👷 Move preview to lambda

vercel/next.js#8251 (comment)
https://vercel.com/docs/configuration#project/builds

src/pages/api/preview/[sketch].ts → lambdas/preview.ts

@@ -1,10 +1,10 @@
+import path from 'path'
 import SimplexNoise from 'simplex-noise'
 import { createCanvas } from 'canvas'
 
 import { Design, Cut } from 'types'
 import { makeRandomSeed } from 'lib/seeds'
 
-import { settings, design, DesignNoiseSeeds, cut, CutNoiseSeeds } from '../../../../sketches/001'
 
 interface Req {
   query: {
@@ -26,7 +26,7 @@ const handler = async (req: Req, res: Res) => {
   res.setHeader('content-type', 'image/png')
 
   const id = req.query.sketch || '001'
-  // const { settings, design, DesignNoiseSeeds, cut, CutNoiseSeeds } = await import(`../../../../sketches/${id}/index.ts`)
+  const { settings, design, DesignNoiseSeeds, cut, CutNoiseSeeds } = await import(path.resolve(`./sketches/${id}/index.ts`))
 
   const canvasWidth = req.query.width ? parseInt(req.query.width) : 200
   const queryDesignSeeds = req.query.designSeeds ? req.query.designSeeds.split(',') : []

vercel.json

@@ -1,7 +1,21 @@
 {
-  "functions": {
-    "pages/api/preview/[sketch].ts": {
-      "includeFiles": "sketches/**"
+  "builds": [
+    {
+      "src": "next.config.js",
+      "use": "@vercel/next"
+    },
+    {
+      "src": "lambdas/**/*.ts",
+      "use": "@vercel/node",
+      "config": {
+        "includeFiles": ["sketches/**"]
+      }
     }
-  }
+  ],
+  "routes": [
+    {
+      "src": "/lambdas/(.+)",
+      "dest": "/lambdas/$1.ts"
+    }
+  ]
 }