feat(core): factory-form Platform/Resource for parametric default exports

[sam-goodwin]

Adds a factory overload for Platform/Resource so a default-exported worker can be parametric, and uses it to fix Cloudflare.state({ workerName }) end-to-end.

// User-facing: parametric default export
export default Worker((scriptName: string) => [
  "Api",
  {
    name: scriptName,
    main: import.meta.filename,
    ...
  },
  Effect.gen(function* () { ... }),
]);

The factory function returns the same [id, props, body] tuple the positional Worker(id, props, body) form accepts — no nested Worker(...Worker(...)). Resource (non-Platform) takes a [id, props] 2-tuple.

At deploy time, yield* MyWorker(...args) applies the tuple to the constructor and stamps each arg into Props.env as its own binding (__ALCHEMY_FACTORY_ARG_<i>__, plus __ALCHEMY_FACTORY_ARG_COUNT__). Top-level Redacted args ride the secret_text lifecycle; everything else rides plain_text. Output args resolve at deploy time via the engine's normal Output resolver, so Output<Redacted<string>> lands on secret_text too — same encoding as the existing ctx.set/ctx.get pair.

+import * as Redacted from "effect/Redacted";

+const __decodeFactoryArg = (raw) => {
+  if (raw == null) return raw;
+  try {
+    const parsed = JSON.parse(raw);
+    if (parsed?._tag === "Redacted" && "value" in parsed) {
+      return Redacted.make(parsed.value);
+    }
+    return parsed;
+  } catch { return raw; }
+};
+const __alchemyFactoryArgs = Array.from(
+  { length: parseInt(env.__ALCHEMY_FACTORY_ARG_COUNT__ ?? "0", 10) },
+  (_, i) => __decodeFactoryArg(env["__ALCHEMY_FACTORY_ARG_" + i + "__"]),
+);
+const resolved = entry?.__alchemyFactory ? entry(...__alchemyFactoryArgs) : entry;

 const tag = Context.Service("...")
 const layer =
-  typeof entry?.build === "function"
-    ? entry
-    : Layer.effect(tag, typeof entry?.asEffect === "function" ? entry.asEffect() : entry);
+  typeof resolved?.build === "function"
+    ? resolved
+    : Layer.effect(tag, typeof resolved?.asEffect === "function" ? resolved.asEffect() : resolved);

Cloudflare/StateStore/Api.ts switches to the factory form. Combined with the existing loginWithCloudflare(scriptName) change, Cloudflare.state({ workerName: "custom-state" }) now deploys and looks up custom-state — the bug that motivated this work.

🤖 Generated with Claude Code

[alchemy-version-bot]

Install the packages built from this commit:

alchemy

bun add alchemy@https://pkg.ing/alchemy/af49738

@alchemy.run/better-auth

bun add @alchemy.run/better-auth@https://pkg.ing/@alchemy.run/better-auth/af49738

@alchemy.run/pr-package

bun add @alchemy.run/pr-package@https://pkg.ing/@alchemy.run/pr-package/af49738