Add unit test for id, name and description being null.

smart-connector/src/main/java/eu/knowledge/engine/smartconnector/impl/SmartConnectorBuilder.java

@@ -16,7 +16,30 @@ public SmartConnector create() {
 	}
 
 	public static SmartConnectorBuilder newSmartConnector(KnowledgeBase knowledgeBase) {
+
+		checkNull(knowledgeBase);
+
 		return new SmartConnectorBuilder(knowledgeBase);
 	}
 
+	private static void checkNull(KnowledgeBase knowledgeBase) {
+		String message = "The KB ";
+		boolean allNonNull = true;
+		if (knowledgeBase.getKnowledgeBaseId() == null) {
+			allNonNull = false;
+			message += "id";
+		} else if (knowledgeBase.getKnowledgeBaseName() == null) {
+			allNonNull = false;
+			message += "name";
+		} else if (knowledgeBase.getKnowledgeBaseDescription() == null) {
+			allNonNull = false;
+			message += "description";
+		}
+
+		message += " should be non-null.";
+
+		if (!allNonNull)
+			throw new NullPointerException(message);
+	}
+
 }

smart-connector/src/test/java/eu/knowledge/engine/smartconnector/api/KnowledgeBaseNullTest.java

@@ -0,0 +1,105 @@
+package eu.knowledge.engine.smartconnector.api;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.net.URI;
+
+import org.junit.jupiter.api.Test;
+
+import eu.knowledge.engine.smartconnector.impl.SmartConnectorBuilder;
+
+/**
+ * Giving null values for id, name or description is incorrect and this unit
+ * tests makes sure we throw a null pointer exception when constructing the SC.
+ */
+class KnowledgeBaseNullTest {
+
+	private MyKnowledgeBase kb = new MyKnowledgeBase("kb1");
+
+	private static class MyKnowledgeBase implements KnowledgeBase {
+
+		private String id;
+		private String name;
+		private String desc;
+		private boolean idIsNull = false;
+		private boolean nameIsNull = false;
+		private boolean descIsNull = false;
+
+		public MyKnowledgeBase(String aName) {
+			this.id = "https://www.example.org/" + aName;
+			this.name = aName;
+			this.desc = aName + " description";
+		}
+
+		@Override
+		public URI getKnowledgeBaseId() {
+			if (idIsNull)
+				return null;
+			else
+				return URI.create(this.id);
+		}
+
+		@Override
+		public String getKnowledgeBaseName() {
+			if (nameIsNull)
+				return null;
+			else
+				return this.name;
+		}
+
+		@Override
+		public String getKnowledgeBaseDescription() {
+			if (descIsNull)
+				return null;
+			else
+				return this.desc;
+		}
+
+		@Override
+		public void smartConnectorReady(SmartConnector aSC) {
+		}
+
+		@Override
+		public void smartConnectorConnectionLost(SmartConnector aSC) {
+		}
+
+		@Override
+		public void smartConnectorConnectionRestored(SmartConnector aSC) {
+		}
+
+		@Override
+		public void smartConnectorStopped(SmartConnector aSC) {
+		}
+
+		public void setNull(boolean anIdIsNull, boolean aNameIsNull, boolean aDescIsNull) {
+			this.idIsNull = anIdIsNull;
+			this.nameIsNull = aNameIsNull;
+			this.descIsNull = aDescIsNull;
+		}
+	}
+
+	@Test
+	void testNullId() {
+		kb.setNull(true, false, false);
+		assertThrows(NullPointerException.class, () -> {
+			SmartConnectorBuilder.newSmartConnector(kb).create();
+		});
+	}
+
+	@Test
+	void testNullName() {
+		kb.setNull(false, true, false);
+		assertThrows(NullPointerException.class, () -> {
+			SmartConnectorBuilder.newSmartConnector(kb).create();
+		});
+	}
+
+	@Test
+	void testNullDesc() {
+		kb.setNull(false, false, true);
+		assertThrows(NullPointerException.class, () -> {
+			SmartConnectorBuilder.newSmartConnector(kb).create();
+		});
+	}
+
+}