Added test to test for rerendering

README.md

@@ -1,6 +1,8 @@
 # react-use-elmish
 
-`react-use-elmish` - A React hook for unified purely-functional state and effect management.
+A React hook for unified purely-functional state and effect management.
+
+[![Coverage Status](https://coveralls.io/repos/github/ncthbrt/react-use-elmish/badge.svg?branch=master)](https://coveralls.io/github/ncthbrt/react-use-elmish?branch=master) ![GitHub](https://img.shields.io/github/license/ncthbrt/react-use-elmish) ![npm](https://img.shields.io/npm/v/react-use-elmish)
 
 ## What is it?
 

package.json

@@ -14,6 +14,7 @@
     "type": "git",
     "url": "git+https://github.com/ncthbrt/react-use-elmish.git"
   },
+  "homepage": "https://github.com/ncthbrt/react-use-elmish",
   "author": "Nick Cuthbert",
   "license": "MIT",
   "bugs": {

src/useElmish.test.ts

@@ -1,5 +1,6 @@
 import { renderHook, act } from "@testing-library/react-hooks";
 import useElmish, { Effects } from "./index";
+import { render } from "react-dom";
 
 test("should act as a reducer", () => {
   const { result } = renderHook(() =>
@@ -44,3 +45,27 @@ test("should execute effects", async () => {
 
   expect(result.current[0].state).toBe("stoppedSinging");
 });
+
+test("should not trigger rerender if no effects and state the same", async () => {
+  let renderCount = 0;
+  const { result } = renderHook(() => {
+    ++renderCount;
+    return useElmish(
+      (prev, action) => {
+        if (action == "increment") {
+          return [prev + 1, Effects.none()];
+        } else {
+          return [prev, Effects.none()];
+        }
+      },
+      () => [0, Effects.none()]
+    );
+  });
+
+  act(() => {
+    result.current[1]("other");
+  });
+
+  expect(result.current[0]).toBe(0);
+  expect(renderCount).toBe(1);
+});