Extract allowedByWhiteList for unit testability, and add tests

main.go

@@ -128,14 +128,22 @@ func checkAuthorizationHeader(handler http.Handler, r *http.Request, w http.Resp
 	return false
 }
 
-func checkWhitelist(handler http.Handler, r *http.Request, w http.ResponseWriter) bool {
-	if config.Whitelist == "" && config.WhitelistPrefix == "" {
+func allowedByWhiteList(c *Config, p string) bool {
+	if c.Whitelist == "" && c.WhitelistPrefix == "" {
 		return false
 	}
 
-	prefixAllowed := len(config.WhitelistPrefix) > 0 && strings.HasPrefix(r.URL.Path, config.WhitelistPrefix)
+	prefixAllowed := len(c.WhitelistPrefix) > 0 && strings.HasPrefix(p, c.WhitelistPrefix)
 
-	if r.URL.Path == config.Whitelist || prefixAllowed {
+	if p == c.Whitelist || prefixAllowed {
+		return true
+	}
+
+	return false
+}
+
+func checkWhitelist(handler http.Handler, r *http.Request, w http.ResponseWriter) bool {
+	if allowedByWhiteList(config, r.URL.Path) {
 		handler.ServeHTTP(w, r)
 		return true
 	}

main_test.go

@@ -202,3 +202,27 @@ func TestValidPayload(t *testing.T) {
 	assert.Equal(t, username, "user")
 	assert.Equal(t, group, "group")
 }
+
+func TestNotWhitelistedPath(t *testing.T) {
+	c := NewTestConfig()
+	c.Whitelist = ""
+	res := allowedByWhiteList(&c, "/some_path")
+
+	assert.Equal(t, false, res)
+}
+
+func TestWhitelistedPath(t *testing.T) {
+	c := NewTestConfig()
+	c.Whitelist = "/some_path"
+	res := allowedByWhiteList(&c, "/some_path")
+
+	assert.Equal(t, true, res)
+}
+
+func TestWhitelistedPrefixPath(t *testing.T) {
+	c := NewTestConfig()
+	c.WhitelistPrefix = "/prefix/"
+	res := allowedByWhiteList(&c, "/prefix/some_path")
+
+	assert.Equal(t, true, res)
+}