test: tests for memoize

packages/runtime-core/__tests__/memoize.spec.ts

@@ -0,0 +1,54 @@
+import { h, Component, memoize, nextTick } from '../src'
+import { renderIntsance, serialize } from '@vue/runtime-test'
+
+describe('memoize', () => {
+  it('should work', async () => {
+    class App extends Component {
+      count = 1
+      render() {
+        return h('div', [
+          this.count,
+          this.count % 2
+            ? memoize(() => h('div', `A` + this.count), this, 0)
+            : null,
+          memoize(() => h('div', `B` + this.count), this, 1)
+        ])
+      }
+    }
+
+    const app = renderIntsance(App)
+    expect(serialize(app.$el)).toBe(`<div>1<div>A1</div><div>B1</div></div>`)
+
+    app.count++
+    await nextTick()
+    expect(serialize(app.$el)).toBe(`<div>2<div>B1</div></div>`)
+
+    app.count++
+    await nextTick()
+    // test remounting a memoized tree
+    expect(serialize(app.$el)).toBe(`<div>3<div>A1</div><div>B1</div></div>`)
+  })
+
+  it('should invalidate based on keys', async () => {
+    class App extends Component {
+      foo = 1
+      bar = 1
+      render() {
+        return memoize(() => h('div', this.foo + this.bar), this, 0, [this.bar])
+      }
+    }
+
+    const app = renderIntsance(App)
+    expect(serialize(app.$el)).toBe(`<div>2</div>`)
+
+    app.foo++
+    await nextTick()
+    // should not update
+    expect(serialize(app.$el)).toBe(`<div>2</div>`)
+
+    app.bar++
+    await nextTick()
+    // should update now
+    expect(serialize(app.$el)).toBe(`<div>4</div>`)
+  })
+})