From 56b29f53425ffa2d38fc7a36ceee3c6b25657402 Mon Sep 17 00:00:00 2001
From: Yeser Amer <yeser.amer@ibm.com>
Date: Fri, 21 Jun 2024 12:38:19 +0200
Subject: [PATCH] Fix

---
 .../runtime/functions/BaseFEELFunction.java   | 53 +++++++++++++------
 .../org/kie/dmn/feel/util/CoerceUtil.java     |  5 +-
 .../runtime/functions/ConcatFunction.java     |  5 +-
 3 files changed, 42 insertions(+), 21 deletions(-)

diff --git a/kie-dmn/kie-dmn-feel/src/main/java/org/kie/dmn/feel/runtime/functions/BaseFEELFunction.java b/kie-dmn/kie-dmn-feel/src/main/java/org/kie/dmn/feel/runtime/functions/BaseFEELFunction.java
index 7dcb0a5b26a..c9ea46a7148 100644
--- a/kie-dmn/kie-dmn-feel/src/main/java/org/kie/dmn/feel/runtime/functions/BaseFEELFunction.java
+++ b/kie-dmn/kie-dmn-feel/src/main/java/org/kie/dmn/feel/runtime/functions/BaseFEELFunction.java
@@ -62,6 +62,22 @@ public BaseFEELFunction(String name) {
         this.symbol = new FunctionSymbol( name, this );
     }
 
+    private enum CandidateParametersStatus {
+        PERFECT_MATCH(true),
+        COERCED(true),
+        MISSING(false);
+
+        private final boolean found;
+
+        CandidateParametersStatus(boolean found) {
+            this.found = found;
+        }
+
+        public boolean isFound() {
+            return found;
+        }
+    }
+
     @Override
     public String getName() {
         return name;
@@ -178,7 +194,7 @@ private Object[] rearrangeParameters(Object[] params, List<String> pnames) {
     }
 
     private CandidateMethod getCandidateMethod(EvaluationContext ctx, Object[] params, boolean isNamedParams, List<String> available) {
-        CandidateMethod candidate = null;
+        CandidateMethod candidateMethod = null;
         // first, look for exact matches
         for ( Method m : getClass().getDeclaredMethods() ) {
             if ( !Modifier.isPublic(m.getModifiers()) || !m.getName().equals( "invoke" ) ) {
@@ -225,7 +241,7 @@ private CandidateMethod getCandidateMethod(EvaluationContext ctx, Object[] param
                 continue;
             }
 
-            boolean found = true;
+            CandidateParametersStatus candidateParameterStatus = CandidateParametersStatus.PERFECT_MATCH;
             for ( int i = 0; i < parameterTypes.length; i++ ) {
                 Class<?> currentIdxActualParameterType = cm.getActualClasses()[i];
                 Class<?> expectedParameterType = parameterTypes[i];
@@ -233,35 +249,38 @@ private CandidateMethod getCandidateMethod(EvaluationContext ctx, Object[] param
                     Optional<Object[]> coercedParams = coerceParams(currentIdxActualParameterType, expectedParameterType, actualParams, i);
                     if (coercedParams.isPresent()) {
                         cm.setActualParams(coercedParams.get());
+                        candidateParameterStatus = CandidateParametersStatus.COERCED;
                         continue;
                     }
-                    found = false;
+                    candidateParameterStatus = CandidateParametersStatus.MISSING;
                     break;
                 }
             }
-            if ( found ) {
+            if ( candidateParameterStatus.isFound() ) {
                 cm.setApply( m );
-                if (candidate == null) {
-                    candidate = cm;
+                if (candidateMethod == null) {
+                    candidateMethod = cm;
+                } else if (candidateParameterStatus == CandidateParametersStatus.PERFECT_MATCH) {
+                    candidateMethod = cm;
+                    break;
                 } else {
-                    if (cm.getScore() > candidate.getScore()) {
-                        candidate = cm;
-                    } else if (cm.getScore() == candidate.getScore()) {
-                        if (isNamedParams && nullCount(cm.actualParams)<nullCount(candidate.actualParams)) {
-                            candidate = cm; // `cm` narrower for named parameters without need of passing nulls.
-                        } else if (candidate.getApply().getParameterTypes().length == 1
+                    if (cm.getScore() > candidateMethod.getScore()) {
+                        candidateMethod = cm;
+                    } else if (cm.getScore() == candidateMethod.getScore()) {
+                        if (isNamedParams && nullCount(cm.actualParams)<nullCount(candidateMethod.actualParams)) {
+                            candidateMethod = cm; // `cm` narrower for named parameters without need of passing nulls.
+                        } else if (candidateMethod.getApply().getParameterTypes().length == 1
                                 && cm.getApply().getParameterTypes().length == 1
-                                && candidate.getApply().getParameterTypes()[0].equals(Object.class)
+                                && candidateMethod.getApply().getParameterTypes()[0].equals(Object.class)
                                 && !cm.getApply().getParameterTypes()[0].equals(Object.class)) {
-                            candidate = cm; // `cm` is more narrowed, hence reflect `candidate` to be now `cm`.
+                            candidateMethod = cm; // `cm` is more narrowed, hence reflect `candidateMethod` to be now `cm`.
                         }
-                    } else {
-                        // do nothing.
                     }
                 }
             }
         }
-        return candidate;
+
+        return candidateMethod;
     }
     
     private static long nullCount(Object[] params) {
diff --git a/kie-dmn/kie-dmn-feel/src/main/java/org/kie/dmn/feel/util/CoerceUtil.java b/kie-dmn/kie-dmn-feel/src/main/java/org/kie/dmn/feel/util/CoerceUtil.java
index 60c27701320..c3cba6dcfdb 100644
--- a/kie-dmn/kie-dmn-feel/src/main/java/org/kie/dmn/feel/util/CoerceUtil.java
+++ b/kie-dmn/kie-dmn-feel/src/main/java/org/kie/dmn/feel/util/CoerceUtil.java
@@ -20,7 +20,6 @@
 
 import java.time.LocalDate;
 import java.time.ZonedDateTime;
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 import java.util.Optional;
@@ -73,7 +72,9 @@ static Optional<Object> coerceParam(Class<?> currentIdxActualParameterType, Clas
            singleton list. */
         if (!Collection.class.isAssignableFrom(currentIdxActualParameterType) &&
                 Collection.class.isAssignableFrom(expectedParameterType)) {
-            return Optional.of(new ArrayList<>(List.of(actualObject)));
+            Object singletonValue = coerceParam(currentIdxActualParameterType, currentIdxActualParameterType, actualObject)
+                    .orElse(actualObject);
+            return Optional.of(List.of(singletonValue));
         }
         if (actualObject instanceof LocalDate localDate &&
                 ZonedDateTime.class.isAssignableFrom(expectedParameterType)) {
diff --git a/kie-dmn/kie-dmn-signavio/src/main/java/org/kie/dmn/signavio/feel/runtime/functions/ConcatFunction.java b/kie-dmn/kie-dmn-signavio/src/main/java/org/kie/dmn/signavio/feel/runtime/functions/ConcatFunction.java
index 602c2b12ccd..26ccfc62252 100644
--- a/kie-dmn/kie-dmn-signavio/src/main/java/org/kie/dmn/signavio/feel/runtime/functions/ConcatFunction.java
+++ b/kie-dmn/kie-dmn-signavio/src/main/java/org/kie/dmn/signavio/feel/runtime/functions/ConcatFunction.java
@@ -20,6 +20,7 @@
 
 import java.util.Arrays;
 import java.util.List;
+import java.util.Objects;
 
 import org.kie.dmn.api.feel.runtime.events.FEELEvent;
 import org.kie.dmn.feel.runtime.events.InvalidParametersEvent;
@@ -39,10 +40,10 @@ public FEELFnResult<String> invoke(@ParameterName("values") List<?> list) {
 		if (list == null) {
 			return FEELFnResult.ofError(new InvalidParametersEvent(FEELEvent.Severity.ERROR, "list", "cannot be null"));
 		}
-		if (list.contains(null)) {
+		if (list.stream().anyMatch(Objects::isNull)) {
 			return FEELFnResult.ofError(new InvalidParametersEvent(FEELEvent.Severity.ERROR, "list", "cannot contain null values"));
 		}
-		
+
 		StringBuilder sb = new StringBuilder();
 		for (Object element : list) {
 			if (!(element instanceof String)) {