Sai is a runtime environment for programs written in ECMAScript 5.1 that runs on top of JVM. This project forked from Nashorn.

• ECMAScript 5.1 implementation
• Runs on JVM (Java 21+)
• JSR-223 Script Engine API support
• High performance bytecode generation using ASM library

JAR file is available in Maven repository. Add the following dependency to your pom.xml:

<dependency>
    <groupId>org.codelibs</groupId>
    <artifactId>sai</artifactId>
    <version>0.3.0</version>
</dependency>

Add the following dependency to your build.gradle:

dependencies {
    implementation 'org.codelibs:sai:0.3.0'
}

Or in build.gradle.kts:

dependencies {
    implementation("org.codelibs:sai:0.3.0")
}

See CONTRIBUTING.md for the project layout, the script test convention, and how to narrow a test run.

• Java 21. The build declares a Java 21 toolchain, so Gradle provisions one if needed.
• No local Gradle install; use the wrapper.

# Full build (compile, test, javadoc, jar)
./gradlew build

# Clean build artifacts
./gradlew clean

# Create JAR only
./gradlew jar

# Run tests
./gradlew test

# Run tests in optimistic mode
./gradlew testOptimistic

# Run tests in pessimistic mode
./gradlew testPessimistic

# Generate Javadoc
./gradlew javadoc

# Generate API Javadoc only
./gradlew javadocApi

# Run a sample JavaScript file
./gradlew run

# Debug mode with code inspection
./gradlew debug

# Run all tests
./gradlew test

# Run test262 ECMAScript compliance tests
./gradlew test262

# Run test262 in parallel
./gradlew test262Parallel

# Download external test suites
./gradlew downloadExternals

After building, you'll find the following artifacts in build/libs/:

• sai-X.X.X.jar - Main JAR file
• sai-X.X.X-sources.jar - Source code JAR
• sai-X.X.X-javadoc.jar - Javadoc JAR

Note that ./gradlew compileJava on its own does not produce a usable engine: the @ScriptClass types are instrumented after compilation and only the JAR carries the result. Build jar, or anything that depends on it.

Bug reports and pull requests are welcome - see CONTRIBUTING.md. For security issues, follow SECURITY.md rather than opening an issue.

GPLv2 with the Classpath Exception, inherited from Nashorn. See LICENSE and ASSEMBLY_EXCEPTION. Code bundled from other projects is listed in NOTICE.