Handles edge cases of + and * the way jsonlogic.com does

When presented with an array parameter, jsonlogic.com uses the first
value for + and * expressions.

Author: magnarn

src/main/java/io/github/jamsesso/jsonlogic/evaluator/expressions/MathExpression.java

@@ -1,6 +1,7 @@
 package io.github.jamsesso.jsonlogic.evaluator.expressions;
 
 import io.github.jamsesso.jsonlogic.evaluator.JsonLogicEvaluationException;
+import io.github.jamsesso.jsonlogic.utils.ArrayLike;
 
 import java.util.List;
 import java.util.function.BiFunction;
@@ -45,6 +46,11 @@ public Object evaluate(List arguments, Object data, String jsonPath) throws Json
     for (int i = 0; i < arguments.size(); i++) {
       Object value = arguments.get(i);
 
+      if (key.equals("*") || key.equals("+")) {
+        while (ArrayLike.isEligible(value)) {
+          value = new ArrayLike(value).get(0);
+        }
+      }
       if (value instanceof String) {
         try {
           values[i] = Double.parseDouble((String) value);

src/test/java/io/github/jamsesso/jsonlogic/MathExpressionTests.java

@@ -32,6 +32,14 @@ public void testSingleAdd() throws JsonLogicException {
     assertEquals(3.14, result);
   }
 
+  @Test
+  public void testAddWithArray() throws JsonLogicException {
+    String json = "{\"+\":[2,[[3,4],5]]}";
+    Object result = jsonLogic.apply(json, null);
+
+    assertEquals(5.0, result);  // This matches reference impl at jsonlogic.com
+  }
+
   @Test
   public void testStringAdd() throws JsonLogicException {
     assertNull(jsonLogic.apply("{\"+\" : \"foo\"}", null));
@@ -79,6 +87,14 @@ public void testMultiMultiply() throws JsonLogicException {
     assertEquals(32.0, result);
   }
 
+  @Test
+  public void testMultiplyWithArray() throws JsonLogicException {
+    String json = "{\"*\":[2,[[3, 4], 5]]}";
+    Object result = jsonLogic.apply(json, null);
+
+    assertEquals(6.0, result);  // This matches reference impl at jsonlogic.com
+  }
+
   @Test
   public void testDivide() throws JsonLogicException {
     String json = "{\"/\":[4,2]}";