HBASE-30283 list_labels shell command should return readable labels (#8461) (#8477)

Signed-off-by: Peng Lu <lupeng@apache.org>

(cherry picked from commit 8e8190e)

Author: liuxiaocs7

hbase-shell/src/main/ruby/shell/commands/list_labels.rb

@@ -33,9 +33,13 @@ def help
 
       def command(regex = '.*')
         list = visibility_labels_admin.list_labels(regex)
+        labels = []
         list.each do |label|
-          formatter.row([org.apache.hadoop.hbase.util.Bytes.toStringBinary(label.toByteArray)])
+          label_string = org.apache.hadoop.hbase.util.Bytes.toStringBinary(label.toByteArray)
+          formatter.row([label_string])
+          labels << label_string
         end
+        labels
       end
     end
   end

hbase-shell/src/test/ruby/hbase/visibility_labels_admin_test_cluster.rb

@@ -86,5 +86,17 @@ def teardown
       assert_not_nil(res['x:a'])
     end
 
+    define_test "list_labels should return an Array of readable label Strings" do
+      label = 'TEST_LIST_LABELS'
+      command(:add_labels, label)
+      $TEST_CLUSTER.waitLabelAvailable(10000, label)
+
+      labels = command(:list_labels, 'TEST_.*')
+      assert_kind_of(Array, labels)
+      labels.each { |l| assert_kind_of(String, l) }
+      assert(labels.include?(label),
+             "list_labels should include the created label #{label}")
+    end
+
   end
 end