fix: improve url validation

client/client.go

@@ -2,7 +2,6 @@ package client
 
 import (
 	"errors"
-	"fmt"
 	"net/http"
 	"net/url"
 	"time"
@@ -40,6 +39,16 @@ var (
 	ErrInvalidServerURL = errors.New("invalid contentserver url provided")
 )
 
+func isValidUrl(str string) bool {
+    u, err := url.Parse(str)
+
+	if u.Scheme != "http" && u.Scheme != "https" {
+		return false
+	}
+	
+    return err == nil && u.Scheme != "" && u.Host != ""
+}
+
 // NewHTTPClient constructs a new client to talk to the contentserver.
 // It returns an error if the provided url is empty or invalid.
 func NewHTTPClient(server string) (c *Client, err error) {
@@ -48,8 +57,9 @@ func NewHTTPClient(server string) (c *Client, err error) {
 		return nil, ErrEmptyServerURL
 	}
 
-	if _, err = url.Parse(server); err != nil {
-		return nil, fmt.Errorf("%w: %s", ErrInvalidServerURL, err.Error())
+	// validate url
+	if !isValidUrl(server) {
+		return nil, ErrInvalidServerURL
 	}
 
 	return NewHTTPClientWithTransport(NewHTTPTransport(server, http.DefaultClient))

client/client_test.go

@@ -12,6 +12,7 @@ import (
 	"github.com/foomo/contentserver/repo/mock"
 	"github.com/foomo/contentserver/requests"
 	"github.com/foomo/contentserver/server"
+	"github.com/stretchr/testify/assert"
 )
 
 const pathContentserver = "/contentserver"
@@ -25,6 +26,28 @@ func init() {
 	SetupLogging(true, "contentserver_client_test.log")
 }
 
+func TestInvalidHTTPClientInit(t *testing.T) {
+	c, err := NewHTTPClient("")
+	assert.Nil(t, c)
+	assert.Error(t, err)
+
+	c, err = NewHTTPClient("bogus")
+	assert.Nil(t, c)
+	assert.Error(t, err)
+
+	c, err = NewHTTPClient("htt:/notaurl")
+	assert.Nil(t, c)
+	assert.Error(t, err)
+
+	c, err = NewHTTPClient("htts://notaurl")
+	assert.Nil(t, c)
+	assert.Error(t, err)
+
+	c, err = NewHTTPClient("/path/segment/only")
+	assert.Nil(t, c)
+	assert.Error(t, err)
+}
+
 func dump(t *testing.T, v interface{}) {
 	jsonBytes, err := json.MarshalIndent(v, "", "	")
 	if err != nil {