From dca9691d7d5cde897e109135a7626422b1e04f96 Mon Sep 17 00:00:00 2001
From: Jerko Steiner <jerko.steiner@gmail.com>
Date: Thu, 1 Aug 2019 15:51:59 +0700
Subject: [PATCH] Add ability to easily create redux middleware for async
 actions

---
 packages/jsonrpc/src/redux.test.ts | 33 ++++++++++++++++++++++-----
 packages/jsonrpc/src/redux.ts      | 31 ++++++++++++++++++++++++-
 packages/jsonrpc/src/types.ts      | 36 ++++++++++++++++++------------
 3 files changed, 79 insertions(+), 21 deletions(-)

diff --git a/packages/jsonrpc/src/redux.test.ts b/packages/jsonrpc/src/redux.test.ts
index 7b1698f..4e6d646 100644
--- a/packages/jsonrpc/src/redux.test.ts
+++ b/packages/jsonrpc/src/redux.test.ts
@@ -6,11 +6,11 @@ import bodyParser from 'body-parser'
 import express from 'express'
 import {AddressInfo} from 'net'
 import {Server} from 'http'
-import {createReduxClient} from './redux'
+import {createReduxClient, createReducer} from './redux'
 import {createRemoteClient} from './remote'
 import {jsonrpc} from './express'
 import {keys} from 'ts-transformer-keys'
-import {TActionCreators, TAllActions} from './types'
+import {TPendingActions, TAllActions} from './types'
 
 describe('createReduxClient', () => {
 
@@ -73,9 +73,33 @@ describe('createReduxClient', () => {
     // type R<T> = T extends (...args: any[]) => infer RV ? RV : never
 
     type Client = typeof client
-    type ActionCreators = TActionCreators<typeof client>
+    type ActionCreators = TPendingActions<typeof client>
     type AllActions = TAllActions<typeof client>
 
+    const defaultState = {
+      sum: 1,
+    }
+
+    const create = createReducer('myService', defaultState)
+    <typeof client>((state, action) => {
+      switch (action.method) {
+        case 'add':
+          const r1: number = action.payload
+          return state
+        case 'addAsync':
+          const r2: number = action.payload
+          return state
+        case 'addStringsAsync':
+          const r3: string = action.payload
+          return state
+        case 'addWithContext':
+          const r4: number = action.payload
+          return state
+        default:
+          return state
+      }
+    })
+
     function handleAction(state: any, action: AllActions) {
       if (action.type !== 'myService') {
         return
@@ -99,9 +123,6 @@ describe('createReduxClient', () => {
       }
     }
 
-    // type Values<T> = T[keyof T]
-    // type C = ReturnType<Values<typeof client>>
-
     return client
   }
 
diff --git a/packages/jsonrpc/src/redux.ts b/packages/jsonrpc/src/redux.ts
index 0c3dd47..0c2f660 100644
--- a/packages/jsonrpc/src/redux.ts
+++ b/packages/jsonrpc/src/redux.ts
@@ -1,4 +1,10 @@
-import {TAsyncified, TReduxed} from './types'
+import {
+  IReduxed,
+  TAsyncified,
+  TReduxed,
+  TResolvedActions,
+  TAllActions,
+} from './types'
 import {createRemoteClient} from './remote'
 
 export function createReduxClient<T, ActionType extends string>(
@@ -20,3 +26,26 @@ export function createReduxClient<T, ActionType extends string>(
 
   return service as TReduxed<T, ActionType>
 }
+
+export const createReducer = <ActionType extends string, State>(
+  actionType: ActionType,
+  defaultState: State,
+) => <R extends IReduxed<ActionType>>(
+  handleAction: (state: State, action: TResolvedActions<R>) => State,
+) => (state: State = defaultState, action?: TAllActions<R>): State => {
+  if (!action) {
+    return state
+  }
+  if (action.type !== actionType) {
+    return state
+  }
+  if (action.status === 'pending') {
+    // TODO handle loading
+    return state
+  }
+  if (action.status === 'rejected') {
+    // TODO handle rejected
+    return state
+  }
+  return handleAction(state, action)
+}
diff --git a/packages/jsonrpc/src/types.ts b/packages/jsonrpc/src/types.ts
index 46666b6..60d5f0e 100644
--- a/packages/jsonrpc/src/types.ts
+++ b/packages/jsonrpc/src/types.ts
@@ -2,6 +2,7 @@ type ArgumentTypes<T> =
   T extends (...args: infer U) => infer R ? U : never
 type RetType<T> = T extends (...args: any[]) => infer R ? R : never
 type UnwrapHOC<T> = T extends (...args: any[]) => infer R ? R : T
+type UnwrapPromise<T> = T extends Promise<infer V> ? V : T
 type RetProm<T> = T extends Promise<any> ? T : Promise<T>
 type PromisifyReturnType<T> = (...a: ArgumentTypes<T>) =>
   RetProm<UnwrapHOC<RetType<T>>>
@@ -12,19 +13,13 @@ export type TAsyncified<T> = {
   [K in keyof T]: PromisifyReturnType<T[K]>
 }
 
+export interface IReduxed<ActionType extends string> {
+  [key: string]: (...a: any[]) => IRPCPendingAction<any, ActionType, typeof key>
+}
+
 export type TReduxed<T, ActionType extends string> = {
-  // [K in keyof T]: (...a: ArgumentTypes<T[K]>) => {
-  //   type: ActionType
-  //   payload: RetProm<UnwrapHOC<RetType<T[K]>>>
-  //   method: K
-  //   status: 'pending'
-  // }
-  // [K in keyof T]: (...a: ArgumentTypes<T[K]>) =>
-  //   IPendingAction<RetProm<UnwrapHOC<RetType<T[K]>>>, ActionType> & {
-  //     method: K,
-  //   }
   [K in keyof T]: (...a: ArgumentTypes<T[K]>) =>
-    IRPCPendingAction<UnwrapHOC<RetType<T[K]>>, ActionType, K>
+    IRPCPendingAction<UnwrapPromise<UnwrapHOC<RetType<T[K]>>>, ActionType, K>
 }
 
 export interface IRPCPendingAction<
@@ -45,6 +40,13 @@ export interface IRPCRejectedAction<
   method: Method
 }
 
+export type TRPCAction<
+  T, ActionType extends string, Method extends string | number | symbol
+> =
+  IRPCPendingAction<T, ActionType, Method>
+  | IRPCResolvedAction<T, ActionType, Method>
+  | IRPCRejectedAction<ActionType, Method>
+
 export type TResolved<A> =
   A extends IRPCPendingAction<infer T, infer ActionType, infer Method>
   ? IRPCResolvedAction<T, ActionType, Method>
@@ -55,7 +57,13 @@ export type TRejected<A> =
   ? IRPCRejectedAction<ActionType, Method>
   : never
 
+export type TPending<A> =
+  A extends IRPCPendingAction<infer T, infer ActionType, infer Method>
+  ? IRPCPendingAction<T, ActionType, Method>
+  : never
+
 type Values<T> = T[keyof T]
-export type TActionCreators<T> = RetType<Values<T>>
-export type TAllActions<T> = TActionCreators<T>
-  | TResolved<TActionCreators<T>> | TRejected<TActionCreators<T>>
+export type TPendingActions<T> = TPending<RetType<Values<T>>>
+export type TResolvedActions<T> = TResolved<TPendingActions<T>>
+export type TAllActions<T> = TPendingActions<T>
+  | TResolvedActions<T> | TRejected<TPendingActions<T>>