Add function action type to pure (#4130)

* Add function action type to pure * Changeset * Revert unrelated changes --------- Co-authored-by: Mateusz Burzyński <[email protected]>
statelyai · Jul 10, 2023 · e659fac · e659fac
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diff --git a/.changeset/big-coats-fetch.md 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
@@ -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
@@ -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
@@ -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()', () => {