caoccao/swc4j: swc4j (SWC for Java) is an ultra-fast JavaScript and TypeScript compilation and bundling tool on JVM.

// Prepare a simple TypeScript code snippet.
String code = "function add(a:number, b:number) { return a+b; }";
// Prepare a script name.
URL specifier = new URL("file:///abc.ts");
// Prepare an option with script name and media type.
Swc4jTranspileOptions options = new Swc4jTranspileOptions()
        .setSpecifier(specifier)
        .setMediaType(Swc4jMediaType.TypeScript);
// Transpile the code.
Swc4jTranspileOutput output = new Swc4j().transpile(code, options);
// Print the transpiled code.
System.out.println(output.getCode());

JavetSanitizerStatementListChecker checker = new JavetSanitizerStatementListChecker();

// 1. Check if keyword const can be used.
String codeString = "const a = 1;";
checker.check(codeString);
System.out.println("1. " + codeString + " // Valid.");

// 2. Check if keyword var can be used.
codeString = "var a = 1;";
try {
    checker.check(codeString);
} catch (JavetSanitizerException e) {
    System.out.println("2. " + codeString + " // Invalid: " + e.getMessage());
}

// 3. Check if Object is mutable.
codeString = "Object = {};";
try {
    checker.check(codeString);
} catch (JavetSanitizerException e) {
    System.out.println("3. " + codeString + " // Invalid: " + e.getMessage());
}