From a9cb4085214bbf6b1eb7ee5820cb580e875178ae Mon Sep 17 00:00:00 2001
From: Yanick Champoux <yanick@babyl.ca>
Date: Thu, 23 Mar 2023 18:10:33 -0400
Subject: [PATCH] add createPayloadAction

---
 src/Updux.test.ts | 38 ++++++++++++++++++++++++++++++++++++++
 src/actions.ts    | 13 +++++++++++++
 src/index.ts      |  2 +-
 3 files changed, 52 insertions(+), 1 deletion(-)
 create mode 100644 src/Updux.test.ts

diff --git a/src/Updux.test.ts b/src/Updux.test.ts
new file mode 100644
index 0000000..822aaa2
--- /dev/null
+++ b/src/Updux.test.ts
@@ -0,0 +1,38 @@
+import { test, expect } from 'vitest';
+import Updux from './Updux';
+
+test('subdux idempotency', () => {
+    // const c = new Updux({
+    //     initial: 2,
+    // });
+    // const b = new Updux({
+    //     subduxes: {
+    //         c,
+    //     },
+    // });
+    const foo = new Updux({
+        subduxes: {
+            a: new Updux({ initial: 2 }),
+        },
+    });
+
+    let fooState = foo.reducer(undefined, { type: 'noop' });
+    expect(foo.reducer(fooState, { type: 'noop' })).toBe(fooState);
+
+    return;
+    const store = foo.createStore();
+
+    const s1 = store.getState();
+    console.log(s1);
+
+    store.dispatch({ type: 'noop' });
+    const s2 = store.getState();
+
+    expect(s2.a).toBe(s1.a);
+
+    let bState = b.reducer(undefined, { type: 'noop' });
+    expect(b.reducer(bState, { type: 'noop' })).toBe(bState);
+
+    expect(s2.b).toBe(s1.b);
+    expect(s2).toBe(s1);
+});
diff --git a/src/actions.ts b/src/actions.ts
index f8d7dcf..cf559b6 100644
--- a/src/actions.ts
+++ b/src/actions.ts
@@ -13,3 +13,16 @@ export const withPayload: WithPayload = ((prepare) =>
     (...input) => ({
         payload: prepare ? prepare(...input) : input[0],
     })) as any;
+
+export const createPayloadAction = <
+    P extends any = any,
+    T extends string = string,
+    F extends (...args: any[]) => P = (input: P) => P,
+>(
+    type: T,
+    prepare?: F,
+) =>
+    createAction(
+        type,
+        withPayload<ReturnType<F>, Parameters<F>>(prepare ?? (id as any)),
+    );
diff --git a/src/index.ts b/src/index.ts
index 6488bac..6e14d5a 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,5 +1,5 @@
 import Updux from './Updux.js';
 
-export { withPayload, createAction } from './actions.js';
+export { withPayload, createAction, createPayloadAction } from './actions.js';
 
 export default Updux;