Add support for custom logout function

src/authenticator.ts

@@ -4,7 +4,7 @@ import {
   Session,
   SessionStorage,
 } from "@remix-run/server-runtime";
-import { AuthenticateOptions, Strategy } from "./strategy";
+import { AuthenticateOptions, LogoutOptions, Strategy } from "./strategy";
 
 export interface AuthenticateCallback<User> {
   (user: User): Promise<Response>;
@@ -77,7 +77,7 @@ export class Authenticator<User = unknown> {
    *  .use(new SomeStrategy({}, (user) => Promise.resolve(user)))
    *  .use(new SomeStrategy({}, (user) => Promise.resolve(user)), "another");
    */
-  use(strategy: Strategy<User, never>, name?: string): Authenticator {
+  use(strategy: Strategy<User, never>, name?: string): Authenticator<User> {
     this.strategies.set(name ?? strategy.name, strategy);
     return this;
   }
@@ -88,7 +88,7 @@ export class Authenticator<User = unknown> {
    * @example
    * authenticator.unuse("another").unuse("some");
    */
-  unuse(name: string): Authenticator {
+  unuse(name: string): Authenticator<User> {
     this.strategies.delete(name);
     return this;
   }
@@ -237,12 +237,21 @@ export class Authenticator<User = unknown> {
    */
   async logout(
     request: Request | Session,
-    options: { redirectTo: string }
+    options: LogoutOptions
   ): Promise<never> {
     let session = isSession(request)
       ? request
       : await this.sessionStorage.getSession(request.headers.get("Cookie"));
 
+    let strategyName = session.get(this.sessionStrategyKey);
+    let strategy = this.strategies.get(strategyName);
+
+    let user: User | null = session.get(this.sessionKey) ?? null;
+
+    if (user !== null && typeof strategy?.logout === "function") {
+      return strategy.logout(user, request, this.sessionStorage, options);
+    }
+
     throw redirect(options.redirectTo, {
       headers: {
         "Set-Cookie": await this.sessionStorage.destroySession(session),

src/strategy.ts

@@ -2,6 +2,7 @@ import {
   AppLoadContext,
   json,
   redirect,
+  Session,
   SessionStorage,
 } from "@remix-run/server-runtime";
 import { AuthorizationError } from "./error";
@@ -51,6 +52,10 @@ export interface AuthenticateOptions {
   context?: AppLoadContext;
 }
 
+export interface LogoutOptions {
+  redirectTo: string;
+}
+
 /**
  * A function which will be called to find the user using the information the
  * strategy got from the request.
@@ -168,4 +173,11 @@ export abstract class Strategy<User, VerifyOptions> {
       headers: { "Set-Cookie": await sessionStorage.commitSession(session) },
     });
   }
+
+  public logout?(
+    user: User,
+    request: Request | Session,
+    sessionStorage: SessionStorage,
+    options: LogoutOptions
+  ): Promise<never>;
 }