jena-core/src/test/java/org/apache/jena/graph/test/AbstractTestReifier.java

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 * regarding copyright ownership.  The ASF licenses this file
 * to you 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
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 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
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 * See the License for the specific language governing permissions and
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package org.apache.jena.graph.test;

import org.apache.jena.graph.* ;
import org.apache.jena.rdf.model.impl.ReifierStd ;
import org.apache.jena.shared.AlreadyReifiedException ;
import org.apache.jena.shared.CannotReifyException ;
import org.apache.jena.vocabulary.RDF ;

/**
    Abstract base class for reification tests. 
 */
public abstract class AbstractTestReifier extends GraphTestBase
{
    protected static final Triple ALL = Triple.ANY;

    public AbstractTestReifier( String name )
    { super( name ); }

    public abstract Graph getGraph();

    protected final Graph getGraphWith( String facts )
    {
        Graph result = getGraph();
        graphAdd( result, facts );
        return result;
    }

    /**
        Answer the empty graph if cond is false, otherwise the graph with the given facts.
     */
    protected final Graph graphWithUnless( boolean cond, String facts )
    { return graphWith( cond ? "" : facts ); }

    protected final Graph graphWithIf( boolean cond, String facts )
    { return graphWithUnless( !cond, facts ); }

    public void testGetGraphNotNull()
    { assertNotNull( getGraph()  ); }

    /**
        Check that the standard reifier will note, but not hide, reification quads.
     */
    public void testStandard()
    {
        Graph g = getGraph( );
        assertFalse( ReifierStd.hasTriple(g, triple( "s p o" ) ) );
        g.add( NodeCreateUtils.createTriple( "x rdf:subject s" ) );
        assertEquals( 1, g.size() );
        g.add( NodeCreateUtils.createTriple( "x rdf:predicate p" ) );
        assertEquals( 2, g.size() );  
        g.add( NodeCreateUtils.createTriple( "x rdf:object o" ) );
        assertEquals( 3, g.size() );            
        g.add( NodeCreateUtils.createTriple( "x rdf:type rdf:Statement" ) );
        assertEquals( 4, g.size() );
        assertTrue( ReifierStd.hasTriple(g, triple( "s p o" ) ) );                      
    }

    /**
        Test that the Standard reifier will expose implicit quads arising from reifyAs().
     */
    public void testStandardExplode()
    {
        Graph g = getGraph( );
        ReifierStd.reifyAs( g, node( "a" ), triple( "p Q r" ) );
        Graph r = Factory.createDefaultGraph( );
        graphAdd( r, "a rdf:type rdf:Statement; a rdf:subject p; a rdf:predicate Q; a rdf:object r" );
        assertEquals( 4, g.size() );
        assertIsomorphic( r, g );
    }

    /**
         Ensure that over-specifying a reification means that we don't get a triple
         back. Goodness knows why this test wasn't in right from the beginning.
     */
    public void testOverspecificationSuppressesReification()
    {
        Graph g = getGraph();
        graphAdd( g, "x rdf:subject A; x rdf:predicate P; x rdf:object O; x rdf:type rdf:Statement" );
        assertEquals( triple( "A P O" ), ReifierStd.getTriple(g, node( "x" ) ) );
        graphAdd( g, "x rdf:subject BOOM" ); 
        assertEquals( null, ReifierStd.getTriple( g, node( "x" ) ) );
    }

    public void testReificationSubjectClash()
    {
        testReificationClash( "x rdf:subject SS" );
    }    

    public void testReificationPredicateClash()
    {
        testReificationClash( "x rdf:predicate PP" );
    }    

    public void testReificationObjectClash()
    {
        testReificationClash( "x rdf:object OO" );
    }

    protected void testReificationClash( String clashingStatement )
    {
        Graph g = getGraph();
        Triple SPO = NodeCreateUtils.createTriple( "S P O" );
        ReifierStd.reifyAs(g,  node( "x" ), SPO );
        assertTrue( ReifierStd.hasTriple( g , SPO ) );
        graphAdd( g,  clashingStatement );
        assertEquals( null, ReifierStd.getTriple( g , node( "x" ) ) );
        // System.err.println( ">> tRC: clashing = " + clashingStatement );
        assertFalse( ReifierStd.hasTriple(g, SPO ) );
    }

    /**
        Test that reifying a triple explicitly has some effect on the graph only for Standard
        reifiers.
     */
    public void testManifestQuads()
    {
        Graph g = getGraph();   
        ReifierStd.reifyAs(g, node( "A" ), triple( "S P O" ) ) ;
        String reified = "A rdf:type rdf:Statement; A rdf:subject S; A rdf:predicate P; A rdf:object O";
        assertIsomorphic( graphWith( reified ), g );
    }

    public void testHiddenVsReification()
    {
        Graph g = getGraph();
        ReifierStd.reifyAs( g, node( "A" ), triple( "S P O" ) );
        assertTrue( ReifierStd.findEither( g , ALL, false ).hasNext() );    
    }

    public void testRetrieveTriplesByNode()
    {
        Graph G = getGraph();
        Node N = NodeFactory.createBlankNode(), M = NodeFactory.createBlankNode();
        ReifierStd.reifyAs( G , N, triple( "x R y" ) );
        assertEquals( "gets correct triple", triple( "x R y" ), ReifierStd.getTriple( G , N ) );
        ReifierStd.reifyAs( G, M, triple( "p S q" ) );
        assertDiffer( "the anon nodes must be distinct", N, M );
        assertEquals( "gets correct triple", triple( "p S q" ), ReifierStd.getTriple( G , M ) );

        assertTrue( "node is known bound", ReifierStd.hasTriple( G, M ) );
        assertTrue( "node is known bound", ReifierStd.hasTriple( G, N ) );
        assertFalse( "node is known unbound", ReifierStd.hasTriple( G, NodeFactory.createURI( "any:thing" ) ) );
    }

    public void testRetrieveTriplesByTriple()
    {
        Graph G = getGraph();
        Triple T = triple( "x R y" ), T2 = triple( "y R x" );
        Node N = node( "someNode" );
        ReifierStd.reifyAs( G, N, T );
        assertTrue( "R must have T", ReifierStd.hasTriple( G, T ) );
        assertFalse( "R must not have T2", ReifierStd.hasTriple( G, T2 ) );
    }   

    public void testReifyAs()
    {
        Graph G = getGraph();
        Node X = NodeFactory.createURI( "some:uri" );
        assertEquals( "node used", X, ReifierStd.reifyAs( G, X, triple( "x R y" ) ) );
        assertEquals( "retrieves correctly", triple( "x R y" ), ReifierStd.getTriple( G, X ) );
    }

    public void testAllNodes()
    {
        Graph G = getGraph();
        ReifierStd.reifyAs( G, node("x"), triple( "cows eat grass" ) );
        ReifierStd.reifyAs( G, node("y"), triple( "pigs can fly" ) );
        ReifierStd.reifyAs( G, node("z"), triple( "dogs may bark" ) );
        assertEquals( "", nodeSet( "z y x" ), iteratorToSet( ReifierStd.allNodes(G) ) );
    }

    public void testRemoveByNode()
    {
        Graph G = getGraph();
        Node X = node( "x" ), Y = node( "y" );
        ReifierStd.reifyAs( G, X, triple( "x R a" ) );
        ReifierStd.reifyAs( G, Y, triple( "y R a" ) );
        ReifierStd.remove( G, X, triple( "x R a" ) );
        assertFalse( "triple X has gone", ReifierStd.hasTriple( G, X ) );
        assertEquals( "triple Y still there", triple( "y R a" ), ReifierStd.getTriple( G, Y ) );
    }

    public void testRemoveFromNothing()
    {
        Graph G = getGraph();
        G.delete( triple( "quint rdf:subject S" ) );
    }

    public void testException()
    {
        Graph G = getGraph();
        Node X = node( "x" );
        ReifierStd.reifyAs( G, X, triple( "x R y" ) );
        ReifierStd.reifyAs( G, X, triple( "x R y" ) );
        try { ReifierStd.reifyAs( G, X, triple( "x R z" ) ); fail( "did not detect already reified node" ); }
        catch (AlreadyReifiedException e) { }      
    }

    public void testKevinCaseA()
    {
        Graph G = getGraph();
        Node X = node( "x" ), a = node( "a" ), b = node( "b" ), c = node( "c" );
        G.add( Triple.create( X, RDF.Nodes.type, RDF.Nodes.Statement ) );
        ReifierStd.reifyAs( G, X, Triple.create( a, b, c ) ); 
    }

    public void testKevinCaseB()
    {
        Graph G = getGraph();
        Node X = node( "x" ), Y = node( "y" );
        Node a = node( "a" ), b = node( "b" ), c = node( "c" );
        G.add( Triple.create( X, RDF.Nodes.subject, Y ) );
        try
        {
            ReifierStd.reifyAs( G, X, Triple.create( a, b, c ) );
            fail( "X already has subject Y: cannot make it a" );
        }
        catch (CannotReifyException e)
        { pass(); }
    }

    public void testQuadRemove()
    {
        Graph g = getGraph();
        assertEquals( 0, g.size() );
        Triple s = NodeCreateUtils.createTriple( "x rdf:subject s" );
        Triple p = NodeCreateUtils.createTriple( "x rdf:predicate p" );
        Triple o = NodeCreateUtils.createTriple( "x rdf:object o" );
        Triple t = NodeCreateUtils.createTriple( "x rdf:type rdf:Statement");
        g.add(s); g.add(p); g.add(o); g.add(t);
        assertEquals( 4, g.size() );
        g.delete(s); g.delete(p); g.delete(o); g.delete(t);
        assertEquals( 0, g.size() );
    }

    public void testEmpty()
    {
        Graph g = getGraph();
        assertTrue( g.isEmpty() );
        graphAdd( g, "x rdf:type rdf:Statement" ); assertFalse( g.isEmpty() );
        graphAdd( g, "x rdf:subject Deconstruction" ); assertFalse( g.isEmpty() );
        graphAdd( g, "x rdf:predicate rdfs:subTypeOf" ); assertFalse( g.isEmpty() );
        graphAdd( g, "x rdf:object LiteraryCriticism" ); assertFalse( g.isEmpty() );
    }

    public void testReifierEmptyFind()
    {
        Graph g = getGraph();
        assertEquals( tripleSet( "" ), ReifierStd.findExposed( g , Triple.ANY ).toSet() );
    }

    public void testReifierFindSubject()
    { testReifierFind( "x rdf:subject S" ); }

    public void testReifierFindObject()
    { testReifierFind( "x rdf:object O" ); }

    public void testReifierFindPredicate()
    { testReifierFind( "x rdf:predicate P" ); }

    public void testReifierFindComplete()
    { testReifierFind( "x rdf:predicate P; x rdf:subject S; x rdf:object O; x rdf:type rdf:Statement" ); }

    public void testReifierFindFilter()
    { 
        Graph g = getGraph();
        graphAdd( g, "s rdf:subject S" );
        assertEquals( tripleSet( "" ), ReifierStd.findExposed( g, triple( "s otherPredicate S" ) ).toSet() );
    }

    protected void testReifierFind( String triples )
    { testReifierFind( triples, "?? ?? ??" ); }

    protected void testReifierFind( String triples, String pattern )
    {
        Graph g = getGraph();
        graphAdd( g, triples );
        assertEquals(  tripleSet( triples ), ReifierStd.findExposed( g, triple( pattern ) ).toSet() );
    }
}