NIFI-22: fixed issues with newly added join and count functions

commons/nifi-expression-language/src/main/java/org/apache/nifi/attribute/expression/language/Query.java

@@ -116,6 +116,7 @@ import org.antlr.runtime.ANTLRStringStream;
 import org.antlr.runtime.CharStream;
 import org.antlr.runtime.CommonTokenStream;
 import org.antlr.runtime.tree.Tree;
+import org.apache.nifi.attribute.expression.language.evaluation.selection.MappingEvaluator;
 
 /**
  * Class used for creating and evaluating NiFi Expression Language. Once a Query
@@ -559,7 +560,6 @@ public class Query {
         }
     }
 
-    
     private static void verifyMappingEvaluatorReduced(final Evaluator<?> evaluator) {
         // if the result type of the evaluator is BOOLEAN, then it will always
         // be reduced when evaluator.
@@ -572,16 +572,16 @@ public class Query {
         if (rootEvaluator != null && rootEvaluator instanceof MultiAttributeEvaluator) {
             final MultiAttributeEvaluator multiAttrEval = (MultiAttributeEvaluator) rootEvaluator;
             switch (multiAttrEval.getEvaluationType()) {
-            case ALL_ATTRIBUTES:
+                case ALL_ATTRIBUTES:
-            case ALL_MATCHING_ATTRIBUTES:
+                case ALL_MATCHING_ATTRIBUTES:
-            case ALL_DELINEATED_VALUES: {
+                case ALL_DELINEATED_VALUES: {
-                if (!(evaluator instanceof ReduceEvaluator)) {
+                    if (!(evaluator instanceof ReduceEvaluator)) {
-                    throw new AttributeExpressionLanguageParsingException("Cannot evaluate expression because it attempts to reference multiple attributes but does not use a reducing function");
+                        throw new AttributeExpressionLanguageParsingException("Cannot evaluate expression because it attempts to reference multiple attributes but does not use a reducing function");
+                    }
+                    break;
                 }
-                break;
+                default:
-            }
+                    throw new AttributeExpressionLanguageParsingException("Cannot evaluate expression because it attempts to reference multiple attributes but does not use a reducing function");
-            default:
-                throw new AttributeExpressionLanguageParsingException("Cannot evaluate expression because it attempts to reference multiple attributes but does not use a reducing function");
             }
         }
     }
@@ -819,9 +819,17 @@ public class Query {
                         break;
                     case ALL_ATTRIBUTES:
                     case ALL_MATCHING_ATTRIBUTES:
-                    case ALL_DELINEATED_VALUES:
+                    case ALL_DELINEATED_VALUES: {
-                        chosenEvaluator = new AllAttributesEvaluator((BooleanEvaluator) evaluator, multiAttrEval);
+                        final ResultType resultType = evaluator.getResultType();
+                        if (resultType == ResultType.BOOLEAN) {
+                            chosenEvaluator = new AllAttributesEvaluator((BooleanEvaluator) evaluator, multiAttrEval);
+                        } else if (evaluator instanceof ReduceEvaluator) {
+                            chosenEvaluator = new MappingEvaluator((ReduceEvaluator) evaluator, multiAttrEval);
+                        } else {
+                            throw new AttributeExpressionLanguageException("Cannot evaluate Expression because it attempts to reference multiple attributes but does not use a reducing function");
+                        }
                         break;
+                    }
                 }
             }
         }

commons/nifi-expression-language/src/main/java/org/apache/nifi/attribute/expression/language/evaluation/reduce/JoinEvaluator.java

@@ -37,9 +37,9 @@ public class JoinEvaluator extends StringEvaluator implements ReduceEvaluator<St
     
     @Override
     public QueryResult<String> evaluate(final Map<String, String> attributes) {
-        final String subject = subjectEvaluator.evaluate(attributes).getValue();
+        String subject = subjectEvaluator.evaluate(attributes).getValue();
         if ( subject == null ) {
-            return new StringQueryResult("");
+            subject = "";
         }
         
         final String delimiter = delimiterEvaluator.evaluate(attributes).getValue();

commons/nifi-expression-language/src/main/java/org/apache/nifi/attribute/expression/language/evaluation/selection/MappingEvaluator.java

@@ -55,7 +55,7 @@ public class MappingEvaluator<T> implements Evaluator<T> {
 
     @Override
     public Evaluator<?> getSubjectEvaluator() {
-        return mappingEvaluator;
+        return null;
     }
 
 }

commons/nifi-expression-language/src/test/java/org/apache/nifi/attribute/expression/language/TestQuery.java

@@ -235,8 +235,8 @@ public class TestQuery {
     public void testJoin() {
         final Map<String, String> attributes = new HashMap<>();
         attributes.put("a.a", "a");
-        attributes.put("b.b", "b");
+        attributes.put("a.b", "b");
-        attributes.put("c.c", "c");
+        attributes.put("a.c", "c");
         verifyEquals("${allAttributes( 'a.a', 'a.b', 'a.c' ):join(', ')}", attributes, "a, b, c");
         verifyEquals("${x:join(', ')}", attributes, "");
         verifyEquals("${a.a:join(', ')}", attributes, "a");
@@ -282,7 +282,7 @@ public class TestQuery {
     public void testCount() {
         final Map<String, String> attributes = new HashMap<>();
         attributes.put("a", "a");
-        attributes.put("b", "");
+        attributes.put("b", "abc");
         attributes.put("c", "        \n");
         attributes.put("n1", "111");
         attributes.put("n2", "222");