core-it-support/core-it-plugins/maven-it-plugin-expression/src/test/java/org/apache/maven/plugin/coreit/ExpressionUtilTest.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.maven.plugin.coreit;

import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNull;
import static org.junit.jupiter.api.Assertions.assertSame;

/**
 * @author Benjamin Bentmann
 *
 */
public class ExpressionUtilTest {

    @Test
    public void testEvaluate() {
        Object array = new String[] {"one", "two", "three"};
        Object list = Arrays.asList("0", "-1", "-2");
        Object map = Collections.singletonMap("some.key", "value");
        Object bean = new BeanTwo();

        Map<String, Object> contexts = new HashMap<>();
        contexts.put("array", array);
        contexts.put("list", list);
        contexts.put("map", map);
        contexts.put("bean", bean);

        assertSame(array, evaluate("array", contexts));
        assertSame(array, ExpressionUtil.evaluate("array/", contexts).get("array"));
        assertSame(list, evaluate("list", contexts));
        assertSame(map, evaluate("map", contexts));
        assertSame(bean, evaluate("bean", contexts));
        assertNull(evaluate("no-root", contexts));

        assertEquals(3, evaluate("array/length", contexts));
        assertEquals("three", evaluate("array/2", contexts));
        assertEquals(5, evaluate("array/2/length", contexts));
        assertNull(evaluate("array/invalid", contexts));
        assertNull(evaluate("array/-1", contexts));
        assertNull(evaluate("array/999", contexts));
        assertEquals(3, ExpressionUtil.evaluate("array/*", contexts).size());
        assertEquals("one", ExpressionUtil.evaluate("array/*", contexts).get("array/0"));
        assertEquals("two", ExpressionUtil.evaluate("array/*", contexts).get("array/1"));
        assertEquals("three", ExpressionUtil.evaluate("array/*", contexts).get("array/2"));

        assertEquals(3, evaluate("list/size", contexts));
        assertEquals("-2", evaluate("list/2", contexts));
        assertNull(evaluate("list/invalid", contexts));
        assertNull(evaluate("list/-1", contexts));
        assertNull(evaluate("list/999", contexts));
        assertEquals(3, ExpressionUtil.evaluate("list/*", contexts).size());
        assertEquals("0", ExpressionUtil.evaluate("list/*", contexts).get("list/0"));
        assertEquals("-1", ExpressionUtil.evaluate("list/*", contexts).get("list/1"));
        assertEquals("-2", ExpressionUtil.evaluate("list/*", contexts).get("list/2"));

        assertEquals(1, evaluate("map/size", contexts));
        assertEquals("value", evaluate("map/some.key", contexts));
        assertNull(evaluate("map/invalid", contexts));

        assertEquals("field", evaluate("bean/field", contexts));
        assertNull(evaluate("bean/invalid", contexts));
        assertEquals("prop", evaluate("bean/bean/prop", contexts));
        assertEquals("flag", evaluate("bean/bean/flag", contexts));
        assertEquals("arg", evaluate("bean/bean/arg", contexts));
    }

    private static Object evaluate(String expression, Object context) {
        return ExpressionUtil.evaluate(expression, context).get(expression);
    }

    @Test
    public void testGetProperty() {
        BeanOne bean1 = new BeanOne();
        BeanTwo bean2 = new BeanTwo();

        assertEquals(bean1.isFlag(), ExpressionUtil.getProperty(bean1, "flag"));
        assertEquals(bean1.getProp(), ExpressionUtil.getProperty(bean1, "prop"));
        assertEquals(bean1.get("get"), ExpressionUtil.getProperty(bean1, "get"));

        assertNull(ExpressionUtil.getProperty(bean2, "invalid"));
        assertEquals(bean2.field, ExpressionUtil.getProperty(bean2, "field"));
        assertSame(bean2.bean, ExpressionUtil.getProperty(bean2, "bean"));

        assertEquals(0, ExpressionUtil.getProperty(new String[0], "length"));
    }

    public static class BeanOne {
        public String isFlag() {
            return "flag";
        }

        public String getProp() {
            return "prop";
        }

        public String get(String arg) {
            return arg;
        }
    }

    public static class BeanTwo {
        public String field = "field";

        public BeanOne bean = new BeanOne();
    }
}