Better error messages on illegal input

4 files changed, 18 insertions, 14 deletions

diff --git a/document/src/main/java/com/yahoo/document/json/readers/ArrayReader.java b/document/src/main/java/com/yahoo/document/json/readers/ArrayReader.java
index 824a3073515..43dfa371361 100644
--- a/document/src/main/java/com/yahoo/document/json/readers/ArrayReader.java
+++ b/document/src/main/java/com/yahoo/document/json/readers/ArrayReader.java
@@ -14,6 +14,7 @@ import static com.yahoo.document.json.readers.JsonParserHelpers.expectArrayStart
 import static com.yahoo.document.json.readers.SingleValueReader.readSingleValue;
 
 public class ArrayReader {
+
     public static void fillArrayUpdate(TokenBuffer buffer, int initNesting, DataType valueType, List<FieldValue> arrayContents) {
         while (buffer.nesting() >= initNesting) {
             Preconditions.checkArgument(buffer.currentToken() != JsonToken.VALUE_NULL, "Illegal null value for array entry");
@@ -33,4 +34,5 @@ public class ArrayReader {
             buffer.next();
         }
     }
+
 }
diff --git a/document/src/main/java/com/yahoo/document/json/readers/CompositeReader.java b/document/src/main/java/com/yahoo/document/json/readers/CompositeReader.java
index e8b3e514cb2..2808e98149f 100644
--- a/document/src/main/java/com/yahoo/document/json/readers/CompositeReader.java
+++ b/document/src/main/java/com/yahoo/document/json/readers/CompositeReader.java
@@ -6,6 +6,7 @@ import com.yahoo.document.DataType;
 import com.yahoo.document.datatypes.CollectionFieldValue;
 import com.yahoo.document.datatypes.FieldValue;
 import com.yahoo.document.datatypes.MapFieldValue;
+import com.yahoo.document.datatypes.StringFieldValue;
 import com.yahoo.document.datatypes.StructuredFieldValue;
 import com.yahoo.document.datatypes.TensorFieldValue;
 import com.yahoo.document.datatypes.WeightedSet;
@@ -39,9 +40,8 @@ public class CompositeReader {
         } else if (fieldValue instanceof TensorFieldValue) {
             TensorReader.fillTensor(buffer, (TensorFieldValue) fieldValue);
         } else {
-            throw new IllegalStateException("Has created a composite field"
-                    + " value the reader does not know how to handle: "
-                    + fieldValue.getClass().getName() + " This is a bug. token = " + token);
+            throw new IllegalArgumentException("Expected a " + fieldValue.getClass().getName() + " but got an " +
+                                               (token == JsonToken.START_OBJECT ? "object" : "array" ));
         }
         expectCompositeEnd(buffer.currentToken());
     }
diff --git a/document/src/main/java/com/yahoo/document/json/readers/SingleValueReader.java b/document/src/main/java/com/yahoo/document/json/readers/SingleValueReader.java
index 5881267c252..f7bb5aecf0b 100644
--- a/document/src/main/java/com/yahoo/document/json/readers/SingleValueReader.java
+++ b/document/src/main/java/com/yahoo/document/json/readers/SingleValueReader.java
@@ -75,7 +75,7 @@ public class SingleValueReader {
                 update = ValueUpdate.createDivide(Double.valueOf(buffer.currentText()));
                 break;
             default:
-                throw new IllegalArgumentException("Operation \"" + buffer.currentName() + "\" not implemented.");
+                throw new IllegalArgumentException("Operation '" + buffer.currentName() + "' not implemented.");
         }
         return update;
     }
diff --git a/document/src/main/java/com/yahoo/document/json/readers/VespaJsonDocumentReader.java b/document/src/main/java/com/yahoo/document/json/readers/VespaJsonDocumentReader.java
index e252e71407a..7e32a6b8b44 100644
--- a/document/src/main/java/com/yahoo/document/json/readers/VespaJsonDocumentReader.java
+++ b/document/src/main/java/com/yahoo/document/json/readers/VespaJsonDocumentReader.java
@@ -100,13 +100,17 @@ public class VespaJsonDocumentReader {
             expectObjectStart(buffer.currentToken());
 
             String fieldName = buffer.currentName();
-            if (isFieldPath(fieldName)) {
-                addFieldPathUpdates(update, buffer, fieldName);
-            } else {
-                addFieldUpdates(update, buffer, fieldName);
+            try {
+                if (isFieldPath(fieldName)) {
+                    addFieldPathUpdates(update, buffer, fieldName);
+                } else {
+                    addFieldUpdates(update, buffer, fieldName);
+                }
+                expectObjectEnd(buffer.currentToken());
+            }
+            catch (IllegalArgumentException | IndexOutOfBoundsException e) {
+                throw new IllegalArgumentException("Error in '" + fieldName + "'", e);
             }
-
-            expectObjectEnd(buffer.currentToken());
             buffer.next();
         }
     }
@@ -177,16 +181,14 @@ public class VespaJsonDocumentReader {
 
     private AssignFieldPathUpdate readAssignFieldPathUpdate(DocumentType documentType, String fieldPath, TokenBuffer buffer) {
         AssignFieldPathUpdate fieldPathUpdate = new AssignFieldPathUpdate(documentType, fieldPath);
-        FieldValue fv = SingleValueReader.readSingleValue(
-                buffer, fieldPathUpdate.getFieldPath().getResultingDataType());
+        FieldValue fv = SingleValueReader.readSingleValue(buffer, fieldPathUpdate.getFieldPath().getResultingDataType());
         fieldPathUpdate.setNewValue(fv);
         return fieldPathUpdate;
     }
 
     private AddFieldPathUpdate readAddFieldPathUpdate(DocumentType documentType, String fieldPath, TokenBuffer buffer) {
         AddFieldPathUpdate fieldPathUpdate = new AddFieldPathUpdate(documentType, fieldPath);
-        FieldValue fv = SingleValueReader.readSingleValue(
-                buffer, fieldPathUpdate.getFieldPath().getResultingDataType());
+        FieldValue fv = SingleValueReader.readSingleValue(buffer, fieldPathUpdate.getFieldPath().getResultingDataType());
         fieldPathUpdate.setNewValues((Array) fv);
         return fieldPathUpdate;
     }