fix(app): gate one-Tab message focus behind an experiment (#2762)

packages/schema/src/domains/tests/MessageKeyboardFocusSchemas.test.ts

@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {EXPERIMENT_BUCKET_RESOLUTION, experimentBucket} from '@fluxer/schema/src/domains/experiment/ExperimentBucket';
+import {
+	DEFAULT_MESSAGE_KEYBOARD_FOCUS_CONFIG,
+	MessageKeyboardFocusConfigSchema,
+	resolveMessageKeyboardFocusAssignment,
+} from '@fluxer/schema/src/domains/experiment/MessageKeyboardFocusSchemas';
+import {describe, expect, it} from 'vitest';
+
+const USER_ID = '1485064866382176262';
+const OTHER_USER_ID = '1485064866382176263';
+
+function config(overrides: Partial<ReturnType<typeof MessageKeyboardFocusConfigSchema.parse>> = {}) {
+	return MessageKeyboardFocusConfigSchema.parse({...overrides});
+}
+
+describe('message keyboard focus configuration', () => {
+	it('defaults to a disabled rollout that targets nobody', () => {
+		expect(DEFAULT_MESSAGE_KEYBOARD_FOCUS_CONFIG).toEqual({
+			enabled: false,
+			config_version: 0,
+			rollout_basis_points: 0,
+			rollout_salt: 'message-keyboard-focus-v1',
+			included_user_ids: [],
+			excluded_user_ids: [],
+		});
+	});
+
+	it('refuses a rollout wider than the bucket resolution', () => {
+		expect(() => config({rollout_basis_points: EXPERIMENT_BUCKET_RESOLUTION + 1})).toThrow();
+	});
+
+	it('refuses a target that is not a snowflake', () => {
+		expect(() => config({included_user_ids: ['not-a-snowflake']})).toThrow();
+	});
+});
+
+describe('message keyboard focus resolution', () => {
+	it('reports the stored revision while the rollout is disabled', () => {
+		const assignment = resolveMessageKeyboardFocusAssignment(config({config_version: 3}), USER_ID);
+		expect(assignment).toEqual({enabled: false, config_version: 3, user_targeted: false, source: null});
+	});
+
+	it('targets an allowlisted account regardless of its bucket', () => {
+		const assignment = resolveMessageKeyboardFocusAssignment(
+			config({enabled: true, included_user_ids: [USER_ID]}),
+			USER_ID,
+		);
+		expect(assignment).toEqual({enabled: true, config_version: 0, user_targeted: true, source: 'user_rule'});
+	});
+
+	it('keeps a blocklisted account out of a full rollout', () => {
+		const assignment = resolveMessageKeyboardFocusAssignment(
+			config({
+				enabled: true,
+				rollout_basis_points: EXPERIMENT_BUCKET_RESOLUTION,
+				excluded_user_ids: [USER_ID],
+			}),
+			USER_ID,
+		);
+		expect(assignment).toEqual({enabled: true, config_version: 0, user_targeted: false, source: null});
+	});
+
+	it('prefers the blocklist over the allowlist', () => {
+		const assignment = resolveMessageKeyboardFocusAssignment(
+			config({enabled: true, included_user_ids: [USER_ID], excluded_user_ids: [USER_ID]}),
+			USER_ID,
+		);
+		expect(assignment.user_targeted).toBe(false);
+	});
+
+	it('targets an account whose bucket falls inside the rollout', () => {
+		const salt = DEFAULT_MESSAGE_KEYBOARD_FOCUS_CONFIG.rollout_salt;
+		const bucket = experimentBucket(USER_ID, salt);
+		const inside = resolveMessageKeyboardFocusAssignment(
+			config({enabled: true, rollout_basis_points: bucket + 1}),
+			USER_ID,
+		);
+		const outside = resolveMessageKeyboardFocusAssignment(
+			config({enabled: true, rollout_basis_points: bucket}),
+			USER_ID,
+		);
+		expect(inside).toEqual({enabled: true, config_version: 0, user_targeted: true, source: 'canary'});
+		expect(outside).toEqual({enabled: true, config_version: 0, user_targeted: false, source: null});
+	});
+
+	it('separates two accounts under the same salt', () => {
+		const salt = DEFAULT_MESSAGE_KEYBOARD_FOCUS_CONFIG.rollout_salt;
+		expect(experimentBucket(USER_ID, salt)).not.toBe(experimentBucket(OTHER_USER_ID, salt));
+	});
+
+	it('moves an account when the salt changes', () => {
+		expect(experimentBucket(USER_ID, 'message-keyboard-focus-v1')).not.toBe(
+			experimentBucket(USER_ID, 'message-keyboard-focus-v2'),
+		);
+	});
+});