test: the SpringContext component

Author: aleclarson

packages/core/src/SpringContext.test.tsx

@@ -0,0 +1,106 @@
+import React from 'react'
+import { render, RenderResult } from '@testing-library/react'
+import { SpringContext } from './SpringContext'
+import { SpringValue } from './SpringValue'
+import { useSpring } from './hooks'
+
+describe('SpringContext', () => {
+  let t: SpringValue<number>
+
+  const Child = () => {
+    t = useSpring({ t: 1, from: { t: 0 } }).t
+    return null
+  }
+
+  const update = createUpdater(props => (
+    <SpringContext {...props}>
+      <Child />
+    </SpringContext>
+  ))
+
+  it('can cancel current animations', () => {
+    update({})
+    mockRaf.step()
+    expect(t.idle).toBeFalsy()
+    update({ cancel: true })
+    expect(t.idle).toBeTruthy()
+  })
+  it('can cancel future animations', async () => {
+    update({ cancel: true })
+    expect(t.idle).toBeTruthy()
+    const { cancelled } = await t.start(100)
+    expect(cancelled).toBeTruthy()
+    expect(t.idle).toBeTruthy()
+    expect(t.goal).toBe(0)
+  })
+
+  it('can pause current animations', () => {
+    update({})
+    mockRaf.step()
+    expect(t.idle).toBeFalsy()
+
+    update({ pause: true })
+    expect(t.idle).toBeTruthy()
+    expect(t.goal).toBe(1)
+
+    update({ pause: false })
+    expect(t.idle).toBeFalsy()
+    expect(t.goal).toBe(1)
+  })
+  it('can pause future animations', () => {
+    // Paused right away.
+    update({ pause: true })
+    expect(t.idle).toBeTruthy()
+    expect(t.goal).toBeUndefined()
+
+    // This update is paused too.
+    t.start(2)
+    expect(t.idle).toBeTruthy()
+    expect(t.goal).toBeUndefined()
+
+    // Let it roll.
+    update({ pause: false })
+    expect(t.idle).toBeFalsy()
+    // The `goal` is not 2, because the `useSpring` hook is
+    // executed by the SpringContext update.
+    expect(t.goal).toBe(1)
+  })
+
+  it('can make current animations immediate', () => {
+    update({})
+    mockRaf.step()
+    expect(t.idle).toBeFalsy()
+
+    update({ immediate: true })
+    mockRaf.step()
+
+    expect(t.idle).toBeTruthy()
+    expect(t.get()).toBe(1)
+  })
+  it('can make future animations immediate', () => {
+    update({ immediate: true })
+    mockRaf.step()
+
+    expect(t.idle).toBeTruthy()
+    expect(t.get()).toBe(1)
+
+    t.start(2)
+    mockRaf.step()
+
+    expect(t.idle).toBeTruthy()
+    expect(t.get()).toBe(2)
+  })
+})
+
+function createUpdater(Component: React.ComponentType<SpringContext>) {
+  let result: RenderResult | undefined
+  afterEach(() => {
+    result = undefined
+  })
+  return (props: SpringContext) => {
+    const elem = <Component {...props} />
+    if (result) result.rerender(elem)
+    else result = render(elem)
+    return result
+  }
+}