From 8ad6a341751368b2b4877cf7b8d962137899a59d Mon Sep 17 00:00:00 2001
From: Luis Alvarez <luis@vercel.com>
Date: Mon, 29 Mar 2021 11:25:21 -0600
Subject: [PATCH] Updated types for hooks now using the API

---
 framework/bigcommerce/cart/use-cart.tsx  | 11 +--
 framework/commerce/cart/use-add-item.tsx |  9 +--
 framework/commerce/cart/use-cart.tsx     | 17 +----
 framework/commerce/types/cart.ts         |  5 ++
 framework/commerce/utils/types.ts        | 94 +++++++++++++-----------
 5 files changed, 67 insertions(+), 69 deletions(-)

diff --git a/framework/bigcommerce/cart/use-cart.tsx b/framework/bigcommerce/cart/use-cart.tsx
index 2098e7431..2ef5f606c 100644
--- a/framework/bigcommerce/cart/use-cart.tsx
+++ b/framework/bigcommerce/cart/use-cart.tsx
@@ -1,17 +1,12 @@
 import { useMemo } from 'react'
 import { SWRHook } from '@commerce/utils/types'
-import useCart, { UseCart, FetchCartInput } from '@commerce/cart/use-cart'
+import useCart, { UseCart } from '@commerce/cart/use-cart'
 import { normalizeCart } from '../lib/normalize'
-import type { Cart } from '../types'
+import type { GetCartHook } from '../types/cart'
 
 export default useCart as UseCart<typeof handler>
 
-export const handler: SWRHook<
-  Cart | null,
-  {},
-  FetchCartInput,
-  { isEmpty?: boolean }
-> = {
+export const handler: SWRHook<GetCartHook> = {
   fetchOptions: {
     url: '/api/bigcommerce/cart',
     method: 'GET',
diff --git a/framework/commerce/cart/use-add-item.tsx b/framework/commerce/cart/use-add-item.tsx
index 324464656..072e68674 100644
--- a/framework/commerce/cart/use-add-item.tsx
+++ b/framework/commerce/cart/use-add-item.tsx
@@ -1,17 +1,14 @@
 import { useHook, useMutationHook } from '../utils/use-hook'
 import { mutationFetcher } from '../utils/default-fetcher'
 import type { HookFetcherFn, MutationHook } from '../utils/types'
-import type { Cart, CartItemBody, AddCartItemBody } from '../types'
+import type { AddItemHook } from '../types/cart'
 import type { Provider } from '..'
 
 export type UseAddItem<
-  H extends MutationHook<any, any, any> = MutationHook<Cart, {}, CartItemBody>
+  H extends MutationHook<AddItemHook> = MutationHook<AddItemHook>
 > = ReturnType<H['useHook']>
 
-export const fetcher: HookFetcherFn<
-  Cart,
-  AddCartItemBody<CartItemBody>
-> = mutationFetcher
+export const fetcher: HookFetcherFn<AddItemHook> = mutationFetcher
 
 const fn = (provider: Provider) => provider.cart?.useAddItem!
 
diff --git a/framework/commerce/cart/use-cart.tsx b/framework/commerce/cart/use-cart.tsx
index 98ab9713d..57008a42d 100644
--- a/framework/commerce/cart/use-cart.tsx
+++ b/framework/commerce/cart/use-cart.tsx
@@ -1,23 +1,14 @@
 import Cookies from 'js-cookie'
 import { useHook, useSWRHook } from '../utils/use-hook'
-import type { HookFetcherFn, SWRHook } from '../utils/types'
-import type { Cart } from '../types/cart'
+import type { SWRHook, HookFetcherFn } from '../utils/types'
+import type { GetCartHook } from '../types/cart'
 import { Provider, useCommerce } from '..'
 
-export type FetchCartInput = {
-  cartId?: Cart['id']
-}
-
 export type UseCart<
-  H extends SWRHook<any, any, any> = SWRHook<
-    Cart | null,
-    {},
-    FetchCartInput,
-    { isEmpty?: boolean }
-  >
+  H extends SWRHook<GetCartHook> = SWRHook<GetCartHook>
 > = ReturnType<H['useHook']>
 
-export const fetcher: HookFetcherFn<Cart | null, FetchCartInput> = async ({
+export const fetcher: HookFetcherFn<GetCartHook> = async ({
   options,
   input: { cartId },
   fetch,
diff --git a/framework/commerce/types/cart.ts b/framework/commerce/types/cart.ts
index 82959bf78..91cd3819c 100644
--- a/framework/commerce/types/cart.ts
+++ b/framework/commerce/types/cart.ts
@@ -94,11 +94,16 @@ export type CartHooks = {
 
 export type GetCartHook = {
   data: Cart | null
+  input: {}
+  fetchInput: { cartId?: string }
+  swrState: { isEmpty: boolean }
 }
 
 export type AddItemHook = {
   data: Cart
   body: { item: CartItemBody }
+  input: CartItemBody
+  fetchInput: { item: CartItemBody }
 }
 
 export type UpdateItemHook = {
diff --git a/framework/commerce/utils/types.ts b/framework/commerce/utils/types.ts
index 852afb208..865f7279d 100644
--- a/framework/commerce/utils/types.ts
+++ b/framework/commerce/utils/types.ts
@@ -36,9 +36,13 @@ export type HookFetcher<Data, Input = null, Result = any> = (
   fetch: <T = Result, Body = any>(options: FetcherOptions<Body>) => Promise<T>
 ) => Data | Promise<Data>
 
-export type HookFetcherFn<Data, Input = undefined, Result = any, Body = any> = (
-  context: HookFetcherContext<Input, Result, Body>
-) => Data | Promise<Data>
+export type HookFetcherFn<
+  H extends HookSchemaBase,
+  Result = any,
+  Body = any
+> = (
+  context: HookFetcherContext<H['fetchInput'], Result, Body>
+) => H['data'] | Promise<H['data']>
 
 export type HookFetcherContext<Input = undefined, Result = any, Body = any> = {
   options: HookFetcherOptions
@@ -58,7 +62,7 @@ export type HookSWRInput = [string, HookInputValue][]
 export type HookFetchInput = { [k: string]: HookInputValue }
 
 export type HookFunction<
-  Input extends { [k: string]: unknown } | null,
+  Input extends { [k: string]: unknown } | undefined,
   T
 > = keyof Input extends never
   ? () => T
@@ -66,62 +70,68 @@ export type HookFunction<
   ? (input?: Input) => T
   : (input: Input) => T
 
-export type SWRHook<
+export type HookSchemaBase = {
   // Data obj returned by the hook and fetch operation
-  Data,
+  data: any
   // Input expected by the hook
-  Input extends { [k: string]: unknown } = {},
+  input: {}
   // Input expected before doing a fetch operation
-  FetchInput extends HookFetchInput = {},
+  fetchInput?: {}
+}
+
+export type SWRHookSchemaBase = HookSchemaBase & {
   // Custom state added to the response object of SWR
-  State = {}
-> = {
+  swrState: {}
+}
+
+export type MutationSchemaBase = HookSchemaBase & {
+  // Input expected by the action returned by the hook
+  actionInput?: {}
+}
+
+/**
+ * Generates a SWR hook handler based on the schema of a hook
+ */
+export type SWRHook<H extends SWRHookSchemaBase> = {
   useHook(
-    context: SWRHookContext<Data, FetchInput>
+    context: SWRHookContext<H>
   ): HookFunction<
-    Input & { swrOptions?: SwrOptions<Data, FetchInput> },
-    ResponseState<Data> & State
+    H['input'] & { swrOptions?: SwrOptions<H['data'], H['fetchInput']> },
+    ResponseState<H['data']> & H['swrState']
   >
   fetchOptions: HookFetcherOptions
-  fetcher?: HookFetcherFn<Data, FetchInput>
+  fetcher?: HookFetcherFn<H>
 }
 
-export type SWRHookContext<
-  Data,
-  FetchInput extends { [k: string]: unknown } = {}
-> = {
+type X = {} & undefined
+
+export type SWRHookContext<H extends SWRHookSchemaBase> = {
   useData(context?: {
     input?: HookFetchInput | HookSWRInput
-    swrOptions?: SwrOptions<Data, FetchInput>
-  }): ResponseState<Data>
+    swrOptions?: SwrOptions<H['data'], H['fetchInput']>
+  }): ResponseState<H['data']>
 }
 
-export type MutationHook<
-  // Data obj returned by the hook and fetch operation
-  Data,
-  // Input expected by the hook
-  Input extends { [k: string]: unknown } = {},
-  // Input expected by the action returned by the hook
-  ActionInput extends { [k: string]: unknown } = {},
-  // Input expected before doing a fetch operation
-  FetchInput extends { [k: string]: unknown } = ActionInput
-> = {
+/**
+ * Generates a mutation hook handler based on the schema of a hook
+ */
+export type MutationHook<H extends MutationSchemaBase> = {
   useHook(
-    context: MutationHookContext<Data, FetchInput>
-  ): HookFunction<Input, HookFunction<ActionInput, Data | Promise<Data>>>
+    context: MutationHookContext<H>
+  ): HookFunction<
+    H['input'],
+    HookFunction<H['actionInput'], H['data'] | Promise<H['data']>>
+  >
   fetchOptions: HookFetcherOptions
-  fetcher?: HookFetcherFn<Data, FetchInput>
+  fetcher?: HookFetcherFn<H['data'], H['fetchInput']>
 }
 
-export type MutationHookContext<
-  Data,
-  FetchInput extends { [k: string]: unknown } | null = {}
-> = {
-  fetch: keyof FetchInput extends never
-    ? () => Data | Promise<Data>
-    : Partial<FetchInput> extends FetchInput
-    ? (context?: { input?: FetchInput }) => Data | Promise<Data>
-    : (context: { input: FetchInput }) => Data | Promise<Data>
+export type MutationHookContext<H extends MutationSchemaBase> = {
+  fetch: keyof H['fetchInput'] extends never
+    ? () => H['data'] | Promise<H['data']>
+    : Partial<H['fetchInput']> extends H['fetchInput']
+    ? (context?: { input?: H['fetchInput'] }) => H['data'] | Promise<H['data']>
+    : (context: { input: H['fetchInput'] }) => H['data'] | Promise<H['data']>
 }
 
 export type SwrOptions<Data, Input = null, Result = any> = ConfigInterface<