feat(waitFor*): improve stacktrace for timeout errors (#492)

* feat(waitFor*): improve stacktrace for timeout errors

* Update src/wait-for.js

Co-Authored-By: Tim Deschryver <[email protected]>

* update snapshots

Co-authored-by: Tim Deschryver <[email protected]>

Closes #491

Author: Kent C. Dodds

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

@@ -141,6 +141,15 @@ test('rethrows non-testing-lib errors', () => {
   ).rejects.toBe(error)
 })
 
+test('logs timeout error when it times out', async () => {
+  const div = document.createElement('div')
+  await expect(
+    waitForElementToBeRemoved(() => div, {timeout: 1}),
+  ).rejects.toThrowErrorMatchingInlineSnapshot(
+    `"Timed out in waitForElementToBeRemoved."`,
+  )
+})
+
 test('accepts an element as an argument and waits for it to be removed from its top-most parent', async () => {
   const {queryByTestId} = renderIntoDocument(`
     <div data-testid="div"></div>

src/__tests__/wait-for.js

@@ -21,3 +21,14 @@ test('can timeout after the given timeout time', async () => {
   ).catch(e => e)
   expect(result).toBe(error)
 })
+
+test('uses generic error if there was no last error', async () => {
+  const result = await waitFor(
+    () => {
+      // eslint-disable-next-line no-throw-literal
+      throw undefined
+    },
+    {timeout: 8, interval: 5},
+  ).catch(e => e)
+  expect(result).toMatchInlineSnapshot(`[Error: Timed out in waitFor.]`)
+})

src/wait-for-element-to-be-removed.js

@@ -13,8 +13,9 @@ function initialCheck(elements) {
 }
 
 async function waitForElementToBeRemoved(callback, options) {
+  // created here so we get a nice stacktrace
+  const timeoutError = new Error('Timed out in waitForElementToBeRemoved.')
   if (typeof callback !== 'function') {
-    // await waitForElementToBeRemoved(getAllByText('Hello'))
     initialCheck(callback)
     const elements = Array.isArray(callback) ? callback : [callback]
     const getRemainingElements = elements.map(element => {
@@ -38,7 +39,7 @@ async function waitForElementToBeRemoved(callback, options) {
       throw error
     }
     if (!isRemoved(result)) {
-      throw new Error('Timed out in waitForElementToBeRemoved.')
+      throw timeoutError
     }
     return true
   }, options)

src/wait-for.js

@@ -22,6 +22,8 @@ function waitFor(
     },
   } = {},
 ) {
+  // created here so we get a nice stacktrace
+  const timedOutError = new Error('Timed out in waitFor.')
   if (interval < 1) interval = 1
   return new Promise((resolve, reject) => {
     let lastError
@@ -57,7 +59,7 @@ function waitFor(
     }
 
     function onTimeout() {
-      onDone(lastError || new Error('Timed out in wait.'), null)
+      onDone(lastError || timedOutError, null)
     }
   })
 }