001/*
002 * Copyright © 2018. Sir Wellington.
003 * Licensed under the Apache License, Version 2.0 (the "License");
004 * you may not use this file except in compliance with the License.
005 *
006 * You may obtain a copy of the License at
007 *     http://www.apache.org/licenses/LICENSE-2.0
008 *
009 * Unless required by applicable law or agreed to in writing, software
010 * distributed under the License is distributed on an "AS IS" BASIS,
011 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012 * See the License for the specific language governing permissions and
013 * limitations under the License.
014 */
015
016package tech.sirwellington.alchemy.test.junit.runners;
017
018import java.lang.annotation.Retention;
019import java.lang.annotation.Target;
020
021import tech.sirwellington.alchemy.annotations.access.Internal;
022import tech.sirwellington.alchemy.annotations.access.NonInstantiable;
023import tech.sirwellington.alchemy.generator.AlchemyGenerator;
024
025import static java.lang.annotation.ElementType.FIELD;
026import static java.lang.annotation.RetentionPolicy.RUNTIME;
027import static tech.sirwellington.alchemy.generator.NumberGenerators.*;
028import static tech.sirwellington.alchemy.test.Checks.Internal.checkNotNull;
029import static tech.sirwellington.alchemy.test.Checks.Internal.checkThat;
030import static tech.sirwellington.alchemy.test.junit.runners.GenerateInteger.Type.POSITIVE;
031import static tech.sirwellington.alchemy.test.junit.runners.GenerateInteger.Type.RANGE;
032
033/**
034 * Used in with the {@link AlchemyTestRunner}, this Annotations allows the
035 * Runtime Injection of Generated Integers from the {@link AlchemyGenerator} library.
036 * <p>
037 * Example:
038 * <pre>
039 * {@code
040 * `@RunWith(AlchemyTestRunner.class)
041 * public class ExampleTest
042 * {
043 *   `@GenerateInteger(POSITIVE)
044 *    private int size;
045 *
046 *    ...
047 * }
048 * }
049 * </pre>
050 * Note, ticks (`) used to escape Javadocs.
051 *
052 * @author SirWellington
053 * @see GenerateString
054 * @see GenerateLong
055 * @see GenerateDouble
056 */
057@Target(FIELD)
058@Retention(RUNTIME)
059public @interface GenerateInteger
060{
061
062    Type value() default POSITIVE;
063
064    int min() default 0;
065
066    int max() default 0;
067
068    public enum Type
069    {
070        POSITIVE,
071        NEGATIVE,
072        ANY,
073        RANGE;
074    }
075
076    @Internal
077    @NonInstantiable
078    class Values
079    {
080
081        private Values() throws IllegalAccessException
082        {
083            throw new IllegalAccessException("cannot instantiate");
084        }
085
086        static AlchemyGenerator<Integer> createGeneratorFor(GenerateInteger annotation)
087        {
088            checkNotNull(annotation, "missing annotation");
089
090            Type type = annotation.value();
091            checkNotNull(type, "@GenerateInteger missing value");
092
093            if (type == RANGE)
094            {
095                int min = annotation.min();
096                int max = annotation.max();
097                checkThat(min < max, "@GenerateInteger: min must be less than max");
098                return integers(min, max);
099            }
100
101            //Cover remaining cases
102            switch (type)
103            {
104                case POSITIVE:
105                    return positiveIntegers();
106                case NEGATIVE:
107                    return negativeIntegers();
108                default:
109                    return integers(Integer.MIN_VALUE, Integer.MAX_VALUE);
110            }
111        }
112
113    }
114
115}