InstanceValidator: improve test, documentation, error message

Also rewrite a schema for a more simple example Signed-off-by: Francis Galiegue <fgaliegue@gmail.com>

Author: fge

src/main/java/com/github/fge/jsonschema/processors/validation/InstanceValidator.java

@@ -61,6 +61,26 @@ public final class InstanceValidator
  private final MessageBundle validationMessages;
  private final Processor<SchemaContext, ValidatorList> keywordBuilder;
 
+ /*
+ * It is possible to trigger a validation loop if there is a repeated
+ * triplet schema ID/schema pointer/instance pointer while we validate;
+ * example schema:
+ *
+ * { "oneOf": [ {}, { "$ref": "#" } ] }
+ *
+ * Whatever the data, validation will end up validating, for a same pointer
+ * into the instance, the following pointers into the schema:
+ *
+ * "" -> "/oneOf/0" -> "/oneOf/1" -> "" <-- LOOP
+ *
+ * This is not a JSON Reference loop here, but truly a validation loop.
+ *
+ * We therefore use this set to record the triplets seen by using an
+ * Equivalence over FullData which detects this. This is helped by the fact
+ * that SchemaTree now implements equals()/hashCode() in -core; since this
+ * class is instantiated for each instance validation, we are certain that
+ * what instance pointer is seen is the one of the instance we validate.
+ */
  private final Set<Equivalence.Wrapper<FullData>> visited
  = Sets.newLinkedHashSet();
 
@@ -88,7 +108,10 @@ public FullData process(final ProcessingReport report,
  final ProcessingMessage message = input.newMessage()
  .put("domain", "validation")
  .setMessage(errmsg)
- .put("visited", node);
+ .putArgument("alreadyVisited", toJson(input))
+ .putArgument("instancePointer",
+ input.getInstance().getPointer().toString())
+ .put("validationPath", node);
  throw new ProcessingException(message);
  }
 
@@ -231,15 +254,16 @@ public String toString()
  return "instance validator";
  }
 
- private static JsonNode toJson(final FullData data)
+ private static String toJson(final FullData data)
  {
  final SchemaTree tree = data.getSchema();
  final URI baseUri = tree.getLoadingRef().getLocator();
  try {
+ // TODO: there should be an easier way to do that...
  final URITemplate template = new URITemplate(baseUri + "{+ptr}");
  final VariableMap vars = VariableMap.newBuilder().addScalarValue(
  "ptr", tree.getPointer()).freeze();
- return JacksonUtils.nodeFactory().textNode(template.toString(vars));
+ return template.toString(vars);
  } catch (URITemplateException e) {
  throw new IllegalStateException("wtf??", e);
  }

src/main/resources/com/github/fge/jsonschema/validator/validation.properties

@@ -78,5 +78,4 @@ err.format.UUID.invalid = input string "%s" is not a valid UUID
 #
 # Other messages
 #
-err.common.validationLoop = validation loop: same schema visited more than \
- once for the same instance
+err.common.validationLoop = validation loop: schema "%s" visited twice for pointer "%s" into validated instance

src/test/java/com/github/fge/jsonschema/processors/validation/ValidationProcessorTest.java

@@ -26,10 +26,13 @@
 import com.github.fge.jackson.JacksonUtils;
 import com.github.fge.jackson.JsonLoader;
 import com.github.fge.jackson.NodeType;
+import com.github.fge.jackson.jsonpointer.JsonPointer;
+import com.github.fge.jackson.jsonpointer.JsonPointerException;
 import com.github.fge.jsonschema.cfg.ValidationConfiguration;
 import com.github.fge.jsonschema.core.exceptions.ProcessingException;
 import com.github.fge.jsonschema.core.keyword.syntax.checkers.SyntaxChecker;
 import com.github.fge.jsonschema.core.processing.Processor;
+import com.github.fge.jsonschema.core.report.ProcessingMessage;
 import com.github.fge.jsonschema.core.report.ProcessingReport;
 import com.github.fge.jsonschema.core.tree.CanonicalSchemaTree;
 import com.github.fge.jsonschema.core.tree.JsonTree;
@@ -49,8 +52,11 @@
 import org.testng.annotations.Test;
 
 import java.io.IOException;
+import java.net.URI;
+import java.util.Arrays;
 import java.util.concurrent.atomic.AtomicInteger;
 
+import static com.github.fge.jsonschema.matchers.ProcessingMessageAssert.assertMessage;
 import static org.mockito.Mockito.mock;
 import static org.testng.Assert.assertEquals;
 import static org.testng.Assert.assertTrue;
@@ -120,23 +126,30 @@ public void childrenAreExploredOnDemandEvenIfContainerFails()
 
  @Test(timeOut = 1000)
  public void circularReferencingDuringValidationIsDetected()
- throws IOException, ProcessingException
+ throws IOException, ProcessingException, JsonPointerException
  {
  final JsonNode schemaNode
  = JsonLoader.fromResource("/other/issue102.json");
  final JsonSchemaFactory factory = JsonSchemaFactory.byDefault();
  final JsonValidator validator = factory.getValidator();
  final MessageBundle bundle
  = MessageBundles.getBundle(JsonSchemaValidationBundle.class);
- final String expectedMsg
- = bundle.getMessage("err.common.validationLoop");
 
  try {
  validator.validate(schemaNode,
  JacksonUtils.nodeFactory().nullNode());
  fail("No exception thrown!");
  } catch (ProcessingException e) {
- assertEquals(e.getProcessingMessage().getMessage(), expectedMsg);
+ final URI uri = URI.create("#/oneOf/0");
+ final ProcessingMessage message = e.getProcessingMessage();
+ final String expectedMessage
+ = bundle.printf("err.common.validationLoop", uri, "");
+ assertMessage(message)
+ .hasMessage(expectedMessage)
+ .hasField("alreadyVisited", uri)
+ .hasField("instancePointer", JsonPointer.empty().toString())
+ .hasField("validationPath",
+ Arrays.asList("#", "#/oneOf/0", "#/oneOf/1"));
  }
  assertTrue(true);
  }

src/test/resources/other/issue102.json

@@ -1,30 +1 @@
-{
- "$schema": "http://json-schema.org/draft-04/schema#",
- "definitions": {
- "S": {
- "allOf": [
- {
- "type": "string",
- "enum": ["a"]
- },
- {
- "oneOf": [
- {
- "$ref": "#/definitions/S"
- },
- {
- "type": "string",
- "enum": [""]
- }
- ]
- },
- {
- "type": "string",
- "enum": ["b"]
- }
- ],
- "additionalItems": false
- }
- },
- "$ref": "#/definitions/S"
-}
+{ "oneOf": [ {}, { "$ref": "#" } ] }