Refactor probes, extracted out to a generic class

inspector-vc/src/main/java/org/oneedtech/inspect/vc/probe/ContextPropertyProbe.java

@@ -7,6 +7,7 @@ import static org.oneedtech.inspect.util.code.Defensives.checkNotNull;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.function.BiFunction;
 
 import org.oneedtech.inspect.core.probe.Probe;
 import org.oneedtech.inspect.core.probe.RunContext;
@@ -24,32 +25,29 @@ import com.google.common.collect.ImmutableMap;
  *
  * @author mgylling
  */
-public class ContextPropertyProbe extends Probe<JsonNode> {
+public class ContextPropertyProbe extends PropertyProbe {
 	private final VerifiableCredential.Type type;
 
 	public ContextPropertyProbe(VerifiableCredential.Type type) {
-		super(ID);
+		super(ID, "@context");
 		this.type = checkNotNull(type);
+		setValidations(this::validate);
 	}
 
 	@Override
-	public ReportItems run(JsonNode root, RunContext ctx) throws Exception {
+	protected ReportItems reportForNonExistentProperty(RunContext ctx) {
-
-		ArrayNode contextNode = (ArrayNode) root.get("@context");
-		if (contextNode == null) {
 		return notRun("No @context property", ctx);
 	}
 
+	public ReportItems validate(List<String> nodeValues, RunContext ctx) {
 		List<String> expected = values.get(values.keySet()
 				.stream()
 				.filter(s->s.contains(type))
 				.findFirst()
 				.orElseThrow(()-> new IllegalArgumentException(type.name() + " not recognized")));
-
-		List<String> given = JsonNodeUtil.asStringList(contextNode);
 		int pos = 0;
 		for (String uri : expected) {
-			if ((given.size() < pos + 1) || !given.get(pos).equals(uri)) {
+			if ((nodeValues.size() < pos + 1) || !nodeValues.get(pos).equals(uri)) {
 				return error("missing required @context uri " + uri + " at position " + (pos + 1), ctx);
 			}
 			pos++;

inspector-vc/src/main/java/org/oneedtech/inspect/vc/probe/PropertyProbe.java

@@ -0,0 +1,45 @@
+package org.oneedtech.inspect.vc.probe;
+
+import java.util.List;
+import java.util.function.BiFunction;
+import java.util.function.Function;
+import java.util.function.Predicate;
+
+import org.oneedtech.inspect.core.probe.Probe;
+import org.oneedtech.inspect.core.probe.RunContext;
+import org.oneedtech.inspect.core.report.ReportItems;
+import org.oneedtech.inspect.vc.util.JsonNodeUtil;
+
+import com.fasterxml.jackson.databind.JsonNode;
+
+public class PropertyProbe extends Probe<JsonNode> {
+    private final String propertyName;
+    private BiFunction<List<String>, RunContext, ReportItems> validations;
+
+    public PropertyProbe(String id, String propertyName) {
+        super(id);
+        this.propertyName = propertyName;
+        this.validations = this::defaultValidation;
+    }
+
+    public void setValidations(BiFunction<List<String>, RunContext, ReportItems> validations) {
+        this.validations = validations;
+    }
+
+    @Override
+    public ReportItems run(JsonNode root, RunContext ctx) throws Exception {
+        JsonNode propertyNode = root.get(propertyName);
+		if (propertyNode == null) {
+			return reportForNonExistentProperty(ctx);
+        }
+		List<String> values = JsonNodeUtil.asStringList(propertyNode);
+        return validations.apply(values, ctx);
+    }
+    protected ReportItems reportForNonExistentProperty(RunContext ctx) {
+        return fatal("No " + propertyName + " property", ctx);
+    }
+
+    private ReportItems defaultValidation(List<String> nodeValues, RunContext ctx) {
+        return notRun("Not additional validations run", ctx);
+    }
+}

inspector-vc/src/main/java/org/oneedtech/inspect/vc/probe/TypePropertyProbe.java

@@ -4,38 +4,25 @@ import static org.oneedtech.inspect.util.code.Defensives.checkNotNull;
 
 import java.util.List;
 
-import org.oneedtech.inspect.core.probe.Probe;
 import org.oneedtech.inspect.core.probe.RunContext;
 import org.oneedtech.inspect.core.report.ReportItems;
 import org.oneedtech.inspect.vc.VerifiableCredential;
-import org.oneedtech.inspect.vc.VerifiableCredential.Type;
-import org.oneedtech.inspect.vc.util.JsonNodeUtil;
-
-import com.fasterxml.jackson.databind.JsonNode;
-import com.fasterxml.jackson.databind.node.ArrayNode;
 
 /**
  * A Probe that verifies a credential's type property.
  *
  * @author mgylling
  */
-public class TypePropertyProbe extends Probe<JsonNode> {
+public class TypePropertyProbe extends PropertyProbe {
 	private final VerifiableCredential.Type expected;
 
 	public TypePropertyProbe(VerifiableCredential.Type expected) {
-		super(ID);
+		super(ID, "type");
 		this.expected = checkNotNull(expected);
+		this.setValidations(this::validate);
 	}
 
-	@Override
+	public ReportItems validate(List<String> values, RunContext ctx) {
-	public ReportItems run(JsonNode root, RunContext ctx) throws Exception {
-
-		ArrayNode typeNode = (ArrayNode) root.get("type");
-		if (typeNode == null)
-			return fatal("No type property", ctx);
-
-		List<String> values = JsonNodeUtil.asStringList(typeNode);
-
 		if (!values.contains("VerifiableCredential")) {
 			return fatal("The type property does not contain the entry 'VerifiableCredential'", ctx);
 		}