Add missing test

maintenancewindows/resolver/resolver_test.go

@@ -0,0 +1,25 @@
+package resolver
+
+import (
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGetMaintenancePolicyPool(t *testing.T) {
+	err := os.Setenv(policyPathENV, "./testdata")
+	assert.NoError(t, err)
+
+	pool, err := GetMaintenancePolicyPool()
+	assert.NoError(t, err)
+
+	assert.Equal(t, 2, len(pool))
+	assert.Contains(t, pool, "ruleset-1.json")
+	assert.Contains(t, pool, "ruleset-2.json")
+
+	data1 := pool["ruleset-1.json"]
+	data2 := pool["ruleset-2.json"]
+	assert.NotNil(t, data1)
+	assert.NotNil(t, data2)
+}