diff --git a/functions/ensure.pp b/functions/ensure.pp
new file mode 100644
index 0000000..d509a74
--- /dev/null
+++ b/functions/ensure.pp
@@ -0,0 +1,24 @@
+# @summary function to cast ensure parameter to resource specific value
+function stdlib::ensure(
+    Variant[Boolean, Enum['present', 'absent']]               $ensure,
+    Enum['directory', 'link', 'mounted', 'service', 'file'] $resource,
+) >> String {
+    $_ensure = $ensure ? {
+        Boolean => $ensure.bool2str('present', 'absent'),
+        default => $ensure,
+    }
+    case $resource {
+        'service': {
+            $_ensure ? {
+                'present' => 'running',
+                default   => 'stopped',
+            }
+        }
+        default: {
+            $_ensure ? {
+                'present' => $resource,
+                default   => $_ensure,
+            }
+        }
+    }
+}
diff --git a/spec/functions/stdlib_ensure_spec.rb b/spec/functions/stdlib_ensure_spec.rb
new file mode 100644
index 0000000..ebdcb9c
--- /dev/null
+++ b/spec/functions/stdlib_ensure_spec.rb
@@ -0,0 +1,18 @@
+require 'spec_helper'
+
+describe 'stdlib::ensure' do
+  context 'work with service resource' do
+    it { is_expected.to run.with_params('present', 'service').and_return('running') }
+    it { is_expected.to run.with_params(true, 'service').and_return('running') }
+    it { is_expected.to run.with_params('absent', 'service').and_return('stopped') }
+    it { is_expected.to run.with_params(false, 'service').and_return('stopped') }
+  end
+  ['directory', 'link', 'mounted', 'file'].each do |resource|
+    context "work with #{resource} resource" do
+      it { is_expected.to run.with_params('present', resource).and_return(resource) }
+      it { is_expected.to run.with_params(true, resource).and_return(resource) }
+      it { is_expected.to run.with_params('absent', resource).and_return('absent') }
+      it { is_expected.to run.with_params(false, resource).and_return('absent') }
+    end
+  end
+end