feat: add contact form with SMS OTP verification

server/utils/phone-validator.js

@@ -0,0 +1,36 @@
+/**
+ * Normalizes and validates a phone number string based on specific rules.
+ *
+ * The normalization process is as follows:
+ * 1. All non-digit characters are stripped from the input string.
+ * 2. If the resulting number has a leading '1', it is removed.
+ *
+ * After normalization, the function validates that the resulting number
+ * is exactly 10 digits long.
+ *
+ * @param {string} rawPhoneNumber The raw phone number string provided by the user.
+ * @returns {string} The normalized, 10-digit phone number.
+ * @throws {Error} Throws an error if the phone number is invalid after normalization,
+ *                 allowing API endpoints to catch it and return a proper HTTP status.
+ */
+export function normalizeAndValidatePhoneNumber(rawPhoneNumber) {
+  if (!rawPhoneNumber || typeof rawPhoneNumber !== "string") {
+    throw new Error("Phone number is required.");
+  }
+
+  // 1. Strip all non-digit characters.
+  const digitsOnly = rawPhoneNumber.replace(/\D/g, "");
+
+  // 2. If the number starts with a '1', remove it.
+  let numberToValidate = digitsOnly;
+  if (numberToValidate.startsWith("1")) {
+    numberToValidate = numberToValidate.substring(1);
+  }
+
+  // 3. Check if the resulting number is exactly 10 digits long.
+  if (numberToValidate.length !== 10) {
+    throw new Error("Please provide a valid 10-digit phone number.");
+  }
+
+  return numberToValidate;
+}