From 680a58a3a3a46fce0b3b1db0b0161331e81260f3 Mon Sep 17 00:00:00 2001
From: mad-jose <joset@yeswearemad.com>
Date: Fri, 6 Nov 2020 11:52:03 +0530
Subject: [PATCH 1/2] appTsConfig immutability handling by immer

---
 .../scripts/utils/verifyTypeScriptSetup.js           | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js b/packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js
index 04e6e4e0020..3872667045a 100644
--- a/packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js
+++ b/packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js
@@ -236,7 +236,9 @@ function verifyTypeScriptSetup() {
 
     if (suggested != null) {
       if (parsedCompilerOptions[option] === undefined) {
-        appTsConfig.compilerOptions[option] = suggested;
+        appTsConfig = immer(appTsConfig, config => {
+          config.compilerOptions[option] = suggested;
+        });
         messages.push(
           `${coloredOption} to be ${chalk.bold(
             'suggested'
@@ -244,7 +246,9 @@ function verifyTypeScriptSetup() {
         );
       }
     } else if (parsedCompilerOptions[option] !== valueToCheck) {
-      appTsConfig.compilerOptions[option] = value;
+      appTsConfig = immer(appTsConfig, config => {
+        config.compilerOptions[option] = value;
+      });
       messages.push(
         `${coloredOption} ${chalk.bold(
           valueToCheck == null ? 'must not' : 'must'
@@ -256,7 +260,9 @@ function verifyTypeScriptSetup() {
 
   // tsconfig will have the merged "include" and "exclude" by this point
   if (parsedTsConfig.include == null) {
-    appTsConfig.include = ['src'];
+    appTsConfig = immer(appTsConfig, config => {
+      config.include = ['src'];
+    });
     messages.push(
       `${chalk.cyan('include')} should be ${chalk.cyan.bold('src')}`
     );

From d61d3aaa1237f7eb47266143e231f2c6af587de3 Mon Sep 17 00:00:00 2001
From: mad-jose <44253495+josezone@users.noreply.github.com>
Date: Tue, 24 Nov 2020 06:36:17 +0530
Subject: [PATCH 2/2] Remove stringify

---
 .../scripts/utils/verifyTypeScriptSetup.js             | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js b/packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js
index 3872667045a..949f34ab7d2 100644
--- a/packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js
+++ b/packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js
@@ -218,15 +218,7 @@ function verifyTypeScriptSetup() {
   if (appTsConfig.compilerOptions == null) {
     appTsConfig.compilerOptions = {};
     firstTimeSetup = true;
-  } else {
-    // This is bug fix code of https://github.com/facebook/create-react-app/issues/9868
-    // Bellow code release variable from non-extensible and freeze status.
-    appTsConfig.compilerOptions = JSON.parse(JSON.stringify(appTsConfig.compilerOptions));
-
-    // Original appTsConfig.compilerOptions status
-    // Object.isExtensible(appTsConfig.compilerOptions) output: false
-    // Object.isFrozen(appTsConfig.compilerOptions) output: true
-  }
+  } 
 
   for (const option of Object.keys(compilerOptions)) {
     const { parsedValue, value, suggested, reason } = compilerOptions[option];