Add support for Wikidata single best value constraint

extensions/wikidata/src/org/openrefine/wikidata/qa/ConstraintFetcher.java

@@ -105,6 +105,11 @@ public interface ConstraintFetcher {
      */
     boolean hasSingleValue(PropertyIdValue pid);
     
+    /**
+     * Is this property expected to have a single best value only?
+     */
+    boolean hasSingleBestValue(PropertyIdValue pid);
+
     /**
      * Is this property expected to have distinct values?
      */

extensions/wikidata/src/org/openrefine/wikidata/qa/WikidataConstraintFetcher.java

@@ -79,6 +79,7 @@ public class WikidataConstraintFetcher implements ConstraintFetcher {
     public static String DISALLOWED_VALUES_CONSTRAINT_PID = "P2305";
 
     public static String SINGLE_VALUE_CONSTRAINT_QID = "Q19474404";
+    public static String SINGLE_BEST_VALUE_CONSTRAINT_QID = "Q52060874";
     public static String DISTINCT_VALUES_CONSTRAINT_QID = "Q21502410";
     
     public static String NO_BOUNDS_CONSTRAINT_QID = "Q51723761";
@@ -165,6 +166,11 @@ public class WikidataConstraintFetcher implements ConstraintFetcher {
         return getSingleConstraint(pid, SINGLE_VALUE_CONSTRAINT_QID) != null;
     }
     
+    @Override
+    public boolean hasSingleBestValue(PropertyIdValue pid) {
+        return getSingleConstraint(pid, SINGLE_BEST_VALUE_CONSTRAINT_QID) != null;
+    }
+
     @Override
     public boolean hasDistinctValues(PropertyIdValue pid) {
         return getSingleConstraint(pid, DISTINCT_VALUES_CONSTRAINT_QID) != null;

extensions/wikidata/src/org/openrefine/wikidata/qa/scrutinizers/SingleValueScrutinizer.java

@@ -35,6 +35,9 @@ import org.wikidata.wdtk.datamodel.interfaces.Statement;
  * For now this scrutinizer only checks for uniqueness at the item level (it
  * ignores qualifiers and references).
  * 
+ * Given that all ranks are currently set to Normal, this also checks for
+ * single best values.
+ * 
  * @author Antonin Delpeuch
  *
  */
@@ -54,7 +57,7 @@ public class SingleValueScrutinizer extends EditScrutinizer {
                 issue.setProperty("property_entity", pid);
                 issue.setProperty("example_entity", update.getItemId());
                 addIssue(issue);
-            } else if (_fetcher.hasSingleValue(pid)) {
+            } else if (_fetcher.hasSingleValue(pid) || _fetcher.hasSingleBestValue(pid)) {
                 seenSingleProperties.add(pid);
             }
         }

extensions/wikidata/tests/src/org/openrefine/wikidata/qa/MockConstraintFetcher.java

@@ -104,6 +104,11 @@ public class MockConstraintFetcher implements ConstraintFetcher {
         return true;
     }
     
+    @Override
+    public boolean hasSingleBestValue(PropertyIdValue pid) {
+        return false;
+    }
+
     @Override
     public boolean hasDistinctValues(PropertyIdValue pid) {
         return true;