fluent-job/fluent-job-api/src/test/java/org/apache/oozie/fluentjob/api/TestModifyOnce.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * 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, 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 org.apache.oozie.fluentjob.api;

import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;

import static org.junit.Assert.assertEquals;

public class TestModifyOnce {
    @Rule
    public final ExpectedException expectedException = ExpectedException.none();

    @Test
    public void testAllowOneModification() {
        final String defaultValue = "Default value";
        final ModifyOnce<String> instance = new ModifyOnce<>(defaultValue);

        assertEquals(defaultValue, instance.get());

        final String anotherValue = "Another value";
        instance.set(anotherValue);

        assertEquals(anotherValue, instance.get());
    }

    @Test
    public void testThrowOnSecondModification() {
        final ModifyOnce<String> instance = new ModifyOnce<>();
        instance.set("First modification");

        expectedException.expect(IllegalStateException.class);
        instance.set("Second modification");
    }
}