From 581f35cabbc8562558a8f0ef58e7b54eed26a599 Mon Sep 17 00:00:00 2001
From: EskiMojo14 <ben.j.durrant@gmail.com>
Date: Mon, 12 Feb 2024 22:46:54 +0000
Subject: [PATCH] document prefilling initialstate

---
 docs/api/createEntityAdapter.mdx | 33 ++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/docs/api/createEntityAdapter.mdx b/docs/api/createEntityAdapter.mdx
index be14acc886..d08d145bc9 100644
--- a/docs/api/createEntityAdapter.mdx
+++ b/docs/api/createEntityAdapter.mdx
@@ -274,6 +274,39 @@ const booksSlice = createSlice({
 })
 ```
 
+You can also pass in an array of entities or a `Record<EntityId, T>` object to pre-populate the initial state with some entities:
+
+```js
+const booksSlice = createSlice({
+  name: 'books',
+  initialState: booksAdapter.getInitialState(
+    {
+      loading: 'idle',
+    },
+    [
+      { id: 'a', title: 'First' },
+      { id: 'b', title: 'Second' },
+    ],
+  ),
+  reducers: {},
+})
+```
+
+This is equivalent to calling:
+
+```js
+const initialState = booksAdapter.getInitialState({
+  loading: 'idle',
+})
+
+const prePopulatedState = booksAdapter.setAll(initialState, [
+  { id: 'a', title: 'First' },
+  { id: 'b', title: 'Second' },
+])
+```
+
+The first parameter can be `undefined` if no additional properties are needed.
+
 ### Selector Functions
 
 The entity adapter will contain a `getSelectors()` function that returns a set of selectors that know how to read the contents of an entity state object: