chore: Email + mailer refactor (#3342)

* Huge email refactor

* fix: One rename too many

* comments

server/queues/tasks/BaseTask.ts

@@ -9,6 +9,12 @@ export enum TaskPriority {
 }
 
 export default abstract class BaseTask<T> {
+  /**
+   * Schedule this task type to be processed asyncronously by a worker.
+   *
+   * @param props Properties to be used by the task
+   * @returns A promise that resolves once the job is placed on the task queue
+   */
   public static schedule<T>(props: T) {
     // @ts-expect-error cannot create an instance of an abstract class, we wont
     const task = new this();
@@ -21,8 +27,17 @@ export default abstract class BaseTask<T> {
     );
   }
 
+  /**
+   * Execute the task.
+   *
+   * @param props Properties to be used by the task
+   * @returns A promise that resolves once the task has completed.
+   */
   public abstract perform(props: T): Promise<void>;
 
+  /**
+   * Job options such as priority and retry strategy, as defined by Bull.
+   */
   public get options(): JobOptions {
     return {
       priority: TaskPriority.Normal,

server/queues/tasks/EmailTask.ts

@@ -1,15 +1,23 @@
+import emails from "@server/emails/templates";
 import { APM } from "@server/logging/tracing";
-import mailer, { EmailSendOptions, EmailTypes } from "../../mailer";
 import BaseTask from "./BaseTask";
 
 type Props = {
-  type: EmailTypes;
-  options: EmailSendOptions;
+  templateName: string;
+  props: Record<string, any>;
 };
 
 @APM.trace()
 export default class EmailTask extends BaseTask<Props> {
-  public async perform(props: Props) {
-    await mailer[props.type](props.options);
+  public async perform({ templateName, props }: Props) {
+    const EmailClass = emails[templateName];
+    if (!EmailClass) {
+      throw new Error(
+        `Email task "${templateName}" template does not exist. Check the file name matches the class name.`
+      );
+    }
+
+    const email = new EmailClass(props);
+    return email.send();
   }
 }