relay-flow-types-installer

relay-flow-types-installer

This package installs Flow type definitions for all locally installed Relay packages. It's a workaround in waiting for https://github.com/facebook/relay/pull/2690 to land.

This is not a classic Flow libdef as seen in the flow-typed project. Rather, this is the actual typed source code exported alongside the built sources for Relay. This has a few implications:

• It's a full 1-to-1 of how the full Relay codebase was typed with Flow for that particular release.
• It means you'll need to tweak your .flowconfig to support all features and have all options needed to support how Relay's Flow types are written. More on that below.

Usage

You must have rsync installed and available to your shell.

Install the package:

yarn add --dev relay-flow-types-installer

Add it to your postinstall in package.json:

# package.json
"scripts": {
  ...
  "postinstall": "relay-flow-types-installer"
}

There, all set up!

Ugh, I get tons of Flow errors

Well, in order for this to work you'll need to tweak your .flowconfig to support all the things that that particular Relay release supported. To get this sorted it's recommended to look at the .flowconfig of the Relay release you're using and tweak your .flowconfig in accordance. You can find Relay's .flowconfig for any particular release by going to https://github.com/facebook/relay/blob/v5.0.0/.flowconfig and switching the version tag in the URL to your target version.

How it works

The package contains the Relay code base exported as .js.flow-files for Relay versions 2.0.0, 3.0.0, 4.0.0 and 5.0.0. It ships with a script that looks through your project package.json, finds Relay-related packages, and adds the Flow typed source alongside those packages right inside of your node_modules. This achieves the same thing as the PR mentioned above will, which is that the packages ship with their Flow types.

Following the instructions and setting up the script to run postinstall ensures that the types are always installed when you tweak or re-install your node_modules.