SONARJAVA-1209 Do not raise issues when inizializer type is unknown

Author: mpaladin

java-checks/src/main/java/org/sonar/java/checks/PublicStaticMutableMembersCheck.java

@@ -168,7 +168,8 @@ static boolean isMutable(@Nullable ExpressionTree initializer, Type type) {
   }
 
   private static boolean isAcceptedTypeOrUnmodifiableMethodCall(MethodInvocationTree mit) {
-    return isAcceptedType(mit.symbolType(), ACCEPTED_TYPES) || UNMODIFIABLE_METHOD_CALLS.anyMatch(mit);
+    Type type = mit.symbolType();
+    return type.isUnknown() || isAcceptedType(type, ACCEPTED_TYPES) || UNMODIFIABLE_METHOD_CALLS.anyMatch(mit);
   }
 
   private static boolean isAcceptedType(Type type, Set<String> accepted) {

java-checks/src/test/files/checks/PublicStaticMutableMembersCheck.java

@@ -13,6 +13,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.EnumSet;
 
 public class A {
   public static String [] strings1 = {"first","second"};  // Noncompliant {{Make this member "protected".}}
@@ -80,10 +81,21 @@ public class A {
   public static final Map<String, String> immutableMapApache = org.apache.commons.collections4.map.UnmodifiableMap.unmodifiableMap(new HashMap<String, String>());
 
   public static final List noInitializer;
-  public static final List unknown = foo(); // Noncompliant
+  // we don't know the type of foo
+  public static final List unknown = foo();
 
   public static List emptyList = Arrays.asList();
   public void changeEmptyList() {
     emptyList = new ArrayList(); // Noncompliant {{Make member "emptyList" "protected".}}
   }
+
+  enum E {
+    A, B, C
+  }
+  // FALSE negative: no issues raised when initializer type is unknown
+  // in this case Collections.unmodifiableSet(EnumSet.of is unknown because of generics
+  public static final Set<E> set = Collections.unmodifiableSet(EnumSet.of(
+    E.A,
+    E.C
+  ));
 }

java-checks/src/test/java/org/sonar/java/checks/PublicStaticMutableMembersCheckTest.java

@@ -30,4 +30,3 @@ public void test() {
   }
 
 }
-