feat: add epoch event stream to aggregate id

libraries/aggregate.ts

@@ -1,6 +1,6 @@
 import type { AnyEventStore, EventsInsertSettings } from "../libraries/event-store.ts";
 import type { Unknown } from "../types/common.ts";
-import { AggregateSnapshotViolation, AggregateStreamViolation } from "./errors.ts";
+import { AggregateSnapshotViolation } from "./errors.ts";
 import { EventFactory } from "./event-factory.ts";
 
 /**
@@ -27,7 +27,7 @@ export abstract class AggregateRoot<TEventFactory extends EventFactory> {
   /**
    * Primary unique identifier for the stream the aggregate belongs to.
    */
-  #stream?: string;
+  id: string;
 
   /**
    * List of pending records to push to the parent event store.
@@ -40,6 +40,7 @@ export abstract class AggregateRoot<TEventFactory extends EventFactory> {
    * @param store - Store this aggregate instance acts against.
    */
   constructor(store: AnyEventStore) {
+    this.id = crypto.randomUUID();
     this.#store = store;
   }
 
@@ -47,20 +48,6 @@ export abstract class AggregateRoot<TEventFactory extends EventFactory> {
   // Accessors
   // -------------------------------------------------------------------------
 
-  set id(value: string) {
-    if (this.#stream !== undefined) {
-      throw new AggregateStreamViolation(this.constructor.name);
-    }
-    this.#stream = value;
-  }
-
-  get id(): string {
-    if (this.#stream === undefined) {
-      this.#stream = crypto.randomUUID();
-    }
-    return this.#stream;
-  }
-
   get #self(): typeof AggregateRoot<TEventFactory> {
     return this.constructor as typeof AggregateRoot<TEventFactory>;
   }
@@ -147,7 +134,7 @@ export abstract class AggregateRoot<TEventFactory extends EventFactory> {
    * any pending events, make sure to `.save()` before snapshotting.
    */
   async snapshot() {
-    const stream = this.#stream;
+    const stream = this.id;
     if (stream === undefined) {
       throw new AggregateSnapshotViolation(this.#self.name);
     }

libraries/event.ts

@@ -1,7 +1,6 @@
 import z, { ZodType } from "zod";
 
 import { EventValidationError } from "./errors.ts";
-import { makeId } from "./nanoid.ts";
 import { getLogicalTimestamp } from "./time.ts";
 import { toPrettyErrorLines } from "./zod.ts";
 
@@ -41,8 +40,8 @@ export class Event<TEventState extends EventState = EventState> {
     const timestamp = getLogicalTimestamp();
 
     const record = {
-      id: makeId(),
-      stream: payload.stream ?? makeId(),
+      id: crypto.randomUUID(),
+      stream: payload.stream ?? crypto.randomUUID(),
       type: this.state.type,
       data: "data" in payload ? payload.data : null,
       meta: "meta" in payload ? payload.meta : null,
@@ -134,13 +133,13 @@ export type EventRecord<TEvent extends EventState = EventState> = {
   /**
    * A unique event identifier.
    */
-  id: string;
+  id: UUID;
 
   /**
    * Event streams are used to group related events together. This identifier
    * is used to identify the stream to which the event belongs.
    */
-  stream: string;
+  stream: UUID;
 
   /**
    * Type refers to the purpose of the event in a past tense descibing something
@@ -203,3 +202,5 @@ export type EventStatus = {
    */
   outdated: boolean;
 };
+
+export type UUID = `${string}-${string}-${string}-${string}-${string}`;

libraries/nanoid.ts

@@ -1,10 +0,0 @@
-import { nanoid } from "nanoid";
-
-/**
- * Generate a new nanoid.
- *
- * @param size - Size of the id. Default: 11
- */
-export function makeId(size: number = 11): string {
-  return nanoid(size);
-}

libraries/reducer.ts

@@ -19,6 +19,7 @@ export function makeAggregateReducer<
     },
     reduce(events: TEventFactory["$events"][number]["$record"][], snapshot?: Unknown) {
       const instance = aggregate.from(store, snapshot);
+      instance.id = events[0].stream;
       for (const event of events) {
         instance.with(event);
       }