From d533ed8cb2863c4f4337a9e177fbfde71e770dac Mon Sep 17 00:00:00 2001
From: Pedro Cattori <pcattori@gmail.com>
Date: Tue, 28 May 2024 12:06:12 -0400
Subject: [PATCH] defineRoute$ types

---
 .../react-router/lib/router/define-route.ts   | 77 +++++++++++++++++++
 packages/react-router/lib/router/utils.ts     | 10 +--
 2 files changed, 81 insertions(+), 6 deletions(-)
 create mode 100644 packages/react-router/lib/router/define-route.ts

diff --git a/packages/react-router/lib/router/define-route.ts b/packages/react-router/lib/router/define-route.ts
new file mode 100644
index 0000000000..d3e99e669c
--- /dev/null
+++ b/packages/react-router/lib/router/define-route.ts
@@ -0,0 +1,77 @@
+import type { ReactNode } from "react";
+
+interface Context {} // TODO: AppLoadContext?
+
+type MaybePromise<T> = T | Promise<T>;
+
+type Serializable =
+  | undefined
+  | null
+  | boolean
+  | string
+  | symbol
+  | number
+  | Array<Serializable>
+  | { [key: PropertyKey]: Serializable }
+  | bigint
+  | Date
+  | URL
+  | RegExp
+  | Error
+  | Map<Serializable, Serializable>
+  | Set<Serializable>
+  | Promise<Serializable>;
+
+export type TypedResponse<T = unknown> = Omit<Response, "json"> & {
+  json(): Promise<T>;
+};
+
+type DataFunctionReturnValue =
+  | Serializable
+  // TODO: | TypedDeferredData<Record<string, unknown>> // do we want to allow `defer()` for back compat?
+  | TypedResponse<Record<string, unknown>>;
+
+// TODO: clientLoader and all the other route module export APIs (meta, handle, ErrorBoundary, etc.)
+
+export type ResponseStub = {
+  status: number | undefined;
+  headers: Headers;
+};
+
+// loader
+type LoaderArgs<Param extends string> = {
+  context: Context;
+  request: Request;
+  params: Record<Param, string>;
+  response: ResponseStub;
+};
+export type Loader<Param extends string> = (
+  args: LoaderArgs<Param>
+) => MaybePromise<DataFunctionReturnValue>;
+
+// action
+type ActionArgs<Param extends string> = {
+  context: Context;
+  request: Request;
+  params: Record<Param, string>;
+  response: ResponseStub;
+};
+export type Action<Param extends string> = (
+  args: ActionArgs<Param>
+) => MaybePromise<DataFunctionReturnValue>;
+
+type Component<P extends string, L extends Loader<P>> = (args: {
+  params: string extends P ? Record<never, string> : Record<P, string>;
+  data: Awaited<ReturnType<L>>;
+}) => ReactNode;
+
+export const defineRoute$ = <
+  const P extends string,
+  L extends Loader<P>,
+  A extends Action<P>
+>(route: {
+  params?: P[];
+  loader?: L;
+  action?: A;
+  component?: Component<NoInfer<P>, NoInfer<L>>;
+}) => route;
diff --git a/packages/react-router/lib/router/utils.ts b/packages/react-router/lib/router/utils.ts
index 561421e777..0af27457d3 100644
--- a/packages/react-router/lib/router/utils.ts
+++ b/packages/react-router/lib/router/utils.ts
@@ -145,11 +145,11 @@ export type Submission =
  * Arguments passed to route loader/action functions.  Same for now but we keep
  * this as a private implementation detail in case they diverge in the future.
  */
-interface DataFunctionArgs<Context> {
+type DataFunctionArgs<Context> = {
   request: Request;
   params: Params;
   context?: Context;
-}
+};
 
 // TODO: (v7) Change the defaults from any to unknown in and remove Remix wrappers:
 //   ActionFunction, ActionFunctionArgs, LoaderFunction, LoaderFunctionArgs
@@ -158,14 +158,12 @@ interface DataFunctionArgs<Context> {
 /**
  * Arguments passed to loader functions
  */
-export interface LoaderFunctionArgs<Context = any>
-  extends DataFunctionArgs<Context> {}
+export type LoaderFunctionArgs<Context = any> = DataFunctionArgs<Context>;
 
 /**
  * Arguments passed to action functions
  */
-export interface ActionFunctionArgs<Context = any>
-  extends DataFunctionArgs<Context> {}
+export type ActionFunctionArgs<Context = any> = DataFunctionArgs<Context>;
 
 /**
  * Loaders and actions can return anything except `undefined` (`null` is a