Reactor JavaScript (Nashorn) Support

This is the Nashorn-based JavaScript support for the Reactor JVM framework.

Core

TODO : Some of the testing components will be moved over to core at some point.

Testing

These components provide helpers for running unit and integration tests in JUnit and providing bi-directional communication between Java and JavaScript.

To write tests in JavaScript and run them from JUnit, create a JavaScript file that exports a module for use by the test Runner (we'll call this my-tests.js and put it in the src/test/resources directory):

var component = require("component");

(function (global) {

  global.jsIntegrationTest = function () {
    // do some testing
    var real = component.testMethod();

    assertThat("Result is as expected", real, is("expected"));
  }

})(this);

Note: All static methods from org.junit.Assert and org.hamcrest.CoreMatchers are imported into the global namespace to make it easier to write assertions and matchers.

To access and interact with this test from JUnit, just create a normal JUnit test class but annotate it with a @RunWith annotation:

import reactor.js.test.JavaScriptTests;
import reactor.js.test.NashornJUnitTestRunner;

import org.junit.Test;
import org.junit.runner.RunWith;

@RunWith(NashornJUnitTestRunner.class)
@JavaScriptTests(module = "my-tests", paths = {"src/test/resources"})
public class MyIntegrationTests {

    @Test
    public void jsIntegrationTest() {}

}

When you run this JUnit test, it will bootstrap a Nashorn environment and provide all the necessary helpers to invoke your JavaScript. Your module is expected to export a function that matches the name of a method in the JUnit test class that is annotated with @Test.

Some things to note in this quick example:

The NashornJUnitTestRunner will run "normal" JUnit tests if there is no matching JavaScript function.
The test runner will run your test method AS WELL AS your JavaScript test function. If an error is thrown from either one, the test will fail.
Bi-directional communication is possible between JUnit and JavaScript

Talking to JavaScript (and visa versa)

Bi-directional communication is possible with the NashornJUnitTestRunner. It will transfer your test class' properties into the JavaScript environment and the return value from your test function will be set into a field on your test class annotation with @TestResult.

Here is an example of extending the above test to talk to JavaScript:

var component = require("component");

(function (global) {

  global.jsIntegrationTest = function () {
    // comes from MyIntegrationTests.greeting
    var greeting = global.greeting;

    // do some testing, passing the value from Java
    var real = component.testMethod(greeting);

    assertThat("Result is as expected", real, is("Hello World!"));

    return real;
  }

})(this);

import reactor.js.test.JavaScriptTests;
import reactor.js.test.NashornJUnitTestRunner;
import reactor.js.test.TestResult;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.MatcherAssert.assertThat;

@RunWith(NashornJUnitTestRunner.class)
@JavaScriptTests(module = "my-tests", paths = {"src/test/resources"})
public class MyIntegrationTests {

    @TestResult
    String realResult;
    String greeting;

    @Before
    public void setup() {
        this.realResult = "Hello World!";
    }

    @Test
    public void jsIntegrationTest() {
        assertThat("JavaScript value was returned", realResult, is("Hello World!"));
    }

}

reactor-js is Apache 2.0 licensed.

linushub/reactor-js

Reactor JavaScript (Nashorn) Support

Core

Testing

Talking to JavaScript (and visa versa)