diff --git a/dhp-workflows/dhp-graph-mapper/src/main/java/eu/dnetlib/dhp/oa/graph/raw/PatchRelationsApplication.java b/dhp-workflows/dhp-graph-mapper/src/main/java/eu/dnetlib/dhp/oa/graph/raw/PatchRelationsApplication.java
index c2bcf69f09..dddc53bc8e 100644
--- a/dhp-workflows/dhp-graph-mapper/src/main/java/eu/dnetlib/dhp/oa/graph/raw/PatchRelationsApplication.java
+++ b/dhp-workflows/dhp-graph-mapper/src/main/java/eu/dnetlib/dhp/oa/graph/raw/PatchRelationsApplication.java
@@ -79,6 +79,9 @@ public class PatchRelationsApplication {
         final Dataset<Relation> rels = Utils.readPath(spark, relationPath, Relation.class);
         final Dataset<RelationIdMapping> idMapping = Utils.readPath(spark, idMappingPath, RelationIdMapping.class);
 
+        log.info("relations: {}", rels.count());
+        log.info("idMapping: {}", idMapping.count());
+
         rels
                 .joinWith(idMapping, rels.col("source").equalTo(idMapping.col("oldId")), "left")
                 .map((MapFunction<Tuple2<Relation, RelationIdMapping>, Relation>) t -> {
diff --git a/dhp-workflows/dhp-graph-mapper/src/test/java/eu/dnetlib/dhp/oa/graph/raw/PatchRelationApplicationTest.java b/dhp-workflows/dhp-graph-mapper/src/test/java/eu/dnetlib/dhp/oa/graph/raw/PatchRelationApplicationTest.java
new file mode 100644
index 0000000000..def53c085e
--- /dev/null
+++ b/dhp-workflows/dhp-graph-mapper/src/test/java/eu/dnetlib/dhp/oa/graph/raw/PatchRelationApplicationTest.java
@@ -0,0 +1,89 @@
+package eu.dnetlib.dhp.oa.graph.raw;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.IOUtils;
+import org.apache.spark.SparkConf;
+import org.apache.spark.sql.SparkSession;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Optional;
+
+public class PatchRelationApplicationTest {
+
+    private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
+    public static final String ID_MAPPING_PATH = "map/id_mapping.json";
+
+    private static SparkSession spark;
+
+    private static Path workingDir;
+
+    private static final Logger log = LoggerFactory.getLogger(PatchRelationApplicationTest.class);
+
+    @BeforeAll
+    public static void beforeAll() throws IOException {
+        workingDir = Files
+                .createTempDirectory(PatchRelationApplicationTest.class.getSimpleName());
+        log.info("using work dir {}", workingDir);
+
+        SparkConf conf = new SparkConf();
+        conf.setAppName(PatchRelationApplicationTest.class.getSimpleName());
+
+        conf.setMaster("local[*]");
+        conf.set("spark.driver.host", "localhost");
+        conf.set("hive.metastore.local", "true");
+        conf.set("spark.ui.enabled", "false");
+        conf.set("spark.sql.warehouse.dir", workingDir.toString());
+        conf.set("hive.metastore.warehouse.dir", workingDir.resolve("warehouse").toString());
+
+        spark = SparkSession
+                .builder()
+                .appName(PatchRelationApplicationTest.class.getSimpleName())
+                .config(conf)
+                .getOrCreate();
+
+        FileUtils.copyInputStreamToFile(
+                PatchRelationApplicationTest.class.getResourceAsStream("id_mapping.json"),
+                workingDir.resolve(ID_MAPPING_PATH).toFile()
+        );
+
+        FileUtils.copyInputStreamToFile(
+                PatchRelationApplicationTest.class.getResourceAsStream("relations_to_patch.json"),
+                workingDir.resolve("graphBasePath/relation/rels.json").toFile()
+        );
+
+    }
+
+    @BeforeEach
+    public void setUp() throws IOException {
+
+
+    }
+
+    @AfterAll
+    public static void afterAll() throws IOException {
+        FileUtils.deleteDirectory(workingDir.toFile());
+        spark.stop();
+    }
+
+    @Test
+    public void testPatchRelationApplication() throws Exception {
+
+        PatchRelationsApplication.main(new String[] {
+                "-isSparkSessionManaged", Boolean.FALSE.toString(),
+                "-graphBasePath", workingDir.toString() + "/graphBasePath",
+                "-workingDir", workingDir.toString() + "/workingDir",
+                "-idMappingPath", workingDir.toString() + "/" + ID_MAPPING_PATH
+        });
+
+    }
+
+}
diff --git a/dhp-workflows/dhp-graph-mapper/src/test/resources/eu/dnetlib/dhp/oa/graph/raw/id_mapping.json b/dhp-workflows/dhp-graph-mapper/src/test/resources/eu/dnetlib/dhp/oa/graph/raw/id_mapping.json
new file mode 100644
index 0000000000..640d042b1d
--- /dev/null
+++ b/dhp-workflows/dhp-graph-mapper/src/test/resources/eu/dnetlib/dhp/oa/graph/raw/id_mapping.json
@@ -0,0 +1,5 @@
+{"oldId": "1a", "newId": "1b"}
+{"oldId": "2a", "newId": "2b"}
+{"oldId": "3a", "newId": "3b"}
+{"oldId": "4a", "newId": "4b"}
+{"oldId": "5a", "newId": "5b"}
\ No newline at end of file
diff --git a/dhp-workflows/dhp-graph-mapper/src/test/resources/eu/dnetlib/dhp/oa/graph/raw/relations_to_patch.json b/dhp-workflows/dhp-graph-mapper/src/test/resources/eu/dnetlib/dhp/oa/graph/raw/relations_to_patch.json
new file mode 100644
index 0000000000..3e1203b183
--- /dev/null
+++ b/dhp-workflows/dhp-graph-mapper/src/test/resources/eu/dnetlib/dhp/oa/graph/raw/relations_to_patch.json
@@ -0,0 +1,6 @@
+{"source":"1a","target":"10a","collectedfrom":[{"key":"10|driver______::bee53aa31dc2cbb538c10c2b65fa5824","value":"DOAJ-Articles","dataInfo":null}],"dataInfo":{"invisible":false,"inferred":false,"deletedbyinference":false,"trust":"0.900","inferenceprovenance":null,"provenanceaction":{"classid":"sysimport:crosswalk:entityregistry","classname":"sysimport:crosswalk:entityregistry","schemeid":"dnet:provenanceActions","schemename":"dnet:provenanceActions"}},"lastupdatetimestamp":1626336932282,"relType":"datasourceOrganization","subRelType":"provision","relClass":"provides","validated":false,"validationDate":null,"properties":[]}
+{"source":"10a","target":"1a","collectedfrom":[{"key":"10|driver______::bee53aa31dc2cbb538c10c2b65fa5824","value":"DOAJ-Articles","dataInfo":null}],"dataInfo":{"invisible":false,"inferred":false,"deletedbyinference":false,"trust":"0.900","inferenceprovenance":null,"provenanceaction":{"classid":"sysimport:crosswalk:entityregistry","classname":"sysimport:crosswalk:entityregistry","schemeid":"dnet:provenanceActions","schemename":"dnet:provenanceActions"}},"lastupdatetimestamp":1626336932282,"relType":"datasourceOrganization","subRelType":"provision","relClass":"provides","validated":false,"validationDate":null,"properties":[]}
+{"source":"2a","target":"20a","collectedfrom":[{"key":"10|driver______::bee53aa31dc2cbb538c10c2b65fa5824","value":"DOAJ-Articles","dataInfo":null}],"dataInfo":{"invisible":false,"inferred":false,"deletedbyinference":false,"trust":"0.900","inferenceprovenance":null,"provenanceaction":{"classid":"sysimport:crosswalk:entityregistry","classname":"sysimport:crosswalk:entityregistry","schemeid":"dnet:provenanceActions","schemename":"dnet:provenanceActions"}},"lastupdatetimestamp":1626336932282,"relType":"datasourceOrganization","subRelType":"provision","relClass":"provides","validated":false,"validationDate":null,"properties":[]}
+{"source":"20a","target":"2a","collectedfrom":[{"key":"10|driver______::bee53aa31dc2cbb538c10c2b65fa5824","value":"DOAJ-Articles","dataInfo":null}],"dataInfo":{"invisible":false,"inferred":false,"deletedbyinference":false,"trust":"0.900","inferenceprovenance":null,"provenanceaction":{"classid":"sysimport:crosswalk:entityregistry","classname":"sysimport:crosswalk:entityregistry","schemeid":"dnet:provenanceActions","schemename":"dnet:provenanceActions"}},"lastupdatetimestamp":1626336932282,"relType":"datasourceOrganization","subRelType":"provision","relClass":"provides","validated":false,"validationDate":null,"properties":[]}
+{"source":"15a","target":"25a","collectedfrom":[{"key":"10|driver______::bee53aa31dc2cbb538c10c2b65fa5824","value":"DOAJ-Articles","dataInfo":null}],"dataInfo":{"invisible":false,"inferred":false,"deletedbyinference":false,"trust":"0.900","inferenceprovenance":null,"provenanceaction":{"classid":"sysimport:crosswalk:entityregistry","classname":"sysimport:crosswalk:entityregistry","schemeid":"dnet:provenanceActions","schemename":"dnet:provenanceActions"}},"lastupdatetimestamp":1626336932282,"relType":"datasourceOrganization","subRelType":"provision","relClass":"provides","validated":false,"validationDate":null,"properties":[]}
+{"source":"25a","target":"15a","collectedfrom":[{"key":"10|driver______::bee53aa31dc2cbb538c10c2b65fa5824","value":"DOAJ-Articles","dataInfo":null}],"dataInfo":{"invisible":false,"inferred":false,"deletedbyinference":false,"trust":"0.900","inferenceprovenance":null,"provenanceaction":{"classid":"sysimport:crosswalk:entityregistry","classname":"sysimport:crosswalk:entityregistry","schemeid":"dnet:provenanceActions","schemename":"dnet:provenanceActions"}},"lastupdatetimestamp":1626336932282,"relType":"datasourceOrganization","subRelType":"provision","relClass":"provides","validated":false,"validationDate":null,"properties":[]}