1 files changed, 92 insertions, 0 deletions
diff --git a/packages/backend/test/misc/FakeInternalEventService.ts b/packages/backend/test/misc/FakeInternalEventService.ts
new file mode 100644
index 0000000000..d18a080eaf
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+++ b/packages/backend/test/misc/FakeInternalEventService.ts
@@ -0,0 +1,92 @@
+/*
+ * SPDX-FileCopyrightText: hazelnoot and other Sharkey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import type { Listener, ListenerProps } from '@/core/InternalEventService.js';
+import type Redis from 'ioredis';
+import type { GlobalEventService, InternalEventTypes } from '@/core/GlobalEventService.js';
+import { InternalEventService } from '@/core/InternalEventService.js';
+import { bindThis } from '@/decorators.js';
+
+type FakeCall<K extends keyof InternalEventService> = [K, Parameters<InternalEventService[K]>];
+type FakeListener<K extends keyof InternalEventTypes> = [K, Listener<K>, ListenerProps];
+
+/**
+ * Minimal implementation of InternalEventService meant for use in unit tests.
+ * There is no redis connection, and metadata is tracked in the public _calls and _listeners arrays.
+ * The on/off/emit methods are fully functional and can be called in tests to invoke any registered listeners.
+ */
+export class FakeInternalEventService extends InternalEventService {
+	/**
+	 * List of calls to public methods, in chronological order.
+	 */
+	public _calls: FakeCall<keyof InternalEventService>[] = [];
+
+	/**
+	 * List of currently registered listeners.
+	 */
+	public _listeners: FakeListener<keyof InternalEventTypes>[] = [];
+
+	/**
+	 * Resets the mock.
+	 * Clears all listeners and tracked calls.
+	 */
+	public _reset() {
+		this._calls = [];
+		this._listeners = [];
+	}
+
+	/**
+	 * Simulates a remote event sent from another process in the cluster via redis.
+	 */
+	@bindThis
+	public async _emitRedis<K extends keyof InternalEventTypes>(type: K, value: InternalEventTypes[K]): Promise<void> {
+		await this.emit(type, value, false);
+	}
+
+	constructor() {
+		super(
+			{ on: () => {} } as unknown as Redis.Redis,
+			{} as unknown as GlobalEventService,
+		);
+	}
+
+	@bindThis
+	public on<K extends keyof InternalEventTypes>(type: K, listener: Listener<K>, props?: ListenerProps): void {
+		if (!this._listeners.some(l => l[0] === type && l[1] === listener)) {
+			this._listeners.push([type, listener as Listener<keyof InternalEventTypes>, props ?? {}]);
+		}
+		this._calls.push(['on', [type, listener as Listener<keyof InternalEventTypes>, props]]);
+	}
+
+	@bindThis
+	public off<K extends keyof InternalEventTypes>(type: K, listener: Listener<K>): void {
+		this._listeners = this._listeners.filter(l => l[0] !== type || l[1] !== listener);
+		this._calls.push(['off', [type, listener as Listener<keyof InternalEventTypes>]]);
+	}
+
+	@bindThis
+	public async emit<K extends keyof InternalEventTypes>(type: K, value: InternalEventTypes[K], isLocal = true): Promise<void> {
+		for (const listener of this._listeners) {
+			if (listener[0] === type) {
+				if ((isLocal && !listener[2].ignoreLocal) || (!isLocal && !listener[2].ignoreRemote)) {
+					await listener[1](value, type, isLocal);
+				}
+			}
+		}
+		this._calls.push(['emit', [type, value]]);
+	}
+
+	@bindThis
+	public dispose(): void {
+		this._listeners = [];
+		this._calls.push(['dispose', []]);
+	}
+
+	@bindThis
+	public onApplicationShutdown(): void {
+		this._calls.push(['onApplicationShutdown', []]);
+	}
+}
+