in your project.
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 (or higher) and leave transpilation to CommonJS
modules (if required)
up to Babel with the following tsconfig.json
settings:
{
"compilerOptions": {
"module": "ES2015", // ES2015 or higher
"target": "ES2020" // best use the highest target setting compatible with your Babel setup
}
}
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`
...
`
);
… which makes it impossible for babel-plugin-relay
to find the locations
where the graphql
function is being used.
The generated code uses ES2015 module syntax if module
is set to ES2015 or
higher in your tsconfig.json
. Note that the eagerESModules
option from
relay-compiler
has no effect on the generated code if module
is ES2015 or
higher.
Custom Headers
If you need to add a custom header to generated files, perhaps for a custom linter
or to get boilerplate license code in, that can be passed in also in compilerOptions
as banner
:
{
"compilerOptions": {
"banner": "/* © 2021 Example.org - @generated code */"
}
}
Problems
React Hot Loader
React Hot Loader is known to not always work well with generated code such as our typing artifacts, 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.
Also see
- 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.
- There are Relay tslint rules available here.
License
This package is available under the MIT license. See the included LICENSE file for details.