fix list get when precise true

Author: DQinYuan

src/main/java/com/alibaba/qlexpress4/runtime/MemberResolver.java

@@ -20,6 +20,8 @@ public enum MatchPriority {
         MISMATCH(-1),
         // e.g. Integer -> Number
         EXTEND(0),
+        // e.g. BigDecimal -> int
+        NUMBER_DEMOTION(9),
         // e.g. int -> long
         // 1 -> 8
         NUMBER_PROMOTION(8),
@@ -227,8 +229,9 @@ private static int resolveArgPriority(Class<?> paramType, Class<?> argType) {
 
         Integer paramNumLevel = BasicUtil.numberPromoteLevel(paramType);
         Integer argNumLevel = BasicUtil.numberPromoteLevel(argType);
-        if (paramNumLevel != null && argNumLevel != null && paramNumLevel >= argNumLevel) {
-            return MatchPriority.NUMBER_PROMOTION.priority + argNumLevel - paramNumLevel;
+        if (paramNumLevel != null && argNumLevel != null) {
+            return paramNumLevel >= argNumLevel ? MatchPriority.NUMBER_PROMOTION.priority + argNumLevel - paramNumLevel
+                : MatchPriority.NUMBER_DEMOTION.priority;
         }
 
         // Handle primitive to Object boxing conversion

src/test/java/com/alibaba/qlexpress4/Express4RunnerTest.java

@@ -1251,6 +1251,20 @@ public void customSelectorWhenNoCloseTest() {
         assertErrorCode(express4Runner, "'Hello ' + ${pl}", QLErrorCodes.SYNTAX_ERROR.name());
     }
 
+    @Test
+    public void listGetWhenPreciseTest() {
+        InitOptions initOptions = InitOptions.builder().securityStrategy(QLSecurityStrategy.open()).build();
+        Express4Runner runner = new Express4Runner(initOptions);
+        QLOptions qlOptions = QLOptions.builder().precise(true).cache(true).build();
+        Map<String, Object> context = new HashMap<>();
+        ArrayList<String> list = new ArrayList<>();
+        list.add("a");
+        list.add("b");
+        context.put("list", list);
+        QLResult result = runner.execute("list.get(list.size()-1);", context, qlOptions);
+        assertEquals("b", result.getResult());
+    }
+    
     private void assertResultEquals(Express4Runner express4Runner, String script, Object expect) {
         assertResultPredicate(express4Runner, script, result -> Objects.equals(expect, result));
     }