From ae1eb65528d005d9ef1d34e30576e28575e745f0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B8rgen=20Sverre=20Lien=20Sell=C3=A6g?=
 <jorgen@guut.org>
Date: Thu, 18 Mar 2021 14:24:30 +0100
Subject: [PATCH 1/3] fix crash of wds when trying to follow emacs lock files
 by ignoring them in file watcher.

closes https://github.com/facebook/create-react-app/issues/9056
---
 packages/react-dev-utils/ignoredFiles.js | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/packages/react-dev-utils/ignoredFiles.js b/packages/react-dev-utils/ignoredFiles.js
index 73a6e8bc5cf..1c95177d2c5 100644
--- a/packages/react-dev-utils/ignoredFiles.js
+++ b/packages/react-dev-utils/ignoredFiles.js
@@ -11,10 +11,15 @@ const path = require('path');
 const escape = require('escape-string-regexp');
 
 module.exports = function ignoredFiles(appSrc) {
-  return new RegExp(
-    `^(?!${escape(
-      path.normalize(appSrc + '/').replace(/[\\]+/g, '/')
-    )}).+/node_modules/`,
-    'g'
-  );
+  return [
+    new RegExp(
+      `^(?!${escape(
+        path.normalize(appSrc + '/').replace(/[\\]+/g, '/'),
+      )}).+/node_modules/`,
+      'g',
+    ),
+    '**/.#*',
+    '**/*~',
+    '**/#*#',
+  ];
 };

From 027b95b713f3244842076a2efb46c25d4d50a2a6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B8rgen=20Sverre=20Lien=20Sell=C3=A6g?=
 <jorgen.sellag@ibooking.no>
Date: Tue, 1 Jun 2021 16:54:13 +0200
Subject: [PATCH 2/3] update ignoredFiles test to use anymatch as it does in
 webpack as well

---
 .../__tests__/ignoredFiles.test.js            | 24 +++++++++++++------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/packages/react-dev-utils/__tests__/ignoredFiles.test.js b/packages/react-dev-utils/__tests__/ignoredFiles.test.js
index 6feed979797..83a2b9a42ce 100644
--- a/packages/react-dev-utils/__tests__/ignoredFiles.test.js
+++ b/packages/react-dev-utils/__tests__/ignoredFiles.test.js
@@ -9,11 +9,13 @@
 
 const ignoredFiles = require('../ignoredFiles');
 
+const anymatch = require('anymatch');
+
 describe('ignore watch files regex', () => {
   it('normal file', () => {
     const appSrc = '/root/src/';
-    const isIgnored = ignoredFiles(appSrc).test('/foo');
-    const isIgnoredInSrc = ignoredFiles(appSrc).test('/root/src/foo');
+    const isIgnored = anymatch(ignoredFiles(appSrc), '/foo');
+    const isIgnoredInSrc = anymatch(ignoredFiles(appSrc), '/root/src/foo');
 
     expect(isIgnored).toBe(false);
     expect(isIgnoredInSrc).toBe(false);
@@ -21,15 +23,19 @@ describe('ignore watch files regex', () => {
 
   it('node modules', () => {
     const appSrc = '/root/src/';
-    const isIgnored = ignoredFiles(appSrc).test('/root/node_modules/foo');
+    const isIgnored = anymatch(ignoredFiles(appSrc), '/root/node_modules/foo');
 
     expect(isIgnored).toBe(true);
   });
 
   it('node modules inside source directory', () => {
     const appSrc = '/root/src/';
-    const isIgnored = ignoredFiles(appSrc).test('/root/src/node_modules/foo');
-    const isIgnoredMoreThanOneLevel = ignoredFiles(appSrc).test(
+    const isIgnored = anymatch(
+      ignoredFiles(appSrc),
+      '/root/src/node_modules/foo'
+    );
+    const isIgnoredMoreThanOneLevel = anymatch(
+      ignoredFiles(appSrc),
       '/root/src/bar/node_modules/foo'
     );
 
@@ -39,7 +45,8 @@ describe('ignore watch files regex', () => {
 
   it('path contains source directory', () => {
     const appSrc = '/root/src/';
-    const isIgnored = ignoredFiles(appSrc).test(
+    const isIgnored = anymatch(
+      ignoredFiles(appSrc),
       '/bar/root/src/node_modules/foo'
     );
 
@@ -48,7 +55,10 @@ describe('ignore watch files regex', () => {
 
   it('path starts with source directory', () => {
     const appSrc = '/root/src/';
-    const isIgnored = ignoredFiles(appSrc).test('/root/src2/node_modules/foo');
+    const isIgnored = anymatch(
+      ignoredFiles(appSrc),
+      '/root/src2/node_modules/foo'
+    );
 
     expect(isIgnored).toBe(true);
   });

From 2074e1ef405b1405ab8d5857a37de43a363b54ca Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B8rgen=20Sverre=20Lien=20Sell=C3=A6g?=
 <jorgen.sellag@ibooking.no>
Date: Tue, 1 Jun 2021 16:58:15 +0200
Subject: [PATCH 3/3] add tests for ignore emacs case

---
 .../__tests__/ignoredFiles.test.js            | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/packages/react-dev-utils/__tests__/ignoredFiles.test.js b/packages/react-dev-utils/__tests__/ignoredFiles.test.js
index 83a2b9a42ce..03175d7ecee 100644
--- a/packages/react-dev-utils/__tests__/ignoredFiles.test.js
+++ b/packages/react-dev-utils/__tests__/ignoredFiles.test.js
@@ -62,4 +62,25 @@ describe('ignore watch files regex', () => {
 
     expect(isIgnored).toBe(true);
   });
+
+  it('ignores emacs temporary files', () => {
+    const appSrc = '/root/src/';
+    const isIgnored = anymatch(ignoredFiles(appSrc), 'file.txt~');
+
+    expect(isIgnored).toBe(true);
+  });
+
+  it('ignores emacs lock files', () => {
+    const appSrc = '/root/src/';
+    const isIgnored = anymatch(ignoredFiles(appSrc), '.#file.txt');
+
+    expect(isIgnored).toBe(true);
+  });
+
+  it('ignores emacs backup files', () => {
+    const appSrc = '/root/src/';
+    const isIgnored = anymatch(ignoredFiles(appSrc), '.#file.txt#');
+
+    expect(isIgnored).toBe(true);
+  });
 });