add catch-all effect

docs/tutorial-effects.test.js

@@ -1,7 +1,7 @@
 import { test, expect } from 'vitest';
 
 import u from 'updeep';
-import { action, Updux } from '../src/index.js';
+import { action, Updux, dux } from '../src/index.js';
 
 const addTodoWithId = action('addTodoWithId');
 const incNextId = action('incNextId');
@@ -42,3 +42,28 @@ test( "tutorial example", async () => {
     })
 
 });
+
+test( "catch-all effect", () => {
+
+    let seen = [];
+
+    const foo = new Updux({
+        actions: {
+            one: null,
+            two: null,
+        },
+        effects: {
+            '*': (api) => next => action => {
+                seen.push(action.type);
+                next(action);
+            }
+        }
+    } );
+
+    const store = foo.createStore();
+
+    store.dispatch.one();
+    store.dispatch.two();
+
+    expect(seen).toEqual([ 'one', 'two' ]);
+} )

docs/tutorial.md

@@ -123,3 +123,11 @@ const store = todosDux.createStore();
 store.dispatch.addTodo('Do the thing');
 ```
 
+### Catch-all effect
+
+It is possible to have an effect match all actions via the special `*` token.
+```
+todosUpdux.addEffect('*', () => next => action => {
+    console.log( 'seeing action fly by:', action );
+    next(action);
+});