Add middleware and logic for bootstrapping the session auth

src/auth/SecurityContext.ts

@@ -4,6 +4,7 @@ import {Awaitable, Maybe} from '../util'
 import {Authenticatable, AuthenticatableRepository} from './types'
 import {UserAuthenticatedEvent} from './event/UserAuthenticatedEvent'
 import {UserFlushedEvent} from './event/UserFlushedEvent'
+import {UserAuthenticationResumedEvent} from './event/UserAuthenticationResumedEvent'
 
 /**
  * Base-class for a context that authenticates users and manages security.
@@ -101,6 +102,19 @@ export abstract class SecurityContext {
         }
     }
 
+    /**
+     * Assuming a user is still authenticated in the context,
+     * try to look up and fill in the user.
+     */
+    async resume(): Promise<void> {
+        const credentials = await this.getCredentials()
+        const user = await this.repository.getByCredentials(credentials)
+        if ( user ) {
+            this.authenticatedUser = user
+            await this.bus.dispatch(new UserAuthenticationResumedEvent(user, this))
+        }
+    }
+
     /**
      * Write the current state of the security context to whatever storage
      * medium the context's host provides.
@@ -119,4 +133,11 @@ export abstract class SecurityContext {
     getUser(): Maybe<Authenticatable> {
         return this.authenticatedUser
     }
+
+    /**
+     * Returns true if there is a currently authenticated user.
+     */
+    hasUser(): boolean {
+        return Boolean(this.authenticatedUser)
+    }
 }