diff --git a/cdn.go b/cdn.go
index 5acf9b4..e5698ca 100644
--- a/cdn.go
+++ b/cdn.go
@@ -15,9 +15,11 @@ type BunnyCdn struct {
 	key string
 }
 
+var bunnyCdnUrl = "https://bunnycdn.com"
+
 func (cdn *BunnyCdn) Purge(url string) {
 	client := &http.Client{}
-	req, _ := http.NewRequest("POST", "https://bunnycdn.com/api/purge?url="+url, nil)
+	req, _ := http.NewRequest("POST", bunnyCdnUrl+"/api/purge?url="+url, nil)
 	req.Header.Add("Content-Type", "application/json")
 	req.Header.Add("Accept", "application/json")
 	req.Header.Add("AccessKey", cdn.key)
diff --git a/cdn_test.go b/cdn_test.go
new file mode 100644
index 0000000..8255d17
--- /dev/null
+++ b/cdn_test.go
@@ -0,0 +1,30 @@
+package main
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestBunnyCdn_Purge(t *testing.T) {
+	cdn := &BunnyCdn{
+		key: "testkey",
+	}
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if expectedUrl := "/api/purge?url=https://test.url/test"; r.URL.String() != expectedUrl {
+			t.Errorf("Wrong URL: Got %s, but expected %s", r.URL.String(), expectedUrl)
+		}
+		if expectedContentType := "application/json"; r.Header.Get("Content-Type") != expectedContentType {
+			t.Errorf("Wrong Content-Type Header: Got %s, but expected %s", r.Header.Get("Content-Type"), expectedContentType)
+		}
+		if expectedAccept := "application/json"; r.Header.Get("Accept") != expectedAccept {
+			t.Errorf("Wrong Accept Header: Got %s, but expected %s", r.Header.Get("Accept"), expectedAccept)
+		}
+		if r.Header.Get("AccessKey") != cdn.key {
+			t.Errorf("Wrong AccessKey Header: Got %s, but expected %s", r.Header.Get("AccessKey"), cdn.key)
+		}
+	}))
+	defer ts.Close()
+	bunnyCdnUrl = ts.URL
+	cdn.Purge("https://test.url/test")
+}
diff --git a/config.go b/config.go
index dc47399..4802cce 100644
--- a/config.go
+++ b/config.go
@@ -23,7 +23,7 @@ type SyndicationTarget struct {
 	Name string `json:"name"`
 }
 
-func init() {
+func initConfig() {
 	// Blog URL (required)
 	blogUrl, err := blogUrl()
 	if err != nil {
diff --git a/main.go b/main.go
index 1227427..3f935e8 100644
--- a/main.go
+++ b/main.go
@@ -8,6 +8,7 @@ import (
 )
 
 func main() {
+	initConfig()
 	log.Println("Starting micropub server...")
 	log.Println("Current time: " + time.Now().Format(time.RFC3339))
 	log.Println("Blog URL: " + BlogUrl)
diff --git a/validation_test.go b/validation_test.go
new file mode 100644
index 0000000..548292f
--- /dev/null
+++ b/validation_test.go
@@ -0,0 +1,25 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestGetContentType(t *testing.T) {
+	for key, value := range map[string]ContentType{
+		"":                                  UnsupportedType,
+		"test":                              UnsupportedType,
+		"application/x-www-form-urlencoded": WwwForm,
+		"application/json":                  Json,
+		"multipart/form-data":               Multipart,
+	} {
+		t.Run(key, func(t *testing.T) {
+			got, err := GetContentType(key)
+			if got != value {
+				t.Errorf("Wrong ContentType")
+			}
+			if value == UnsupportedType && err == nil {
+				t.Errorf("Error is nil")
+			}
+		})
+	}
+}
diff --git a/webmention_test.go b/webmention_test.go
new file mode 100644
index 0000000..495225b
--- /dev/null
+++ b/webmention_test.go
@@ -0,0 +1,34 @@
+package main
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+	"testing"
+)
+
+func Test_responseCodeForSource(t *testing.T) {
+	for _, code := range []int{200, 404} {
+		t.Run(strconv.Itoa(code), func(t *testing.T) {
+			ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				w.WriteHeader(code)
+			}))
+			defer ts.Close()
+			got, err := responseCodeForSource(ts.URL)
+			if err != nil || got != code {
+				t.Errorf("Wrong response code: Got %d, but expected %d", got, code)
+			}
+		})
+	}
+	t.Run("Error", func(t *testing.T) {
+		ts := httptest.NewUnstartedServer(nil)
+		defer ts.Close()
+		got, err := responseCodeForSource(ts.URL)
+		if err == nil {
+			t.Errorf("Error is nil")
+		}
+		if got != 0 {
+			t.Errorf("Wrong response code: Got %d, but expected %d", got, 0)
+		}
+	})
+}