Development Setup

Prerequisites

Requirement

Version

JDK

21 or later

IntelliJ IDEA

2025.3+ (Ultimate or Community)

Git

Any recent version

Node.js

For testing LSP features

Clone the Repository

git clone https://github.com/Nagatatz/rescript-intellij-plugin.git
cd rescript-intellij-plugin

Open in IntelliJ IDEA

  1. Open IntelliJ IDEA

  2. File → Open → Select the cloned repository

  3. IntelliJ will detect the Gradle project and import it automatically

  4. Wait for the Gradle sync to complete (this downloads dependencies)

Verify the Setup

Run the build to ensure everything is configured correctly:

./gradlew buildPlugin

This will:

  1. Generate the JFlex lexer (RescriptFlexLexer.java) from Rescript.flex

  2. Compile all Kotlin source code

  3. Run ktlint checks

  4. Package the plugin

Run a Development IDE Instance

./gradlew runIde

This launches a fresh IntelliJ IDEA instance with the plugin loaded. You can open a ReScript project in this instance to test your changes.

Project JDK Configuration

If IntelliJ doesn’t automatically detect your JDK:

  1. File → Project Structure → Project

  2. Set SDK to JDK 21+

  3. Set Language level to 21