Add beforeSendEmail and beforeSendSms blocking functions samples (#1253)

---------

Co-authored-by: Jeff <3759507+jhuleatt@users.noreply.github.com>

Author: macastelaz

Node/quickstarts/auth-blocking-functions/functions/index.js

@@ -17,17 +17,20 @@
 const {
   beforeUserCreated,
   beforeUserSignedIn,
+  beforeEmailSent,
+  beforeSmsSent,
   HttpsError,
 } = require("firebase-functions/identity");
-const {admin} = require("firebase-admin");
+const {defineString} = require("firebase-functions/params");
+const admin = require("firebase-admin");
 
 admin.initializeApp();
 const db = admin.firestore();
 
 // [START v2ValidateNewUser]
 // [START v2beforeCreateFunctionTrigger]
 // Block account creation with any non-acme email address.
-exports.validatenewuser = beforeUserCreated((event) => {
+exports.validateNewUser = beforeUserCreated((event) => {
   // [END v2beforeCreateFunctionTrigger]
   // [START v2readUserData]
   // User data passed in from the CloudEvent.
@@ -47,7 +50,7 @@ exports.validatenewuser = beforeUserCreated((event) => {
 // [START v2CheckForBan]
 // [START v2beforeSignInFunctionTrigger]
 // Block account sign in with any banned account.
-exports.checkforban = beforeUserSignedIn(async (event) => {
+exports.checkForBan = beforeUserSignedIn(async (event) => {
   // [END v2beforeSignInFunctionTrigger]
   // [START v2readEmailData]
   // Email passed from the CloudEvent.
@@ -68,3 +71,61 @@ exports.checkforban = beforeUserSignedIn(async (event) => {
   // [END v2bannedHttpsError]
 });
 // [START v2CheckForBan]
+
+// [START v2CheckEmailDomain]
+// [START v2beforeEmailSentFunctionTrigger]
+// Block email sending with any non-acme email address.
+exports.checkEmailDomain = beforeEmailSent((event) => {
+  // [END v2beforeEmailSentFunctionTrigger]
+  // [START v2readEmailUser]
+  // Email passed in from the CloudEvent.
+  const email = event.data?.email || event.additionalUserInfo?.email;
+  // [END v2readEmailUser]
+
+  // [START v2emailHttpsError]
+  // Only users of a specific domain can receive emails.
+  if (!email) {
+    // Throw an HttpsError so that Firebase Auth rejects the email sending.
+    throw new HttpsError("invalid-argument",
+        "No email was found in the CloudEvent");
+  }
+  if (!email.endsWith("@acme.com")) {
+    throw new HttpsError("permission-denied",
+        "Only users from the acme.com domain can " +
+        "authenticate");
+  }
+  // [END v2emailHttpsError]
+});
+// [END v2CheckEmailDomain]
+
+// [START v2CheckPhoneNumber]
+// [START v2beforeSmsSentFunctionTrigger]
+
+const intlPrefixNumber = defineString("INTERNATIONAL_PREFIX_NUMBER", {
+  default: "+1",
+  description: "The country code that we restrict sending to.",
+});
+// Block SMS sending with any non-US phone number.
+exports.checkPhoneNumber = beforeSmsSent((event) => {
+  // [END v2beforeSmsSentFunctionTrigger]
+  // [START v2readSmsUser]
+  // Phone number passed from the CloudEvent.
+  const phoneNumber = event.data?.phoneNumber ||
+    event.additionalUserInfo?.phoneNumber;
+  // [END v2readSmsUser]
+
+  // [START v2smsHttpsError]
+  if (!phoneNumber) {
+    // Throw an HttpsError so that Firebase Auth rejects the SMS sending.
+    throw new HttpsError("invalid-argument",
+        "No phone number was found in the CloudEvent");
+  }
+
+  // Only users of a specific region can receive SMS.
+  if (!phoneNumber.startsWith(intlPrefixNumber.value())) {
+    // Throw an HttpsError so that Firebase Auth rejects the SMS sending.
+    throw new HttpsError("invalid-argument", "Unauthorized phone number");
+  }
+  // [END v2smsHttpsError]
+});
+// [END v2CheckPhoneNumber]