Incorporate code review feedback.

- Renames the rule to `QueueableWithoutFinalizer` to be more neutral.
- Provides a more robust description.
- Provides a more succinct error message.
- Provides a positive sample for the documentation .

pmd-apex/src/main/java/net/sourceforge/pmd/lang/apex/rule/bestpractices/QueueableWithoutFinalizerRule.java

@@ -18,7 +18,7 @@ import net.sourceforge.pmd.lang.apex.rule.AbstractApexRule;
  *
  * @author mitchspano
  */
-public class QueueableShouldAttachFinalizerRule extends AbstractApexRule {
+public class QueueableWithoutFinalizerRule extends AbstractApexRule {
 
   private static final String EXECUTE = "execute";
   private static final String QUEUEABLE = "queueable";

pmd-apex/src/main/resources/category/apex/bestpractices.xml

@@ -285,29 +285,54 @@ Detects when a local variable is declared and/or assigned but not used.
         </example>
     </rule>
 
-    <rule name="QueueableShouldAttachFinalizer"
+    <rule name="QueueableWithoutFinalizer"
           since="7.8.0"
           language="apex"
-          message="It is best practice to call the `System.attachFinalizer(Finalizer f)` method within the `execute` method of a class which implements the `Queueable` interface."
-          class="net.sourceforge.pmd.lang.apex.rule.bestpractices.QueueableShouldAttachFinalizerRule"
-          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_apex_bestpractices.html#queueableshouldattachfinalizer">
+          message="This Queueable doesn't attach a Finalizer"
+          class="net.sourceforge.pmd.lang.apex.rule.bestpractices.QueueableWithoutFinalizerRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_apex_bestpractices.html#queueablewithoutfinalizer">
         <description>
 Detects when the Queueable interface is used but a Finalizer is not attached.
+It is best practice to call the `System.attachFinalizer(Finalizer f)` method within the `execute` method of a class which implements the `Queueable` interface.
+Without attaching a Finalizer, there is no way of designing error recovery actions should the Queueable action fail.
         </description>
         <priority>5</priority>
         <example>
 <![CDATA[
-    public class UserUpdater implements Queueable {
-        public List<User> usersToUpdate;
+// Incorrect code, does not attach a finalizer.
+public class UserUpdater implements Queueable {
+    public List<User> usersToUpdate;
 
-        public UserUpdater(List<User> usersToUpdate) {
-            this.usersToUpdate = usersToUpdate;
-        }
+    public UserUpdater(List<User> usersToUpdate) {
+        this.usersToUpdate = usersToUpdate;
+    }
 
-        public void execute(QueueableContext context) { // no Finalizer is attached
-            update usersToUpdate;
+    public void execute(QueueableContext context) { // no Finalizer is attached
+        update usersToUpdate;
+    }
+}
+
+// Proper code, attaches a finalizer.
+public class UserUpdater implements Queueable, Finalizer {
+    public List<User> usersToUpdate;
+
+    public UserUpdater(List<User> usersToUpdate) {
+        this.usersToUpdate = usersToUpdate;
+    }
+
+    public void execute(QueueableContext context) {
+        System.attachFinalizer(this);
+        update usersToUpdate;
+    }
+
+    public void execute(FinalizerContext ctx) {
+        if (ctx.getResult() == ParentJobResult.SUCCESS) {
+            // Handle success
+        } else {
+            // Handle failure
         }
     }
+}
 ]]>
         </example>
     </rule>

pmd-apex/src/test/java/net/sourceforge/pmd/lang/apex/rule/bestpractices/QueueableWithoutFinalizerTest.java

@@ -6,6 +6,6 @@ package net.sourceforge.pmd.lang.apex.rule.bestpractices;
 
 import net.sourceforge.pmd.test.PmdRuleTst;
 
-class QueueableShouldAttachFinalizerTest extends PmdRuleTst {
+class QueueableWithoutFinalizerTest extends PmdRuleTst {
   // no additional unit tests
 }

pmd-apex/src/test/resources/net/sourceforge/pmd/lang/apex/rule/bestpractices/xml/QueueableWithoutFinalizer.xml

@@ -5,7 +5,7 @@
     xsi:schemaLocation="http://pmd.sourceforge.net/rule-tests http://pmd.sourceforge.net/rule-tests_1_0_0.xsd">
 
     <test-code>
-        <description>[apex] Queueable Should Attach Finalizer - positive test case #5302</description>
+        <description>[apex] Queueable Without Finalizer - positive test case #5302</description>
         <expected-problems>1</expected-problems>
         <expected-linenumbers>8</expected-linenumbers>
         <code><![CDATA[
@@ -23,7 +23,7 @@ public class UserUpdater implements Queueable {
         ]]></code>
     </test-code>
     <test-code>
-        <description>[apex] Queueable Should Attach Finalizer - negative test case #5302</description>
+        <description>[apex] Queueable Without Finalizer - negative test case #5302</description>
         <expected-problems>0</expected-problems>
         <code><![CDATA[
 public class UserUpdater implements Queueable, Finalizer {