Set domain on session cookie in session handler

vertx-web/src/main/java/io/vertx/ext/web/handler/SessionHandler.java

@@ -47,6 +47,12 @@ public interface SessionHandler extends PlatformHandler {
 	 */
 	String DEFAULT_SESSION_COOKIE_NAME = "vertx-web.session";
 
+  /**
+   * Default domain of session cookie i.e. no domain is set. More info:
+   * https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie#domaindomain-value
+   */
+  String DEFAULT_SESSION_COOKIE_DOMAIN = null;
+
 	/**
 	 * Default path of session cookie
 	 */
@@ -148,6 +154,19 @@ static SessionHandler create(SessionStore sessionStore) {
 	@Fluent
 	SessionHandler setSessionCookieName(String sessionCookieName);
 
+  /**
+   * Set the session cookie domain. Only the current domain can be set as the
+   * value, or a domain of a higher order, unless it is a public suffix. Setting
+   * the domain will make the cookie available to it, as well as to all its
+   * subdomains. If omitted, this attribute defaults to the host of the current
+   * document URL, not including subdomains.
+   *
+   * @param sessionCookieDomain the session cookie domain
+   * @return a reference to this, so the API can be used fluently
+   */
+  @Fluent
+  SessionHandler setSessionCookieDomain(String sessionCookieDomain);
+
 	/**
 	 * Set the session cookie path
 	 *

vertx-web/src/main/java/io/vertx/ext/web/handler/impl/SessionHandlerImpl.java

@@ -49,6 +49,7 @@ public class SessionHandlerImpl implements SessionHandler {
   private final SessionStore sessionStore;
 
   private String sessionCookieName = DEFAULT_SESSION_COOKIE_NAME;
+  private String sessionCookieDomain = DEFAULT_SESSION_COOKIE_DOMAIN;
   private String sessionCookiePath = DEFAULT_SESSION_COOKIE_PATH;
   private long sessionTimeout = DEFAULT_SESSION_TIMEOUT;
   private boolean nagHttps = DEFAULT_NAG_HTTPS;
@@ -90,6 +91,12 @@ public SessionHandler setCookieHttpOnlyFlag(boolean httpOnly) {
     return this;
   }
 
+  @Override
+  public SessionHandler setSessionCookieDomain(String sessionCookieDomain) {
+    this.sessionCookieDomain = sessionCookieDomain;
+    return this;
+  }
+
   @Override
   public SessionHandler setSessionCookieName(String sessionCookieName) {
     this.sessionCookieName = sessionCookieName;
@@ -150,6 +157,9 @@ public Future<Void> flush(RoutingContext context, boolean ignoreStatus) {
    * @param cookie the cookie to set
    */
   private void setCookieProperties(Cookie cookie, boolean expired) {
+    if (sessionCookieDomain != null) {
+      cookie.setDomain(sessionCookieDomain);
+    }
     cookie.setPath(sessionCookiePath);
     cookie.setSecure(sessionCookieSecure);
     cookie.setHttpOnly(sessionCookieHttpOnly);

vertx-web/src/test/java/io/vertx/ext/web/tests/handler/SessionHandlerTestBase.java

@@ -55,6 +55,26 @@ public void testSessionCookieName() throws Exception {
 		}, 200, "OK", null);
 	}
 
+  @Test
+  public void testSessionCookieDomain() throws Exception {
+    router.route().handler(SessionHandler.create(store).setSessionCookieDomain("example.com"));
+    router.route().handler(rc -> rc.response().end());
+    testRequest(HttpMethod.GET, "/", null, resp -> {
+      String setCookie = resp.headers().get("set-cookie");
+      assertTrue(setCookie.contains("Domain=example.com"));
+    }, 200, "OK", null);
+  }
+
+  @Test
+  public void testSessionCookieDefaultDomain() throws Exception {
+    router.route().handler(SessionHandler.create(store));
+    router.route().handler(rc -> rc.response().end());
+    testRequest(HttpMethod.GET, "/", null, resp -> {
+      String setCookie = resp.headers().get("set-cookie");
+      assertFalse(setCookie.contains("Domain"));
+    }, 200, "OK", null);
+  }
+
 	@Test
 	public void testSessionCookiePath() throws Exception {
 		router.route().handler(SessionHandler.create(store).setSessionCookiePath("/path"));