tidy session storage code

support-frontend/assets/helpers/abTests/abtest.ts

@@ -4,7 +4,6 @@ import type { Settings } from 'helpers/globalsAndSwitches/settings';
 import type { IsoCountry } from 'helpers/internationalisation/country';
 import type { CountryGroupId } from 'helpers/internationalisation/countryGroup';
 import * as cookie from 'helpers/storage/cookie';
-import * as storage from 'helpers/storage/storage';
 import { getQueryParameter } from 'helpers/urls/url';
 import type {
 	AmountsTest,
@@ -23,8 +22,9 @@ import type {
 } from './models';
 import { breakpoints } from './models';
 import {
-	getParticipationsFromSession,
-	setLandingPageParticipations,
+	getSessionParticipations,
+	PARTICIPATIONS_KEY,
+	setSessionParticipations,
 } from './sessionStorage';
 
 export const testIsActive = (
@@ -54,7 +54,7 @@ function init({
 	path = window.location.pathname,
 	settings,
 }: ABtestInitalizerData): Participations {
-	const sessionParticipations = getParticipationsFromSession();
+	const sessionParticipations = getSessionParticipations(PARTICIPATIONS_KEY);
 	const participations = getParticipations(
 		abTests,
 		mvt,
@@ -66,15 +66,13 @@ function init({
 		sessionParticipations,
 	);
 
+	// A landing page test config may be passed through from the server, so we handle this separately
 	const landingPageParticipations = getLandingPageParticipations(
 		countryGroupId,
 		path,
 		settings.landingPageTests,
 		mvt,
 	);
-	if (landingPageParticipations) {
-		setLandingPageParticipations(landingPageParticipations);
-	}
 
 	const urlParticipations = getParticipationsFromUrl();
 	const serverSideParticipations = getServerSideParticipations();
@@ -92,7 +90,7 @@ const MVT_COOKIE = 'GU_mvt_id';
 const MVT_MAX = 1_000_000;
 
 // Attempts to retrieve the MVT id from a cookie, or sets it.
-export function getMvtId(): number {
+function getMvtId(): number {
 	const mvtIdCookieValue = cookie.get(MVT_COOKIE);
 	let mvtId = Number(mvtIdCookieValue);
 
@@ -219,7 +217,7 @@ function getParticipations(
 			sessionParticipations[testId] = participations[testId];
 		}
 	});
-	storage.setSession('abParticipations', JSON.stringify(sessionParticipations));
+	setSessionParticipations(sessionParticipations, PARTICIPATIONS_KEY);
 
 	return participations;
 }

support-frontend/assets/helpers/abTests/landingPageAbTests.ts

@@ -5,7 +5,11 @@ import type {
 } from '../globalsAndSwitches/landingPageSettings';
 import type { CountryGroupId } from '../internationalisation/countryGroup';
 import type { Participations } from './models';
-import { getLandingPageParticipationsFromSession } from './sessionStorage';
+import {
+	getSessionParticipations,
+	LANDING_PAGE_PARTICIPATIONS_KEY,
+	setSessionParticipations,
+} from './sessionStorage';
 
 export type LandingPageSelection = LandingPageVariant & { testName: string };
 
@@ -49,14 +53,21 @@ export function getLandingPageParticipations(
 			const variant = test.variants[idx];
 
 			if (variant) {
-				return {
+				const participations = {
 					[test.name]: variant.name,
 				};
+				// Record the participation in session storage so that we can track it from the checkout
+				setSessionParticipations(
+					participations,
+					LANDING_PAGE_PARTICIPATIONS_KEY,
+				);
+
+				return participations;
 			}
 		}
 	} else {
 		// This is not a landing page, but check if the session has a landing page test participation
-		return getLandingPageParticipationsFromSession();
+		return getSessionParticipations(LANDING_PAGE_PARTICIPATIONS_KEY);
 	}
 }
 

support-frontend/assets/helpers/abTests/sessionStorage.ts

@@ -1,38 +1,30 @@
 import * as storage from '../storage/storage';
 import type { Participations } from './models';
 
-function getParticipationsFromSession(
-	key: string = 'abParticipations',
-): Participations | undefined {
+const PARTICIPATIONS_KEY = 'abParticipations';
+const LANDING_PAGE_PARTICIPATIONS_KEY = 'landingPageParticipations';
+type Key = typeof PARTICIPATIONS_KEY | typeof LANDING_PAGE_PARTICIPATIONS_KEY;
+
+function getSessionParticipations(key: Key): Participations | undefined {
 	const participations = storage.getSession(key);
 	if (participations) {
 		try {
 			return JSON.parse(participations) as Participations;
 		} catch (error) {
-			console.error(
-				'Failed to parse abParticipations from session storage',
-				error,
-			);
+			console.error(`Failed to parse ${key} from session storage`, error);
 			return undefined;
 		}
 	}
 	return undefined;
 }
 
-const landingPageParticipationsKey = 'landingPageParticipations';
-function getLandingPageParticipationsFromSession(): Participations | undefined {
-	return getParticipationsFromSession(landingPageParticipationsKey);
-}
-
-function setLandingPageParticipations(participations: Participations) {
-	storage.setSession(
-		landingPageParticipationsKey,
-		JSON.stringify(participations),
-	);
+function setSessionParticipations(participations: Participations, key: Key) {
+	storage.setSession(key, JSON.stringify(participations));
 }
 
 export {
-	getParticipationsFromSession,
-	getLandingPageParticipationsFromSession,
-	setLandingPageParticipations,
+	getSessionParticipations,
+	setSessionParticipations,
+	PARTICIPATIONS_KEY,
+	LANDING_PAGE_PARTICIPATIONS_KEY,
 };