Added tests.

src/java/org/codehaus/groovy/grails/plugins/batch/DefaultGrailsMainClass.java

@@ -33,8 +33,9 @@ public DefaultGrailsMainClass(Class<?> clazz) {
     @SuppressWarnings("serial")
     private static Closure BLANK_CLOSURE = new Closure(
             DefaultGrailsMainClass.class) {
-        @Override
-        public Object call(Object[] args) {
+
+        @SuppressWarnings("unused")
+        public Object doCall(Object[] args) {
             return null;
         }
     };

src/java/org/codehaus/groovy/grails/plugins/batch/Launcher.java

@@ -161,16 +161,18 @@ public void destroy() {
                 GrailsApplication grailsApplication = ApplicationHolder
                         .getApplication();
 
-                DefaultGrailsMainClass main = getMainClass(grailsApplication);
-                if (main != null) {
-                    main.callDestroy();
-                }
+                if (grailsApplication != null) {
+                    DefaultGrailsMainClass main = getMainClass(grailsApplication);
+                    if (main != null) {
+                        main.callDestroy();
+                    }
 
-                GrailsClass[] bootstraps = grailsApplication
-                        .getArtefacts(BootstrapArtefactHandler.TYPE);
-                for (int i = bootstraps.length - 1; i >= 0; i--) {
-                    GrailsClass bootstrap = bootstraps[i];
-                    ((GrailsBootstrapClass) bootstrap).callDestroy();
+                    GrailsClass[] bootstraps = grailsApplication
+                            .getArtefacts(BootstrapArtefactHandler.TYPE);
+                    for (int i = bootstraps.length - 1; i >= 0; i--) {
+                        GrailsClass bootstrap = bootstraps[i];
+                        ((GrailsBootstrapClass) bootstrap).callDestroy();
+                    }
                 }
 
                 {

test/integration/org/codehaus/groovy/grails/plugins/batch/LauncherTests.groovy

@@ -0,0 +1,16 @@
+package org.codehaus.groovy.grails.plugins.batch
+
+import static org.junit.Assert.*
+
+
+class LauncherTests extends GroovyTestCase {
+
+    void test() {
+        /*
+        System.setProperty "${Launcher.PROPERTY_PREFIX}resourcePath", 'web-app'
+        Launcher.main(new String [0])
+        System.setProperty "${Launcher.PROPERTY_PREFIX}resourcePath", null
+        */
+    }
+
+}

test/unit/org/codehaus/groovy/grails/plugins/batch/DefaultGrailsMainClassTests.groovy

@@ -0,0 +1,59 @@
+package org.codehaus.groovy.grails.plugins.batch
+
+import grails.test.*
+
+import org.codehaus.groovy.grails.plugins.batch.DefaultGrailsMainClass
+
+
+class DefaultGrailsMainClassTests extends GrailsUnitTestCase {
+
+    private GroovyClassLoader classLoader
+
+    void testEmptyClass() {
+        def mainClass = 'class Main {\
+        }'
+        mainClass = classLoader.parseClass(mainClass)
+        DefaultGrailsMainClass grailsMainClass = new DefaultGrailsMainClass(mainClass)
+        assertNotNull('initClosure is not null', grailsMainClass.initClosure)
+        assertNotNull('runClosure is not null', grailsMainClass.runClosure)
+        assertNotNull('destroyClosure is not null', grailsMainClass.destroyClosure)
+
+        grailsMainClass.callInit()
+        grailsMainClass.callRun([a:1])
+        grailsMainClass.callDestroy()
+    }
+
+
+    void testRegularClass() {
+        def mainClass = 'class Main {\
+        String step = null;\
+        def init = {-> step = "init";};\
+        def run = {Map context -> step = "run";};\
+        def destroy = {-> step = "destroy";};\
+        }'
+        mainClass = classLoader.parseClass(mainClass)
+        DefaultGrailsMainClass grailsMainClass = new DefaultGrailsMainClass(mainClass)
+        assertNotNull('initClosure is not null', grailsMainClass.initClosure)
+        assertNotNull('runClosure is not null', grailsMainClass.runClosure)
+        assertNotNull('destroyClosure is not null', grailsMainClass.destroyClosure)
+
+        def mainInstance = grailsMainClass.referenceInstance 
+        assertNull mainInstance.step 
+        grailsMainClass.callInit()
+        assertEquals 'init', mainInstance.step
+        grailsMainClass.callRun([a:1])
+        assertEquals 'run', mainInstance.step
+        grailsMainClass.callDestroy()
+        assertEquals 'destroy', mainInstance.step
+    }
+
+
+    @Override
+    protected void setUp() {
+        super.setUp()
+
+        this.classLoader = new GroovyClassLoader(Thread.currentThread().contextClassLoader?:this.class.classLoader)
+    }
+
+
+}