From 7e39453d02aae3d28adcfdc908464f88abca5170 Mon Sep 17 00:00:00 2001
From: Andrew Cherniavskii <andrew.cherniavskii@gmail.com>
Date: Sat, 29 Feb 2020 13:43:43 +0100
Subject: [PATCH 1/3] test garbage collection of queries without data

---
 src/tests/useQuery.test.js | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/src/tests/useQuery.test.js b/src/tests/useQuery.test.js
index 4e69a41c4c..4e8a0bff05 100644
--- a/src/tests/useQuery.test.js
+++ b/src/tests/useQuery.test.js
@@ -1,4 +1,4 @@
-import { cleanup, render, act, waitForElement } from '@testing-library/react'
+import { cleanup, render, act, waitForElement, fireEvent } from '@testing-library/react'
 import * as React from 'react'
 
 import { useQuery, queryCache, statusLoading, statusSuccess } from '../index'
@@ -226,4 +226,39 @@ describe('useQuery', () => {
 
     expect(queryFn).toHaveBeenCalledTimes(2)
   })
+
+  it('should garbage collect queries without data immediately', async () => {
+    function Page() {
+      const [filter, setFilter] = React.useState('');
+      const { data } = useQuery(['todos', { filter }], async (key, { filter } = {}) => {
+        await sleep(1000);
+        return `todo ${filter}`;
+      })
+
+      return (
+        <div>
+          <div>{data}</div>
+          <button onClick={() => setFilter(filter + 'a')}>update</button>
+        </div>
+      )
+    }
+
+    const rendered = render(<Page />)
+
+    await waitForElement(() => rendered.getByText('update'))
+
+    fireEvent.click(rendered.getByText('update'))
+    fireEvent.click(rendered.getByText('update'))
+    fireEvent.click(rendered.getByText('update'))
+    fireEvent.click(rendered.getByText('update'))
+
+    expect(Object.keys(queryCache.queries).length).toEqual(5)
+
+    // wait for garbage collection
+    await sleep(0)
+
+    expect(Object.keys(queryCache.queries).length).toEqual(1)
+
+    await waitForElement(() => rendered.getByText('todo aaaa'));
+  })
 })

From 5f2778436135946f0157d67b187fe7a60560aacf Mon Sep 17 00:00:00 2001
From: Andrew Cherniavskii <andrew.cherniavskii@gmail.com>
Date: Sat, 29 Feb 2020 13:45:34 +0100
Subject: [PATCH 2/3] format code

---
 src/tests/useQuery.test.js | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/src/tests/useQuery.test.js b/src/tests/useQuery.test.js
index 4e8a0bff05..f0d8a2b554 100644
--- a/src/tests/useQuery.test.js
+++ b/src/tests/useQuery.test.js
@@ -1,4 +1,10 @@
-import { cleanup, render, act, waitForElement, fireEvent } from '@testing-library/react'
+import {
+  cleanup,
+  render,
+  act,
+  waitForElement,
+  fireEvent,
+} from '@testing-library/react'
 import * as React from 'react'
 
 import { useQuery, queryCache, statusLoading, statusSuccess } from '../index'
@@ -229,11 +235,14 @@ describe('useQuery', () => {
 
   it('should garbage collect queries without data immediately', async () => {
     function Page() {
-      const [filter, setFilter] = React.useState('');
-      const { data } = useQuery(['todos', { filter }], async (key, { filter } = {}) => {
-        await sleep(1000);
-        return `todo ${filter}`;
-      })
+      const [filter, setFilter] = React.useState('')
+      const { data } = useQuery(
+        ['todos', { filter }],
+        async (key, { filter } = {}) => {
+          await sleep(1000)
+          return `todo ${filter}`
+        }
+      )
 
       return (
         <div>
@@ -259,6 +268,6 @@ describe('useQuery', () => {
 
     expect(Object.keys(queryCache.queries).length).toEqual(1)
 
-    await waitForElement(() => rendered.getByText('todo aaaa'));
+    await waitForElement(() => rendered.getByText('todo aaaa'))
   })
 })

From 387386d6320c5cb12e9111da013817ba7a9b7cec Mon Sep 17 00:00:00 2001
From: Andrew Cherniavskii <andrew.cherniavskii@gmail.com>
Date: Sat, 29 Feb 2020 13:48:02 +0100
Subject: [PATCH 3/3] do not use sleep to wait for garbage collection

setTimeout is not reliable, so it's better to avoid it
---
 src/tests/useQuery.test.js | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/src/tests/useQuery.test.js b/src/tests/useQuery.test.js
index f0d8a2b554..10bbfb5d0e 100644
--- a/src/tests/useQuery.test.js
+++ b/src/tests/useQuery.test.js
@@ -263,11 +263,8 @@ describe('useQuery', () => {
 
     expect(Object.keys(queryCache.queries).length).toEqual(5)
 
-    // wait for garbage collection
-    await sleep(0)
+    await waitForElement(() => rendered.getByText('todo aaaa'))
 
     expect(Object.keys(queryCache.queries).length).toEqual(1)
-
-    await waitForElement(() => rendered.getByText('todo aaaa'))
   })
 })