feat: add profile auth identity binding flow

backend/internal/handler/auth_oauth_test_helpers_test.go

@@ -0,0 +1,39 @@
+package handler
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func buildEncodedOAuthBindUserCookie(t *testing.T, userID int64, secret string) string {
+	t.Helper()
+	value, err := buildOAuthBindUserCookieValue(userID, secret)
+	require.NoError(t, err)
+	return value
+}
+
+func encodedCookie(name, value string) *http.Cookie {
+	return &http.Cookie{
+		Name:  name,
+		Value: encodeCookieValue(value),
+		Path:  "/",
+	}
+}
+
+func findCookie(cookies []*http.Cookie, name string) *http.Cookie {
+	for _, cookie := range cookies {
+		if cookie.Name == name {
+			return cookie
+		}
+	}
+	return nil
+}
+
+func decodeCookieValueForTest(t *testing.T, value string) string {
+	t.Helper()
+	decoded, err := decodeCookieValue(value)
+	require.NoError(t, err)
+	return decoded
+}