Add test for RdfWriter

write/src/test/java/de/atextor/owlcli/write/RdfWriterTest.java

@@ -0,0 +1,106 @@
+/*
+ * This file is part of OWL-CLI.
+ * The contents of this file are subject to the LGPL License, Version 3.0.
+ * Copyright (c) 2020, Andreas Textor.
+ *
+ * This program is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General
+ * Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option)
+ * any later version.
+ * This program 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 this program.  If not, see http://www
+ * .gnu.org/licenses/.
+ */
+
+package de.atextor.owlcli.write;
+
+import io.vavr.control.Try;
+import org.apache.jena.rdf.model.Model;
+import org.apache.jena.rdf.model.ModelFactory;
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.InputStream;
+import java.io.StringReader;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class RdfWriterTest {
+    private final RdfWriter writer = new RdfWriter();
+
+    private InputStream turtleInputStream() {
+        final String turtleDocument = """
+            @prefix : <http://test.de#> .
+            @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
+
+            :Person a rdfs:Class .
+            :name a rdfs:Property .
+            :address a rdfs:Property .
+            :city a rdfs:Property .
+            :Max a :Person ;
+                :name "Max" ;
+                :address [
+                    :city "City Z"
+                ] .
+            """;
+        return new ByteArrayInputStream( turtleDocument.getBytes() );
+    }
+
+    private boolean canBeParsedAs( final String document, final String format, final int expectedNumberOfStatements ) {
+        final Model model = ModelFactory.createDefaultModel();
+        try {
+            model.read( new StringReader( document ), "", format );
+        } catch ( final Throwable t ) {
+            return false;
+        }
+        return model.listStatements().toList().size() == expectedNumberOfStatements;
+    }
+
+    @Test
+    public void testWriteTurtle() {
+        final Configuration configuration = Configuration.builder()
+            .inputFormat( Configuration.Format.TURTLE )
+            .outputFormat( Configuration.Format.TURTLE ).build();
+
+        final ByteArrayOutputStream out = new ByteArrayOutputStream();
+        final Try<Void> result = writer.write( turtleInputStream(), out, configuration );
+
+        assertThat( result ).hasSize( 1 );
+        assertThat( canBeParsedAs( out.toString(), "TURTLE", 8 ) ).isTrue();
+        assertThat( canBeParsedAs( out.toString(), "N-TRIPLE", 8 ) ).isFalse();
+        assertThat( canBeParsedAs( out.toString(), "RDF/XML", 8 ) ).isFalse();
+    }
+
+    @Test
+    public void testWriteNTriples() {
+        final Configuration configuration = Configuration.builder()
+            .inputFormat( Configuration.Format.TURTLE )
+            .outputFormat( Configuration.Format.NTRIPLE ).build();
+
+        final ByteArrayOutputStream out = new ByteArrayOutputStream();
+        final Try<Void> result = writer.write( turtleInputStream(), out, configuration );
+
+        assertThat( result ).hasSize( 1 );
+        // N-TRIPLES is also valid Turtle
+        assertThat( canBeParsedAs( out.toString(), "TURTLE", 8 ) ).isTrue();
+        assertThat( canBeParsedAs( out.toString(), "N-TRIPLE", 8 ) ).isTrue();
+        assertThat( canBeParsedAs( out.toString(), "RDF/XML", 8 ) ).isFalse();
+    }
+
+    @Test
+    public void testWriteRdfXml() {
+        final Configuration configuration = Configuration.builder()
+            .inputFormat( Configuration.Format.TURTLE )
+            .outputFormat( Configuration.Format.RDFXML ).build();
+
+        final ByteArrayOutputStream out = new ByteArrayOutputStream();
+        final Try<Void> result = writer.write( turtleInputStream(), out, configuration );
+
+        assertThat( result ).hasSize( 1 );
+        assertThat( canBeParsedAs( out.toString(), "TURTLE", 8 ) ).isFalse();
+        assertThat( canBeParsedAs( out.toString(), "N-TRIPLE", 8 ) ).isFalse();
+        assertThat( canBeParsedAs( out.toString(), "RDF/XML", 8 ) ).isTrue();
+    }
+}