LiquidJava VS Code Extension

The LiquidJava VS Code extension adds support for refinement types, extending the Java standard type system directly inside VS Code, using the LiquidJava verifier. It provides error diagnostics and syntax highlighting for refinements.

Getting Started

GitHub Codespaces

To try out the extension on an example project without setting up your local environment:

1. Log in to GitHub
2. Click the button below
3. Select the 4-core option
4. Press Create codespace

The codespace will open in your browser and automatically install the LiquidJava extension shortly.

Local Setup

To set up the extension locally, install the LiquidJava extension in the VS Code Marketplace or the Open VSX Marketplace and add the liquidjava-api dependency to your Java project.

Maven

<dependency>
    <groupId>io.github.liquid-java</groupId>
    <artifactId>liquidjava-api</artifactId>
    <version>0.0.2</version>
</dependency>

Gradle

repositories {
    mavenCentral()
}

dependencies {
    implementation 'io.github.liquid-java:liquidjava-api:0.0.2'
}

Development

Developer Mode

To run the extension in developer mode, which automatically spawns the server in a separate process:

1. Open the client folder in VS Code
2. Run npm install
3. Make sure you have the Red Hat extension for Language Support for Java™ installed and enabled
4. Go to Run > Run Extension (or press F5)
5. A new VS Code instance will start with the LiquidJava extension enabled
6. Open a Java project containing the liquid-java-api.jar in the lib folder

Debugging Mode

To run the extension in debugging mode by manually starting the server and connecting the client to it:

• Run the server:

  • Open the server folder in your IDE
  • Run App.java, which will start the server on port 50000
  • View the server logs in the console

• Run the client:

  • Open the client folder in VS Code
  • Set the DEBUG variable to true in client/src/extension.ts
  • Go to Run > Run Extension (or press F5)
  • A new VS Code instance will open with the LiquidJava extension enabled, which will connect to the server on port 50000
  • Open a Java project containing the liquid-java-api.jar in the lib folder
  • View the client logs in the LiquidJava output channel or by clicking the status indicator

Create Server JAR

To build the language server, export it as a runnable JAR file named language-server-liquidjava.jar and place it in /client/server.

• In Eclipse:
  • Open the server folder
  • Select File > Export > Runnable JAR file
  • In the launch configuration, choose main - vscode-liquid-java-server
  • In the output path, choose the /client/server folder of this extension
• In VS Code:
  • Open the server folder
  • Use the Export Jar feature (Ctrl+Shift+P > Java: Export Jar)
  • Select App as the main class
  • Select OK
  • Copy the generated JAR from the root directory to the /client/server folder
• In IntelliJ:
  • Open the server folder
  • Go to File > Project Structure > Artifacts
  • Select Add a new Jar > From modules with dependencies
  • Select App as the main class
  • Build the artifact via Build > Build Artifacts > Build
  • Copy the generated JAR from the out/artifacts folder to the /client/server folder

Project Structure

• /server - Implements the Language Server Protocol (LSP) in Java using the LSP4J library
• /client - Implements the VS Code extension in TypeScript that connects to the language server using LSP
  • It depends on Language Support for Java™ for regular Java errors
• /lib - Contains the liquidjava-api.jar required for the extension to be activated in a Java project