typed wrangler injection

main.ts

import {
  unstable_readConfig,
  unstable_convertConfigBindingsToStartWorkerBindings,
} from "wrangler";
import * as fs from "node:fs";
import * as z from "zod";
import tmp from 'tmp';


const WranglerOverrides = z.object({
  aiGatewayId: z.string(),
  hyperdrive: z.discriminatedUnion("type", [
    z.object({
      type: z.literal("local"),
      local: z.object({
        localConnectionString: z.string(),
      }),
    }),
    z.object({
      type: z.literal("hyperdrive"),
      hyperdrive: z.object({
        id: z.string(),
      }),
    }),
  ]),
});


const { input } = JSON.parse(fs.readFileSync(0, "utf-8"));
const wranglerOverrides = WranglerOverrides.parse(input);
const wranglerConfigRaw = {
  $schema: "node_modules/wrangler/config-schema.json",
  name: "fllwp",
  main: "src/index.tsx",
  compatibility_date: "2025-05-31",
  compatibility_flags: ["nodejs_compat"],
  ai: {
    binding: "AI",
  },
  hyperdrive: [
    {
      binding: "HYPERDRIVE",
      ...wranglerOverrides.hyperdrive[wranglerOverrides.hyperdrive.type]
    },
  ],
  vars: {
    AI_GATEWAY_ID: wranglerOverrides.aiGatewayId,
  },
  assets: {
    binding: "ASSETS",
  },
};

tmp.file(null, (err, path, fd, cleanupCallback) => {
  if (err) throw err;
  const config = unstable_readConfig({config: path});

  fs.writeFileSync(fd, JSON.stringify(wranglerConfigRaw))
  fs.close(fd)

  console.log(
    JSON.stringify({
      config: JSON.stringify(config),
    }),
  );

  cleanupCallback();
});