From e659fac5d82e283e1298122814763c59af9a2375 Mon Sep 17 00:00:00 2001
From: David Khourshid <davidkpiano@gmail.com>
Date: Mon, 10 Jul 2023 04:53:18 -0400
Subject: [PATCH] Add function action type to pure (#4130)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

* Add function action type to pure

* Changeset

* Revert unrelated changes

---------

Co-authored-by: Mateusz Burzyński <mateuszburzynski@gmail.com>
---
 .changeset/big-coats-fetch.md      | 12 ++++++++++++
 packages/core/src/actions.ts       |  1 +
 packages/core/src/types.ts         |  4 +++-
 packages/core/test/actions.test.ts | 23 +++++++++++++++++++----
 4 files changed, 35 insertions(+), 5 deletions(-)
 create mode 100644 .changeset/big-coats-fetch.md

diff --git a/.changeset/big-coats-fetch.md b/.changeset/big-coats-fetch.md
new file mode 100644
index 0000000000..b177fca79e
--- /dev/null
+++ b/.changeset/big-coats-fetch.md
@@ -0,0 +1,12 @@
+---
+'xstate': patch
+---
+
+The `pure(...)` action creator is now properly typed so that it allows function actions:
+
+```ts
+actions: pure(() => [
+  // now allowed!
+  (context, event) => { ... }
+])
+```
diff --git a/packages/core/src/actions.ts b/packages/core/src/actions.ts
index 97d298c219..b158047aa9 100644
--- a/packages/core/src/actions.ts
+++ b/packages/core/src/actions.ts
@@ -609,6 +609,7 @@ export function pure<
         | BaseActionObject
         | BaseActionObject['type']
         | ActionObject<TContext, TExpressionEvent, TEvent>
+        | ActionFunction<TContext, TExpressionEvent>
       >
     | undefined
 ): PureAction<TContext, TExpressionEvent, TEvent> {
diff --git a/packages/core/src/types.ts b/packages/core/src/types.ts
index 14cf844585..c592d0d1d8 100644
--- a/packages/core/src/types.ts
+++ b/packages/core/src/types.ts
@@ -1453,7 +1453,9 @@ export interface PureAction<
     event: TEvent
   ) =>
     | SingleOrArray<
-        ActionObject<TContext, TEvent> | ActionObject<TContext, TEvent>['type']
+        | ActionObject<TContext, TEvent>
+        | ActionObject<TContext, TEvent>['type']
+        | ActionFunction<TContext, TEvent>
       >
     | undefined;
 }
diff --git a/packages/core/test/actions.test.ts b/packages/core/test/actions.test.ts
index 7fc9384c61..1b8a62bddf 100644
--- a/packages/core/test/actions.test.ts
+++ b/packages/core/test/actions.test.ts
@@ -1874,7 +1874,7 @@ describe('purely defined actions', () => {
       idle: {
         on: {
           SINGLE: {
-            actions: pure<any, any>((ctx, e) => {
+            actions: pure((ctx, e) => {
               if (ctx.items.length > 0) {
                 return {
                   type: 'SINGLE_EVENT',
@@ -1885,7 +1885,7 @@ describe('purely defined actions', () => {
             })
           },
           NONE: {
-            actions: pure<any, any>((ctx, e) => {
+            actions: pure((ctx, e) => {
               if (ctx.items.length > 5) {
                 return {
                   type: 'SINGLE_EVENT',
@@ -1896,7 +1896,7 @@ describe('purely defined actions', () => {
             })
           },
           EACH: {
-            actions: pure<any, any>((ctx) =>
+            actions: pure((ctx) =>
               ctx.items.map((item: any, index: number) => ({
                 type: 'EVENT',
                 item,
@@ -1905,7 +1905,7 @@ describe('purely defined actions', () => {
             )
           },
           AS_STRINGS: {
-            actions: pure<any, any>(() => ['SOME_ACTION'])
+            actions: pure(() => ['SOME_ACTION'])
           }
         }
       }
@@ -1969,6 +1969,21 @@ describe('purely defined actions', () => {
 
     expect(nextState.actions).toEqual([{ type: 'SOME_ACTION' }]);
   });
+
+  it('should allow function actions in pure', () => {
+    let called = false;
+    const machine = createMachine({
+      entry: pure(() => [
+        () => {
+          called = true;
+        }
+      ])
+    });
+
+    interpret(machine).start();
+
+    expect(called).toBeTruthy();
+  });
 });
 
 describe('forwardTo()', () => {