Redirect A/B test variant page to home (#2764)

<!--
PR title: GRW-123 / Feature / Awesome new thing
-->

## Describe your changes

<!--
What changes are made?
If there are many changes, a list might be a good format.
If it makes sense, add screenshots and/or screen recordings here.
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## Justify why they are needed

## Checklist before requesting a review

- [ ] I have performed a self-review of my code

apps/store/experiment.json

@@ -0,0 +1,17 @@
+{
+  "name": "Start page",
+  "slug": "/se",
+  "variants": [
+    {
+      "name": "Original",
+      "id": 0,
+      "weight": 50
+    },
+    {
+      "name": "Variant",
+      "id": 1,
+      "weight": 50,
+      "slug": "/start"
+    }
+  ]
+}

apps/store/next.config.js

@@ -1,6 +1,7 @@
 const withBundleAnalyzer = require('@next/bundle-analyzer')({
   enabled: process.env.ANALYZE === 'true',
 })
+const experimentJson = require('./experiment.json')
 const { SiteCsp, StoryblokCsp } = require('./next-csp.config')
 const { i18n } = require('./next-i18next.config')
 
@@ -93,7 +94,7 @@ module.exports = withBundleAnalyzer({
       ],
     }
   },
-  async redirects() {
+  redirects() {
     const locales = ['no', 'no-en', 'dk', 'dk-en']
     const shutDownMarketsInfo = [
       ...locales.map((locale) => ({
@@ -133,7 +134,7 @@ module.exports = withBundleAnalyzer({
             },
           ]
         : []
-    return [...shutDownMarketsInfo, ...oldSiteCampaigns]
+    return [...shutDownMarketsInfo, ...oldSiteCampaigns, ...getExperimentVariantRedirects()]
   },
 })
 
@@ -156,5 +157,24 @@ const securityHeaders = [
   },
 ]
 
+/**
+ * @returns {import('next').Redirect[]}
+ * */
+const getExperimentVariantRedirects = () => {
+  if (typeof process.env.NEXT_PUBLIC_EXPERIMENT_ID !== 'string') return []
+
+  const variantSlug = experimentJson.variants.find((item) => item.slug).slug
+  if (!variantSlug) return []
+
+  return [
+    {
+      source: [experimentJson.slug, variantSlug].join(''),
+      destination: experimentJson.slug,
+      permanent: false,
+      locale: false,
+    },
+  ]
+}
+
 // Don't delete this console log, useful to see the commerce config in Vercel deployments
 console.log('next.config.js %O', module.exports)

apps/store/src/services/Tracking/experiment.constants.ts

@@ -1,4 +1,5 @@
 export const EXPERIMENT_COOKIE_NAME = 'hedvig-experiment'
+import experimentJson from '../../../experiment.json'
 
 export type Experiment = {
   id: string
@@ -18,21 +19,7 @@ const EXPERIMENT_ID = process.env.NEXT_PUBLIC_EXPERIMENT_ID
 
 export const CURRENT_EXPERIMENT: Experiment | undefined = EXPERIMENT_ID
   ? {
-      name: 'Start page',
+      ...experimentJson,
       id: EXPERIMENT_ID,
-      slug: '/se',
-      variants: [
-        {
-          name: 'Original',
-          id: 0,
-          weight: 50,
-        },
-        {
-          name: 'Variant',
-          id: 1,
-          weight: 50,
-          slug: '/start',
-        },
-      ],
     }
   : undefined