src/test/groovy/ClosureAsParamTest.groovy

/*
 * Copyright 2003-2010 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package groovy

import java.util.concurrent.Callable

/**
 * Tests calling methods with Closures as parameters.
 *
 * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
 * @author Paul King
 * @version $Revision$
 */
class ClosureAsParamTest extends GroovyTestCase {

    int x

    void testSimpleBlockCall() {
        assert 'hello!' == assertClosure({ owner -> owner })
    }

    void testRunnable() {
        x = 0
        assertRunnable({ x = 1 })
        assert x == 1
    }

    void testCallable() {
        x = 0
        assert 'Callable' == assertCallable({ x = 2; 'Callable' })
        assert x == 2
    }

    void testRunnablePreferred() {
        x = 0
        assertRunnableAndCallable({ x = 3; 'result' })
        assert x == 6
    }

    void testCallableCoercion() {
        x = 0
        assert 'result' == assertRunnableAndCallable({ x = 3; 'result' } as Callable)
        assert x == 9
    }

    def assertClosure(Closure block) {
        assert block != null
        block.call("hello!")
    }

    def assertRunnable(Runnable r) {
        r.run()
    }

    def assertCallable(Callable c) {
        c.call()
    }

    def assertRunnableAndCallable(Runnable r) {
        r.run()
        x *= 2
    }

    def assertRunnableAndCallable(Callable c) {
        def result = c.call()
        x *= 3
        result
    }

}