ParametersProcessorValidator.java

/**
 * Powerunit - A JDK1.8 test framework
 * Copyright (C) 2014 Mathieu Boretti.
 *
 * This file is part of Powerunit
 *
 * Powerunit is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Powerunit is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Powerunit. If not, see <http://www.gnu.org/licenses/>.
 */
package ch.powerunit.impl.validator;

import java.util.HashSet;
import java.util.Set;

import javax.annotation.processing.ProcessingEnvironment;
import javax.annotation.processing.RoundEnvironment;
import javax.lang.model.element.Element;
import javax.lang.model.element.ElementKind;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.Modifier;
import javax.lang.model.element.TypeElement;
import javax.lang.model.type.DeclaredType;
import javax.lang.model.type.TypeKind;
import javax.lang.model.type.TypeMirror;

import ch.powerunit.Parameters;
import ch.powerunit.TestDelegator;

public interface ParametersProcessorValidator extends ProcessValidator {
    default void parametersValidation(ProcessingEnvironment processingEnv,
            RoundEnvironment roundEnv) {
        Set<Element> exists = new HashSet<>();
        Set<? extends Element> elements = roundEnv
                .getElementsAnnotatedWith(Parameters.class);
        TypeElement stream = processingEnv.getElementUtils().getTypeElement(
                "java.util.stream.Stream");
        for (Element element : elements) {
            if (element.getKind() != ElementKind.METHOD) {
                error("@Parameters must prefix a method -- " + element
                        + " is not a method");
                continue;
            }
            Element parent = element.getEnclosingElement();
            if (exists.contains(parent)) {
                warn("Class "
                        + elementAsString(parent)
                        + "\n\t contains more than one @Parameters method\n\tOnly one @Parameters method is allowed for a test class");
            }
            exists.add(parent);
            ExecutableElement ee = (ExecutableElement) element;
            if (!ee.getModifiers().contains(Modifier.STATIC)) {
                warn("Method "
                        + elementAsString(element)
                        + "\n\tis prefixed with @Parameters and is not static\n\tThe parameters method must be static");
            }
            if (!ee.getModifiers().contains(Modifier.PUBLIC)) {
                warn("Method "
                        + elementAsString(element)
                        + "\n\tis prefixed with @Parameters and is not public\n\tThe parameters method must be public");
            }
            TypeMirror rt = ee.getReturnType();
            if (rt.getKind() != TypeKind.DECLARED) {
                warn("Method " + elementAsString(element)
                        + "\n\tis prefixed with @Parameters and return " + rt
                        + "\n\tThe parameters method must return " + stream);
            } else {
                DeclaredType dt = (DeclaredType) rt;
                if (!processingEnv.getTypeUtils().isSubtype(
                        dt.asElement().asType(), stream.asType())) {
                    warn("Method " + elementAsString(element)
                            + "\n\tis prefixed with @Parameters and return "
                            + dt.asElement().asType()
                            + "\n\tThe parameters method must return " + stream);
                }
            }
            if (!ee.getParameters().isEmpty()
                    && ee.getEnclosingElement().getAnnotation(
                            TestDelegator.class) == null) {
                warn("Method "
                        + elementAsString(element)
                        + "\n\tis prefixed with @Parameters and is not 0-args\n\tThe parameters method must be 0-args");
            }
            if (ee.getParameters().size() != 1
                    && ee.getEnclosingElement().getAnnotation(
                            TestDelegator.class) != null) {
                warn("Method "
                        + elementAsString(element)
                        + "\n\tis prefixed with @Parameters and is not 1-args\n\tThe parameters method must be 1-args when used with TestDelegator.");
            }
        }
    }
}