fix(overmind): fix onInitialize typing

Author: christianalfoni

packages/node_modules/overmind/src/index.ts

@@ -2,7 +2,7 @@ import { ActionChain } from 'action-chain'
 import { EventEmitter } from 'betsy'
 import { ProxyStateTree } from 'proxy-state-tree'
 
-import { createOperators } from './Action'
+import { createOperators, ActionClass, ValueAction } from './Action'
 import { Derived } from './derived'
 import { Devtools, Message, safeValue } from './Devtools'
 import {
@@ -35,6 +35,28 @@ export interface App {}
 
 type IApp = BaseApp & App
 
+export type OnInitialize = (
+  action: ActionClass<
+    {
+      state: IApp['state']
+    } & IApp['effects'],
+    {
+      state: IApp['state']
+      actions: IApp['actions']
+    },
+    any
+  >
+) => ValueAction<
+  {
+    state: IApp['state']
+  } & IApp['effects'],
+  {
+    state: IApp['state']
+    actions: IApp['actions']
+  },
+  any
+>
+
 export type Action<Value = void, ReturnValue = any> = TAction<
   IApp,
   Value,

packages/overmind-website/api/onInitialize.md

@@ -1,11 +1,11 @@
 # OnInitialize
 
-If you need to run logic as the application initializes you can use the **onInitialize** hook. This is defined as a callback and it receives the instance of the application. You can do whatever you want here. Run an action, configure a router etc.
+If you need to run logic as the application initializes you can use the **onInitialize** hook. This is defined as an action and it receives the instance of the application as the input value. You can do whatever you want here. Run an action, configure a router etc.
+
+Typically you would conceptually think of **onInitialize** as "where you bind outside events to actions". So any effect you have configured would typically be configured with what actions to trigger related to events in the effect.
 
 ```marksy
 h(Example, { name: "api/onInitialize" })
 ```
 
-Overmind will run this logic as a promise, meaning that you can return an action you want to run and can later outside of the application detect when the initialization is done. This promise is named **initialized** and can be used as such:
-
 When you use **modules** all the *onInitialize* will run in parallel.

packages/overmind-website/examples/api/onInitialize.ts

@@ -7,8 +7,13 @@ export default (ts, view) =>
           fileName: 'app/onInitialize.ts',
           code: `
 import { OnInitialize } from 'overmind'
+import * as operations from './operations'
+import * as mutations from './mutations'
 
-const onInitialize: OnInitialize = (app) => app.actions.loadData()
+const onInitialize: OnInitialize = action =>
+  action
+    .map(operations.getInitialData)
+    .mutate(mutations.setInitialData)
 
 export default onInitialize
 `,
@@ -35,18 +40,26 @@ const config = {
         {
           fileName: 'app/onInitialize.ts',
           code: `
-export default = (app) => app.actions.loadData()
+import * as operations from './operations'
+import * as mutations from './mutations'
+
+const onInitialize = action =>
+  action
+    .map(operations.getInitialData)
+    .mutate(mutations.setInitialData)
+
+export default onInitialize
 `,
         },
         {
           fileName: 'app/index.js',
           code: `
-import App from 'overmind-${view}'
+import { Overmind } from 'overmind'
 import onInitialize from './onInitialize'
 import * as state from './state'
 import * as actions from './actions'
 
-const app = new App({
+const app = new Overmind({
   onInitialize,
   state,
   actions