RMLTests.java

/*
 * Copyright (c) 2019-2023 Cefriel.
 *
 * Licensed 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 com.cefriel.template;

import com.cefriel.template.io.Reader;
import com.cefriel.template.utils.RMLCompilerUtils;
import com.cefriel.template.utils.TemplateFunctions;
import com.cefriel.template.utils.Util;
import org.eclipse.rdf4j.model.Model;
import org.eclipse.rdf4j.model.impl.TreeModel;
import org.eclipse.rdf4j.model.util.Models;
import org.eclipse.rdf4j.rio.RDFFormat;
import org.eclipse.rdf4j.rio.RDFParser;
import org.eclipse.rdf4j.rio.Rio;
import org.eclipse.rdf4j.rio.helpers.StatementCollector;
import org.junit.jupiter.api.Test;

import java.io.StringReader;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.Map;

import static org.junit.jupiter.api.Assertions.assertThrows;

public class RMLTests {

    final static String FOLDER = "src/test/resources/rml/";
    private String resolvePath(String folder, String file) {
        return FOLDER + file;
    }

    @Test
    public void invalidRMLTest() throws Exception {
        String folder = "rml";
        Path rmlMappings = Paths.get(resolvePath(folder, "invalid-mapping.ttl"));
        assertThrows(RuntimeException.class, () -> Util.validateRML(rmlMappings, false));
    }

    @Test
    public void validRMLTest() throws Exception {

        String folder = "rml";
        String rmlMappings = resolvePath(folder, "mapping.ttl");

        String expectedOutput = Files.readString(Paths.get(resolvePath(folder, "output.nq")));

        Util.validateRML(Paths.get(rmlMappings), false);

        Reader compilerReader = TemplateFunctions.getRDFReaderFromFile(rmlMappings);
        Path rmlCompiler = Paths.get("rml/rml-compiler.vm");
        Path compiledTemplatePath = Paths.get(resolvePath(folder,"template.rml.vm"));

        Map<String,String> rmlMap = new HashMap<>();
        rmlMap.put("basePath", FOLDER);

        TemplateExecutor rmlTemplateExecutor = new TemplateExecutor(new RMLCompilerUtils(), false, false, true, new TemplateMap(rmlMap), null);
        TemplateExecutor templateExecutor = new TemplateExecutor(new TemplateFunctions(), false, false, false, null, null);
        rmlTemplateExecutor.executeMapping(compilerReader, rmlCompiler, compiledTemplatePath);
        String result = templateExecutor.executeMapping(compilerReader, compiledTemplatePath);
        Files.delete(compiledTemplatePath);

        Model resultModel = parseRDFString(result);
        Model expectedOutputModel = parseRDFString(expectedOutput);

        assert(Models.isomorphic(resultModel, expectedOutputModel));
    }

    private static Model parseRDFString(String rdfString) throws Exception {
        RDFParser rdfParser = Rio.createParser(RDFFormat.NQUADS);

        Model model = new TreeModel();
        rdfParser.setRDFHandler(new StatementCollector(model));
        rdfParser.parse(new StringReader(rdfString), "http://example.com/base/");
        return model;
    }

}