GitBook: [v27] 2 pages modified

Author: christianalfoni

api-1/createovermindmock.md

@@ -48,3 +48,26 @@ describe('Actions', () => {
 It is important that you separate your **config** from the instantiation of Overmind, meaning that **createOvermind** should not be used in the same file as the config you see imported here, it should rather be used where you render your application. This allows the config to be used for multiple purposes.
 {% endhint %}
 
+## Setting initial state
+
+Pass a function as the second or third argument to set initial state.
+
+{% tabs %}
+{% tab title="overmind/actions.test.js" %}
+```typescript
+import { createOvermindMock } from 'overmind'
+import { config } from './'
+
+describe('State', () => {
+  test('should derive authors of posts', async () => {
+    const overmind = createOvermindMock(config, (state) => {
+      state.posts = { 1: { id: 1, author: 'Janet' } }
+    })
+
+    expect(overmind.state.authors).toEqual(['Janet'])
+  })
+})
+```
+{% endtab %}
+{% endtabs %}
+

guides-1/testing.md

@@ -13,7 +13,6 @@ When you write tests you will create many instances of a mocked version of Overm
 {% tabs %}
 {% tab title="overmind/index.js" %}
 ```typescript
-import { IConfig } from 'overmind'
 import { state } from './state'
 
 export const config = {
@@ -34,6 +33,29 @@ const overmind = createOvermind(config)
 
 Now we are free to import our configuration without touching the application instance. Lets go!
 
+## Setting initial state
+
+By passing a function either as second or third argument you can change the initial state of Overmind.
+
+{% tabs %}
+{% tab title="overmind/actions.test.js" %}
+```typescript
+import { createOvermindMock } from 'overmind'
+import { config } from './'
+
+describe('State', () => {
+  test('should derive authors of posts', async () => {
+    const overmind = createOvermindMock(config, (state) => {
+      state.posts = { 1: { id: 1, author: 'Janet' } }
+    })
+
+    expect(overmind.state.authors).toEqual(['Janet'])
+  })
+})
+```
+{% endtab %}
+{% endtabs %}
+
 ## Testing actions
 
 When testing an action you’ll want to verify that changes to state are performed as expected. To give you the best possible testing experience Overmind comes with a mocking tool called **createOvermindMock**. It takes your application configuration and allows you to run actions as if they were run from components.