feat: Add data residency for eu and global regions

docs/use-cases/data-residency-set-hostname.md

@@ -0,0 +1,37 @@
+# Choosing a data-residency to send messages to
+
+Use the `setDataResidency` setter to specify which host to send to:
+
+Send to EU (data-residency: `https://api.eu.sendgrid.com/`)
+```js
+const sgMail = require('@sendgrid/mail');
+sgMail.setDataResidency('eu');
+const msg = {
+  to: 'recipient@example.org',
+  from: 'sender@example.org',
+  subject: 'Hello world',
+  text: 'Hello plain world!',
+  html: '<p>Hello HTML world!</p>',
+};
+sgMail.send(msg);
+```
+Send to Global region, this is also the default host, if the setter is not used
+(data-residency: `https://api.sendgrid.com/`)
+```js
+const sgMail = require('@sendgrid/mail');
+sgMail.setDataResidency('global');
+const msg = {
+  to: 'recipient@example.org',
+  from: 'sender@example.org',
+  subject: 'Hello world',
+  text: 'Hello plain world!',
+  html: '<p>Hello HTML world!</p>',
+};
+sgMail.send(msg);
+```
+
+## Limitations
+
+1. Emails can only be sent to two hosts for now; 'eu' (https://api.eu.sendgrid.com/) and 'global' (https://api.eu.sendgrid.com/)
+2. The default data-residency is https://api.sendgrid.com/
+3. The valid values for `region` in `client.setDataResidency(region)` are only `eu` and `global`. Case-sensitive.

packages/client/src/classes/client.js

@@ -14,11 +14,17 @@ const {
 const API_KEY_PREFIX = 'SG.';
 const SENDGRID_BASE_URL = 'https://api.sendgrid.com/';
 const TWILIO_BASE_URL = 'https://email.twilio.com/';
-
+const SENDGRID_REGION = 'global';
+// Initialize the allowed regions and their corresponding hosts
+const REGION_HOST_MAP = {
+  eu: 'https://api.eu.sendgrid.com/',
+  global: 'https://api.sendgrid.com/',
+};
 class Client {
   constructor() {
     this.auth = '';
     this.impersonateSubuser = '';
+    this.sendgrid_region = SENDGRID_REGION;
 
     this.defaultHeaders = {
       Accept: 'application/json',
@@ -38,7 +44,7 @@ class Client {
 
   setApiKey(apiKey) {
     this.auth = 'Bearer ' + apiKey;
-    this.setDefaultRequest('baseUrl', SENDGRID_BASE_URL);
+    this.setDefaultRequest('baseUrl', REGION_HOST_MAP[this.sendgrid_region]);
 
     if (!this.isValidApiKey(apiKey)) {
       console.warn(`API key does not start with "${API_KEY_PREFIX}".`);
@@ -94,6 +100,21 @@ class Client {
     return this;
   }
 
+  /**
+   * Global is the default residency (or region)
+   * Global region means the message will be sent through https://api.sendgrid.com
+   * EU region means the message will be sent through https://api.eu.sendgrid.com
+   **/
+  setDataResidency(region) {
+    if (!REGION_HOST_MAP.hasOwnProperty(region)) {
+      console.warn('Region can only be "global" or "eu".');
+    } else {
+      this.sendgrid_region = region;
+      this.setDefaultRequest('baseUrl', REGION_HOST_MAP[region]);
+    }
+    return this;
+  }
+
   createHeaders(data) {
     // Merge data with default headers.
     const headers = mergeData(this.defaultHeaders, data);

packages/client/src/client.d.ts

@@ -30,6 +30,11 @@ declare class Client {
    */
   setDefaultRequest<K extends keyof ClientRequest>(key: K | ClientRequest, value ?: ClientRequest[K]): this;
 
+  /**
+   * Sets the data residency as per region provided
+   */
+  setDataResidency(region: string): this;
+
   /**
    * Create headers for request
    */

packages/client/src/client.spec.js

@@ -1,6 +1,7 @@
 'use strict';
 const nock = require('nock');
-
+const sgClient = require('./client');
+let testClient = require('./client');
 const testRequest = (request, statusCode) => {
   const sgClient = require('./client');
   sgClient.setApiKey('SG.API Key');
@@ -3091,3 +3092,55 @@ describe('test_whitelabel_links__link_id__subuser_post', () => {
     return testRequest(request, 200);
   });
 });
+
+describe('setDataResidency', () => {
+  let consoleWarnSpy;
+  beforeEach(() => {
+    testClient = require('./client');
+    consoleWarnSpy = sinon.spy(console, 'warn');
+  });
+  afterEach(() => {
+    console.warn.restore();
+  });
+  it('should have default value of hostname as https://api.sendgrid.com/', () => {
+    expect(testClient.defaultRequest.baseUrl).to.equal('https://api.sendgrid.com/');
+    expect(testClient.sendgrid_region).to.equal('global');
+  });
+  it('should send to host EU', () => {
+    testClient.setDataResidency('eu');
+    expect(testClient.defaultRequest.baseUrl).to.equal('https://api.eu.sendgrid.com/');
+  });
+  it('should send to host Global/default', () => {
+    testClient.setDataResidency('global');
+    expect(testClient.defaultRequest.baseUrl).to.equal('https://api.sendgrid.com/');
+    expect(testClient.sendgrid_region).to.equal('global');
+  });
+  it('should override the existing set hostname, if data residency setter is called after', () => {
+    testClient.setApiKey('SG.1234567890');
+    testClient.setDataResidency('eu');
+    expect(testClient.defaultRequest.baseUrl).to.equal('https://api.eu.sendgrid.com/');
+  });
+  it('should give a warning if the provided value is not allowed', () => {
+    testClient.setDataResidency('');
+    expect(consoleWarnSpy.calledOnce).to.equal(true);
+  });
+  it('should give a warning if the provided value is null', () => {
+    testClient.setDataResidency(null);
+    expect(consoleWarnSpy.calledOnce).to.equal(true);
+  });
+  it('setting the API Key wont reset the region set', () => {
+    testClient.setDataResidency('eu');
+    testClient.setApiKey('SG.1234567890');
+    expect(testClient.defaultRequest.baseUrl).to.equal('https://api.eu.sendgrid.com/');
+    expect(testClient.sendgrid_region).to.equal('eu');
+  });
+  it('should send to host global and then call setApiKey', () => {
+    testClient.setDataResidency('global');
+    testClient.setApiKey('SG.1234567890');
+    expect(testClient.defaultRequest.baseUrl).to.equal('https://api.sendgrid.com/');
+    expect(testClient.sendgrid_region).to.equal('global');
+
+
+  });
+});
+