rewrite xpath rule and add some test cases

pmd-javascript/src/main/resources/category/ecmascript/codestyle.xml

@@ -222,21 +222,17 @@ be misleading.  Considering removing this unnecessary Block.
         <priority>3</priority>
         <properties>
             <property name="xpath">
-                <value>
-<![CDATA[
-//(Block|Scope)
-    [not(
-        parent::FunctionNode or
-        parent::IfStatement or
-        parent::ForLoop or
-        parent::ForInLoop or
-        parent::WhileLoop or
-        parent::DoLoop or
-        parent::TryStatement or
-        parent::CatchClause 
-    )]
-]]>
-                </value>
+                <value><![CDATA[
+                    //Scope[
+                        count(ancestor::*) = 1
+                        and not(preceding::EmptyStatement)
+                    ]
+                    | //SwitchCase[./Scope]
+                    | //(Scope|Block)[
+                        ./(Scope|Block)
+                        and count(./*) = 1
+                    ]
+                ]]></value>
             </property>
         </properties>
         <example>

pmd-javascript/src/test/resources/net/sourceforge/pmd/lang/ecmascript/rule/codestyle/xml/UnnecessaryBlock.xml

@@ -174,13 +174,18 @@ do {
 
     <test-code>
         <description>Bad, switch</description>
-        <expected-problems>1</expected-problems>
+        <expected-problems>2</expected-problems>
         <code><![CDATA[
 switch(1) {
     case 1:
         {
         }
         break;
+    case 2:
+        {
+            1 + 2;
+        }
+        return;
 }
         ]]></code>
     </test-code>
@@ -241,4 +246,14 @@ let a, b, a1, b1, c, d, rest, pop, push;
 function fn( ({arg}) ){ return arg}
         ]]></code>
     </test-code>
+    <test-code>
+        <description>not using semicolons case</description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+import { foo } from './someScript.js' // missing semicolon
+const { isLoggedIn } = useAuth();  // <--- violation here: unnecessary block
+import { foo2 } from './someScript2.js'; 
+const { isLoggedIn2 } = useAuth2()  //
+        ]]></code>
+    </test-code>
 </test-data>