From 480f085d691c65d7e2c67c13017f3fd4522f257f Mon Sep 17 00:00:00 2001
From: Anton Astashov <aastashov@indeed.com>
Date: Wed, 6 Feb 2019 21:19:59 -0600
Subject: [PATCH] Explicitly specify `Koa.Middleware` params

This way we explicitly state `koa-static` doesn't add anything to Koa's `ctx`
or `ctx.state`.

It's useful because with those changes it won't erase `ctx.state` type,
converting it into `any`. Like, if we have some middleware:

```ts
import Koa from 'koa';

type FooCtx = { foo: string };
const someMiddleware: Koa.Middleware<FooCtx, {}> = (ctx, next) => {
    ctx.state.foo = "foo";
}
```

Before the changes in this PR it would be:

```ts
const app = new Koa<{}, {}>()
    .use(someMiddleware)
    .use(koaStatic("."))
// app is Koa<any, {}>
```

After the changes in this PR:

```ts
const app = new Koa<{}, {}>()
  .use(someMiddleware)
  .use(koaStatic("."))
// app is Koa<FooCtx, {}>
```
---
 types/koa-static/index.d.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/types/koa-static/index.d.ts b/types/koa-static/index.d.ts
index eaba7866c4..34ebc39d53 100644
--- a/types/koa-static/index.d.ts
+++ b/types/koa-static/index.d.ts
@@ -19,7 +19,7 @@ import { Middleware } from "koa";
 
 import { SendOptions } from "koa-send";
 
-declare function serve(root: string, opts?: serve.Options): Middleware;
+declare function serve(root: string, opts?: serve.Options): Middleware<{}>;
 
 declare namespace serve {
     interface Options extends SendOptions {