61 lines
1.6 KiB
TypeScript
61 lines
1.6 KiB
TypeScript
import { appendFile } from "node:fs/promises";
|
|
import EventStore from "../domain/EventStore";
|
|
import { ApplicationUpdateStarted } from "../domain/events/ApplicationUpdateStarted";
|
|
|
|
export default class FileEventStore implements EventStore {
|
|
private handlers: DomainProjection[] = [];
|
|
constructor(private readonly filePath: string) {}
|
|
|
|
append(event: DomainEvent<any>): void {
|
|
appendFile(this.filePath, this.serialize(event) + "\n");
|
|
this.emit(event);
|
|
}
|
|
|
|
subscribe(projection: DomainProjection) {
|
|
this.handlers.push(projection);
|
|
}
|
|
|
|
async replay() {
|
|
// TODO Improve this with streaming
|
|
console.log("Replaying events from", this.filePath);
|
|
const file = Bun.file(this.filePath);
|
|
const content = await file.text();
|
|
const lines = content.split("\n");
|
|
for (const line of lines) {
|
|
if (!line) {
|
|
continue;
|
|
}
|
|
console.log("Deserializing", line);
|
|
const event = this.deserialize(line);
|
|
this.emit(event);
|
|
}
|
|
console.log("Replaying done");
|
|
}
|
|
|
|
private emit(event: DomainEvent<any>) {
|
|
for (const handler of this.handlers) {
|
|
handler.handle(event);
|
|
}
|
|
}
|
|
|
|
private serialize(event: DomainEvent<any>) {
|
|
return JSON.stringify(event);
|
|
}
|
|
|
|
private deserialize(line: string) {
|
|
const event = JSON.parse(line);
|
|
switch (event.type) {
|
|
case "ApplicationUpdateStarted":
|
|
return new ApplicationUpdateStarted(
|
|
{
|
|
id: event.payload.id,
|
|
newVersion: event.payload.newVersion,
|
|
},
|
|
new Date(event.createdAt)
|
|
);
|
|
default:
|
|
throw new Error("Unknown event type" + event.type);
|
|
}
|
|
}
|
|
}
|