src/spec/test/metaprogramming/InterceptionThroughMetaClassTest.groovy

/*
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 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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,
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 *  "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
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 */
package metaprogramming

import groovy.xml.Entity
import org.junit.jupiter.api.Test

// tag::meta_class_interception[]
class InterceptionThroughMetaClassTest {

    @Test
    void testPOJOMetaClassInterception() {
        String invoking = 'ha'
        invoking.metaClass.invokeMethod = { String name, Object args ->
            'invoked'
        }

        assert invoking.length() == 'invoked'
        assert invoking.someMethod() == 'invoked'
    }

    @Test
    void testPOGOMetaClassInterception() {
        Entity entity = new Entity('Hello')
        entity.metaClass.invokeMethod = { String name, Object args ->
            'invoked'
        }

        assert entity.build(new Object()) == 'invoked'
        assert entity.someMethod() == 'invoked'
    }
}
// end::meta_class_interception[]