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Groovy example source code file (ExpandoMetaClassCreationHandleTest.groovy)

This example Groovy source code file (ExpandoMetaClassCreationHandleTest.groovy) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Groovy tags/keywords

arraylist, bob, emcinherittest, emcinherittest, expandometaclass, expandometaclass, foo, fred, hello, metaclass, string, string, test1, test1

The Groovy ExpandoMetaClassCreationHandleTest.groovy source code

/*
 * Copyright 2004-2009 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.lang;

/**
 * @author Graeme Rocher
 */
class ExpandoMetaClassCreationHandleTest extends GroovyTestCase {
    def registry = GroovySystem.metaClassRegistry
    MetaClass savedStringMeta
    MetaClass savedObjectMeta

    void setUp() {
        savedStringMeta = registry.getMetaClass(String)
        savedObjectMeta = registry.getMetaClass(Object)
        ExpandoMetaClass.enableGlobally()
    }

    void tearDown() {
        ExpandoMetaClass.disableGlobally()
        registry.setMetaClass(String, savedStringMeta)
        registry.setMetaClass(Object, savedObjectMeta)
    }

    void testInheritWithExistingMetaClass() {
        registry.removeMetaClass(String)
        registry.removeMetaClass(Object)

        String foo = "hello"
        assertEquals "HELLO", foo.toUpperCase()

        Object.metaClass.doStuff = {-> delegate.toString().toUpperCase() }

        assertEquals "HELLO", foo.doStuff()
    }

    void testInheritFromInterfaceHierarchy() {
        registry.removeMetaClass(IBar)
        registry.removeMetaClass(Foo)
        registry.removeMetaClass(Test1)

        def metaClass = registry.getMetaClass(IBar)
        assertTrue(metaClass instanceof ExpandoMetaClass)

        metaClass.helloWorld = {-> "goodbye!" }

        def t = new Test1()
        assertEquals "goodbye!", t.helloWorld()
    }

    void testExpandoInterfaceInheritanceWithOverrideDGM() {
        registry.removeMetaClass(Foo)
        registry.removeMetaClass(Test1)

        def metaClass = registry.getMetaClass(Foo)
        assertTrue(metaClass instanceof ExpandoMetaClass)

        def map = [:]
        metaClass.getAt = {Integer i -> map[i] }
        metaClass.putAt = {Integer i, val -> map[i] = val }

        def t = new Test1()
        //assertEquals 2, t.metaClass.getExpandoMethods().size()
        //assert t.metaClass.getExpandoMethods().find { it.name == 'putAt' }

        t[0] = "foo"

        assert map.size() == 1

        assertEquals "foo", t[0]
    }

    void testOverrideSetPropertyViaInterface() {
        registry.removeMetaClass(Foo)
        registry.removeMetaClass(Test1)

        def metaClass = registry.getMetaClass(Foo)

        def testValue = null
        metaClass.setProperty = {String name, value ->
            def mp = delegate.metaClass.getMetaProperty(name)
            if (mp) { mp.setProperty(delegate, value) } else { testValue = value }
        }

        def t = new Test1()

        t.name = "Bob"
        assertEquals "Bob", t.name

        t.foo = "bar"
        assertEquals "bar", testValue
    }

    void testOverrideGetPropertyViaInterface() {
        registry.removeMetaClass(Foo)
        registry.removeMetaClass(Test1)

        def metaClass = registry.getMetaClass(Foo)

        metaClass.getProperty = {String name ->
            def mp = delegate.metaClass.getMetaProperty(name)
            mp ? mp.getProperty(delegate) : "foo $name"
        }

        def t = new Test1()

        assertEquals "Fred", t.getProperty("name")
        assertEquals "Fred", t.name
        assertEquals "foo bar", t.getProperty("bar")
        assertEquals "foo bar", t.bar
    }

    void testOverrideInvokeMethodViaInterface() {
        registry.removeMetaClass(Foo)
        registry.removeMetaClass(Object)
        registry.removeMetaClass(IBar)
        registry.removeMetaClass(Test1)

        def metaClass = registry.getMetaClass(Foo)

        metaClass.invokeMethod = {String name, args ->
            def mm = delegate.metaClass.getMetaMethod(name, args)
            mm ? mm.invoke(delegate, args) : "bar!!"
        }

        def t = new Test1()

        assertEquals "bar!!", t.doStuff()
        assertEquals "foo", t.invokeMe()
    }

    void testInterfaceMethodInheritance() {
        registry.removeMetaClass(List)
        registry.removeMetaClass(ArrayList)

        def metaClass = registry.getMetaClass(List)
        assertTrue(metaClass instanceof ExpandoMetaClass)

        metaClass.sizeDoubled = {-> delegate.size() * 2 }
        metaClass.isFull = {-> false }

        def list = new ArrayList()

        list << 1
        list << 2

        assertEquals 4, list.sizeDoubled()

        list = new ArrayList()

        assert !list.isFull()
        assert !list.full
    }

    void testExpandoCreationHandle() {
        def metaClass = registry.getMetaClass(URL)
        if (!(metaClass instanceof ExpandoMetaClass)) {
            registry.removeMetaClass(URL)
        }

        def url = new URL("http://grails.org")
        metaClass = registry.getMetaClass(url.getClass())
        assertTrue(metaClass instanceof ExpandoMetaClass)

        metaClass.toUpperString = {->
            delegate.toString().toUpperCase()
        }

        assertEquals "http://grails.org", url.toString()
        assertEquals "HTTP://GRAILS.ORG", url.toUpperString()
    }

    void testExpandoInheritance() {
        registry.removeMetaClass(String)

        def metaClass = registry.getMetaClass(Object)
        if (!(metaClass instanceof ExpandoMetaClass)) {
            registry.removeMetaClass(Object)
            metaClass = registry.getMetaClass(Object)
        }

        metaClass.toFoo = {-> "foo" }

        def uri = new URI("http://bar.com")
        def s = "bar"

        assertEquals "foo", uri.toFoo()
        assertEquals "foo", s.toFoo()

        metaClass.toBar = {-> "bar" }

        assertEquals "bar", uri.toBar()
        assertEquals "bar", s.toBar()
    }

    void testAddMethodToChildThenParent() {
        registry.removeMetaClass(Test1)
        registry.removeMetaClass(EMCInheritTest)

        EMCInheritTest.metaClass.foo = {-> "hello!" }

        def emc = new EMCInheritTest()

        assertEquals "hello!", emc.foo()

        Test1.metaClass.foo = {-> "uck" }
        emc = new EMCInheritTest()
        // make sure original foo wasn't overridden
        assertEquals "hello!", emc.foo()
    }

    void testAddMethodMissingToChildThenParent() {
        registry.removeMetaClass(Test1)
        registry.removeMetaClass(EMCInheritTest)
        registry.removeMetaClass(Foo)
        registry.removeMetaClass(IBar)
        registry.removeMetaClass(Object)

        EMCInheritTest.metaClass.methodMissing = {String name, args -> "hello!" }

        def emc = new EMCInheritTest()

        assertEquals "hello!", emc.foo()

        Test1.metaClass.methodMissing = {String name, args -> "uck" }
        emc = new EMCInheritTest()
        // make sure original foo wasn't overridden
        assertEquals "hello!", emc.bar()
    }
}

interface IBar {}

interface Foo extends IBar {

}

class Test1 implements Foo {
    String name = "Fred"

    def invokeMe() { "foo" }
}

class EMCInheritTest extends Test1 {

}

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