fix: return empty list when name does not exist in getRoles function.

Author: shy1st

examples/rbac_with_hierarchy_policy_without_role.csv

@@ -0,0 +1,6 @@
+p, alice, data1, read
+p, bob, data2, write
+p, data1_admin, data1, read
+p, data1_admin, data1, write
+p, data2_admin, data2, read
+p, data2_admin, data2, write

src/main/java/org/casbin/jcasbin/rbac/DefaultRoleManager.java

@@ -14,12 +14,7 @@
 
 package org.casbin.jcasbin.rbac;
 
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
+import java.util.*;
 import java.util.function.BiPredicate;
 
 import org.casbin.jcasbin.util.Util;
@@ -53,7 +48,7 @@ public DefaultRoleManager(int maxHierarchyLevel) {
      * e.loadPolicy();
      * </pre>
      *
-     * 
+     *
      * @param maxHierarchyLevel the maximized allowed RBAC hierarchy level.
      * @param matchingFunc a matcher for supporting pattern in g
      * @param domainMatchingFunc a matcher for supporting domain pattern in g
@@ -216,7 +211,8 @@ public List<String> getRoles(String name, String... domain) {
         final DomainRoles allRoles = getMatchingDomainRoles(domain);
 
         if (!allRoles.hasRole(name, matchingFunc)) {
-            throw new IllegalArgumentException("error: name does not exist");
+            Util.logPrintfError("error: name does not exist");
+            return Collections.emptyList();
         }
 
         return allRoles.createRole(name, matchingFunc).getRoles();

src/test/java/org/casbin/jcasbin/main/SyncedRbacAPIUnitTest.java

@@ -16,6 +16,8 @@
 
 import org.junit.Test;
 
+import java.util.Collections;
+
 import static java.util.Arrays.asList;
 import static org.casbin.jcasbin.main.TestUtil.*;
 import static org.junit.Assert.assertEquals;
@@ -153,4 +155,14 @@ public void testImplicitPermissionAPI() {
         );
 
     }
+
+    @Test
+    public void testImplicitPermissionWithoutRoleAPI() {
+        Enforcer e = new SyncedEnforcer("examples/rbac_model.conf", "examples/rbac_with_hierarchy_policy_without_role.csv");
+        assertEquals(
+            e.getImplicitPermissionsForUser("alice"),
+            Collections.singletonList(asList("alice", "data1", "read"))
+        );
+
+    }
 }