001/*
002 * Copyright 2015 SirWellington Tech.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package tech.sirwellington.alchemy.test.junit.runners;
018
019import java.lang.annotation.Retention;
020import java.lang.annotation.Target;
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.integers;
028import static tech.sirwellington.alchemy.generator.NumberGenerators.negativeIntegers;
029import static tech.sirwellington.alchemy.generator.NumberGenerators.positiveIntegers;
030import static tech.sirwellington.alchemy.test.Checks.Internal.checkNotNull;
031import static tech.sirwellington.alchemy.test.Checks.Internal.checkThat;
032import static tech.sirwellington.alchemy.test.junit.runners.GenerateInteger.Type.POSITIVE;
033import static tech.sirwellington.alchemy.test.junit.runners.GenerateInteger.Type.RANGE;
034
035/**
036 * Used in with the {@link AlchemyTestRunner}, this Annotations allows the 
037 * Runtime Injection of Generated Integers from the {@link AlchemyGenerator} library.
038 * 
039 * Example:
040 * <pre>
041 * {@code
042 * `@RunWith(AlchemyTestRunner.class)
043 * public class ExampleTest
044 * {
045 *   `@GenerateInteger(POSITIVE)
046 *    private int size;
047 * 
048 *    ...
049 * }
050 * }
051 * </pre>
052 * Note, ticks (`) used to escape Javadocs.
053 * 
054 * @see GenerateString
055 * @see GenerateLong
056 * @see GenerateDouble
057 * 
058 * @author SirWellington
059 */
060@Target(FIELD)
061@Retention(RUNTIME)
062public @interface GenerateInteger
063{
064
065    Type value() default POSITIVE;
066
067    int min() default 0;
068
069    int max() default 0;
070
071    public enum Type
072    {
073        POSITIVE,
074        NEGATIVE,
075        ANY,
076        RANGE;
077    }
078
079    @Internal
080    @NonInstantiable
081    class Values
082    {
083
084        private Values() throws IllegalAccessException
085        {
086            throw new IllegalAccessException("cannot instantiate");
087        }
088
089        static AlchemyGenerator<Integer> createGeneratorFor(GenerateInteger annotation)
090        {
091            checkNotNull(annotation, "missing annotation");
092
093            Type type = annotation.value();
094            checkNotNull(type, "@GenerateInteger missing value");
095
096            if (type == RANGE)
097            {
098                int min = annotation.min();
099                int max = annotation.max();
100                checkThat(min < max, "@GenerateInteger: min must be less than max");
101                return integers(min, max);
102            }
103
104            //Cover remaining cases
105            switch (type)
106            {
107                case POSITIVE:
108                    return positiveIntegers();
109                case NEGATIVE:
110                    return negativeIntegers();
111                default:
112                    return integers(Integer.MIN_VALUE, Integer.MAX_VALUE);
113            }
114        }
115
116    }
117
118}