fix(admin): allow single community mode to be turned back on (#1684)

fluxer_api/src/api/instance/tests/SingleCommunityService.test.ts

@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {describe, expect, it} from 'vitest';
+import type {User} from '../../models/User';
+import type {InstancePolicyConfig} from '../InstanceConfigRepository';
+import {SingleCommunityService} from '../SingleCommunityService';
+
+const EXISTING_GUILD_ID = '1234567890123456789';
+const OWNER = {id: 42n} as unknown as User;
+
+interface Harness {
+	service: SingleCommunityService;
+	written: Array<Partial<InstancePolicyConfig>>;
+	createdNames: Array<string>;
+}
+
+function createHarness(params: {designatedGuildId: string | null; designatedGuildExists: boolean}): Harness {
+	const written: Array<Partial<InstancePolicyConfig>> = [];
+	const createdNames: Array<string> = [];
+	let nextCreatedGuildId = 999n;
+	const instanceConfigRepository = {
+		getInstancePolicyConfig: async () => ({
+			single_community_enabled: false,
+			single_community_guild_id: params.designatedGuildId,
+		}),
+		setInstancePolicyConfig: async (patch: Partial<InstancePolicyConfig>) => {
+			written.push(patch);
+		},
+	};
+	const guildDataService = {
+		getGuildSystem: async () => {
+			if (!params.designatedGuildExists) {
+				throw new Error('unknown guild');
+			}
+			return {} as never;
+		},
+		createGuild: async ({data}: {data: {name: string}}) => {
+			createdNames.push(data.name);
+			nextCreatedGuildId += 1n;
+			return {id: nextCreatedGuildId.toString()} as never;
+		},
+	};
+	const service = new SingleCommunityService(
+		instanceConfigRepository as never,
+		guildDataService as never,
+		null as never,
+	);
+	return {service, written, createdNames};
+}
+
+describe('SingleCommunityService.ensureStockCommunity', () => {
+	it('reuses the designated community when it still exists', async () => {
+		const harness = createHarness({designatedGuildId: EXISTING_GUILD_ID, designatedGuildExists: true});
+		const guildId = await harness.service.ensureStockCommunity({owner: OWNER, name: 'Fluxer'});
+		expect(guildId.toString()).toBe(EXISTING_GUILD_ID);
+		expect(harness.createdNames).toEqual([]);
+		expect(harness.written).toEqual([{single_community_enabled: true, single_community_guild_id: EXISTING_GUILD_ID}]);
+	});
+
+	it('creates a fresh community when the designated one was deleted', async () => {
+		const harness = createHarness({designatedGuildId: EXISTING_GUILD_ID, designatedGuildExists: false});
+		const guildId = await harness.service.ensureStockCommunity({owner: OWNER, name: 'Fluxer'});
+		expect(guildId.toString()).not.toBe(EXISTING_GUILD_ID);
+		expect(harness.createdNames).toEqual(['Fluxer']);
+	});
+
+	it('creates a fresh community when the instance never designated one', async () => {
+		const harness = createHarness({designatedGuildId: null, designatedGuildExists: false});
+		await harness.service.ensureStockCommunity({owner: OWNER, name: 'Fluxer'});
+		expect(harness.createdNames).toEqual(['Fluxer']);
+	});
+
+	it('creates a fresh community when the stored guild id is not a snowflake', async () => {
+		const harness = createHarness({designatedGuildId: 'not-a-snowflake', designatedGuildExists: true});
+		await harness.service.ensureStockCommunity({owner: OWNER, name: 'Fluxer'});
+		expect(harness.createdNames).toEqual(['Fluxer']);
+	});
+});