chore: add a test for the downloadFile method

Author: mdelapenya

e2e/go.mod

@@ -11,6 +11,7 @@ require (
 	github.com/onsi/ginkgo v1.10.1 // indirect
 	github.com/onsi/gomega v1.7.0 // indirect
 	github.com/sirupsen/logrus v1.4.2
+	github.com/stretchr/testify v1.5.1
 )
 
 replace github.com/testcontainers/testcontainers-go v0.0.8 => github.com/mdelapenya/testcontainers-go v0.0.9-compose-1

e2e/utils_test.go

@@ -0,0 +1,25 @@
+package e2e
+
+import (
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDownloadFile(t *testing.T) {
+	configurationFileURL := "https://raw.githubusercontent.com/elastic/beats/v7.6.0/metricbeat/metricbeat.yml"
+
+	configurationFilePath, err := downloadFile(configurationFileURL)
+	if err != nil {
+		t.Fail()
+	}
+
+	info, err := os.Stat(configurationFilePath)
+	if os.IsNotExist(err) {
+		t.Fail()
+	}
+
+	assert.False(t, info.IsDir())
+	assert.Equal(t, "metricbeat.yml", info.Name())
+}