test: improve tests for wait-for-element-to-be-removed

Author: Kent C. Dodds

src/__tests__/helpers/document.js

@@ -4,6 +4,7 @@ if (typeof window === 'undefined') {
   const {JSDOM} = require('jsdom')
   const dom = new JSDOM()
   testWindow = dom.window
+  global.window = testWindow
 }
 
 module.exports = testWindow.document

src/__tests__/wait-for-element-to-be-removed.fake-timers.js

@@ -0,0 +1,45 @@
+import 'jest-dom/extend-expect'
+import {waitForElementToBeRemoved} from '../'
+import {render} from './helpers/test-utils'
+
+jest.useFakeTimers()
+
+// const skipSomeTimeForMutationObserver = (delayMs = 50) => {
+//   jest.advanceTimersByTime(delayMs)
+//   jest.runAllImmediates()
+// }
+
+test('requires a function as the first parameter', () => {
+  return expect(
+    waitForElementToBeRemoved(),
+  ).rejects.toThrowErrorMatchingInlineSnapshot(
+    `"waitForElementToBeRemoved requires a function as the first parameter"`,
+  )
+})
+
+test('requires an element to exist first', () => {
+  return expect(
+    waitForElementToBeRemoved(() => null),
+  ).rejects.toThrowErrorMatchingInlineSnapshot(
+    `"The callback function which was passed did not return an element or non-empty array of elements. waitForElementToBeRemoved requires that the element(s) exist before waiting for removal."`,
+  )
+})
+
+test('requires an unempty array of elements to exist first', () => {
+  return expect(
+    waitForElementToBeRemoved(() => []),
+  ).rejects.toThrowErrorMatchingInlineSnapshot(
+    `"The callback function which was passed did not return an element or non-empty array of elements. waitForElementToBeRemoved requires that the element(s) exist before waiting for removal."`,
+  )
+})
+
+test('times out after 4500ms by default', () => {
+  const {container} = render(`<div></div>`)
+  const promise = expect(
+    waitForElementToBeRemoved(() => container),
+  ).rejects.toThrowErrorMatchingInlineSnapshot(
+    `"Timed out in waitForElementToBeRemoved."`,
+  )
+  jest.advanceTimersByTime(4501)
+  return promise
+})