fix some type errors

components/App.tsx

@@ -13,7 +13,7 @@ class App extends Component {
   }
 
   render() {
-    const state = this.state || {}
+    const state: Record<string, unknown> = this.state || {}
 
     return (
       <div className="home">

components/List.tsx

@@ -1,19 +0,0 @@
-import * as React from 'react'
-import ListItem from './ListItem'
-import { User } from '../interfaces'
-
-type Props = {
-  items: User[]
-}
-
-const List = ({ items }: Props) => (
-  <ul>
-    {items.map((item) => (
-      <li key={item.id}>
-        <ListItem data={item} />
-      </li>
-    ))}
-  </ul>
-)
-
-export default List

components/ListDetail.tsx

@@ -1,16 +0,0 @@
-import * as React from 'react'
-
-import { User } from '../interfaces'
-
-type ListDetailProps = {
-  item: User
-}
-
-const ListDetail = ({ item: user }: ListDetailProps) => (
-  <div>
-    <h1>Detail for {user.name}</h1>
-    <p>ID: {user.id}</p>
-  </div>
-)
-
-export default ListDetail

components/ListItem.tsx

@@ -1,18 +0,0 @@
-import React from 'react'
-import Link from 'next/link'
-
-import { User } from '../interfaces'
-
-type Props = {
-  data: User
-}
-
-const ListItem = ({ data }: Props) => (
-  <Link href="/users/[id]" as={`/users/${data.id}`}>
-    <a>
-      {data.id}: {data.name}
-    </a>
-  </Link>
-)
-
-export default ListItem

components/apiHelper.tsx

@@ -1,12 +1,10 @@
-function checkStatus(res) {
+function checkStatus(res: Response) {
   if (res.status < 200 || res.status >= 400) {
     throw new Error(`Something went wrong (Status ${res.status}) - I do feel very sorry!`)
   }
-
-  return res
 }
 
-export function generatePdf(state) {
+export async function generatePdf(state: Record<string, string>) {
   const options = {
     method: 'POST',
     headers: {
@@ -15,17 +13,19 @@ export function generatePdf(state) {
     body: JSON.stringify(state),
   }
 
-  return fetch('/api/pdf/generate/brief', options)
-    .then(checkStatus)
-    .then((res) => res.json())
+  const response = await fetch('/api/pdf/generate/brief', options)
+  checkStatus(response)
+  return response.json()
 }
 
-export function getLatest() {
-  return fetch('/api/pdf/latest')
-    .then(checkStatus)
-    .then((res) => res.json())
+export async function getLatest() {
+  const response = await fetch('/api/pdf/latest')
+  checkStatus(response)
+  return response.json()
 }
 
-export function removeLatest(item) {
-  return fetch(`/api/pdf/latest/${item.id}`, { method: 'DELETE' }).then(checkStatus)
+export async function removeLatest(item: { id: string }) {
+  const response = await fetch(`/api/pdf/latest/${item.id}`, { method: 'DELETE' })
+  checkStatus(response)
+  return response
 }