feat: version 2 beta

adapters/mongo/adapter.ts

@@ -0,0 +1,91 @@
+import type { MongoConnectionUrl } from "@valkyr/testcontainers/mongodb";
+import { Db, MongoClient } from "mongodb";
+
+import { EventStoreAdapter } from "../../types/adapter.ts";
+import { registrars } from "./collections/mod.ts";
+import { MongoEventsProvider } from "./providers/events.ts";
+import { MongoRelationsProvider } from "./providers/relations.ts";
+import { MongoSnapshotsProvider } from "./providers/snapshots.ts";
+import { DatabaseAccessor } from "./types.ts";
+import { getCollectionsSet } from "./utilities.ts";
+
+/**
+ * A server-based event store adapter that integrates database-specific providers.
+ *
+ * The `MongoAdapter` enables event sourcing in a back end environment by utilizing
+ * MongoDB for storage. It provides implementations for event storage, relations,
+ * and snapshots, allowing seamless integration with the shared event store interface.
+ *
+ * @template TEvent - The type of events managed by the event store.
+ */
+export class MongoAdapter implements EventStoreAdapter<DatabaseAccessor> {
+  readonly providers: {
+    readonly events: MongoEventsProvider;
+    readonly relations: MongoRelationsProvider;
+    readonly snapshots: MongoSnapshotsProvider;
+  };
+
+  readonly #accessor: DatabaseAccessor;
+
+  constructor(connection: MongoConnection, db: string) {
+    this.#accessor = getDatabaseAccessor(connection, db);
+    this.providers = {
+      events: new MongoEventsProvider(this.#accessor),
+      relations: new MongoRelationsProvider(this.#accessor),
+      snapshots: new MongoSnapshotsProvider(this.#accessor),
+    };
+  }
+
+  get db(): DatabaseAccessor {
+    return this.#accessor;
+  }
+}
+
+/**
+ * Takes a mongo database and registers the event store collections and
+ * indexes defined internally.
+ *
+ * @param db     - Mongo database to register event store collections against.
+ * @param logger - Logger method to print internal logs.
+ */
+export async function register(db: Db, logger?: (...args: any[]) => any) {
+  const list = await getCollectionsSet(db);
+  for (const { name, indexes } of registrars) {
+    if (list.has(name)) {
+      continue;
+    }
+    await db.createCollection(name);
+    for (const [indexSpec, options] of indexes) {
+      await db.collection(name).createIndex(indexSpec, options);
+      logger?.("Mongo Event Store > Collection '%s' is indexed [%O] with options %O", name, indexSpec, options ?? {});
+    }
+    logger?.("Mongo Event Store > Collection '%s' is registered", name);
+  }
+}
+
+function getDatabaseAccessor(connection: MongoConnection, database: string): DatabaseAccessor {
+  let instance: Db | undefined;
+  return {
+    get db(): Db {
+      if (instance === undefined) {
+        instance = this.client.db(database);
+      }
+      return instance;
+    },
+    get client(): MongoClient {
+      if (typeof connection === "string") {
+        return new MongoClient(connection);
+      }
+      if (connection instanceof MongoClient) {
+        return connection;
+      }
+      return connection();
+    },
+  };
+}
+
+/**
+ * Connection which the adapter supports, this can be a `url`, a `client` instance
+ * or a lazy method that provided `client` instance on demand.
+ */
+export type MongoConnection = MongoConnectionUrl | MongoClient | (() => MongoClient);