adding tests for random pkg

internal/pkg/random/random_test.go

@@ -0,0 +1,28 @@
+package random
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGet(t *testing.T) {
+	var rands []string
+	// use case: for 1 000 concurrent
+	// requests (which is a big Gotenberg instance),
+	// none should have the identifier.
+	for i := 0; i < 1000; i++ {
+		rands = append(rands, Get())
+	}
+	unique := func() bool {
+		for i, rand := range rands {
+			for j, current := range rands {
+				if i != j && rand == current {
+					return false
+				}
+			}
+		}
+		return true
+	}
+	assert.Equal(t, true, unique())
+}