Fix developers RSC route rewrites (#602)

Author: decofe

src/lib/vercel-routing.test.ts

@@ -0,0 +1,32 @@
+import fs from 'node:fs'
+import { describe, expect, it } from 'vitest'
+
+type VercelConfig = {
+  rewrites?: Array<{ source: string; destination: string }>
+}
+
+describe('Vercel routing', () => {
+  it('normalizes doubled /developers RSC routes at the edge', () => {
+    const config = JSON.parse(fs.readFileSync('vercel.json', 'utf8')) as VercelConfig
+    const rewrites = config.rewrites ?? []
+
+    expect(rewrites.slice(0, 4)).toEqual([
+      {
+        source: '/developers/RSC/R/developers.txt',
+        destination: '/developers/RSC/R/_root.txt',
+      },
+      {
+        source: '/developers/RSC/R/developers/:path(.*)',
+        destination: '/developers/RSC/R/:path',
+      },
+      {
+        source: '/RSC/R/developers.txt',
+        destination: '/RSC/R/_root.txt',
+      },
+      {
+        source: '/RSC/R/developers/:path(.*)',
+        destination: '/RSC/R/:path',
+      },
+    ])
+  })
+})

vercel.json

@@ -286,6 +286,22 @@
     }
   ],
   "rewrites": [
+    {
+      "source": "/developers/RSC/R/developers.txt",
+      "destination": "/developers/RSC/R/_root.txt"
+    },
+    {
+      "source": "/developers/RSC/R/developers/:path(.*)",
+      "destination": "/developers/RSC/R/:path"
+    },
+    {
+      "source": "/RSC/R/developers.txt",
+      "destination": "/RSC/R/_root.txt"
+    },
+    {
+      "source": "/RSC/R/developers/:path(.*)",
+      "destination": "/RSC/R/:path"
+    },
     {
       "source": "/ingest/static/:path(.*)",
       "destination": "https://us-assets.i.posthog.com/static/:path"