From 72b0220100388b686ad78c547d83a9d9f5c89222 Mon Sep 17 00:00:00 2001
From: Naresh Bhatia <naresh.archfirst@gmail.com>
Date: Wed, 13 Mar 2019 10:56:48 -0400
Subject: [PATCH 1/2] add support for Jest's moduleNameMapper configuration

Allow merging of external `moduleNameMapper` configuration with the internal configuration required by react-scripts.
---
 packages/react-scripts/scripts/utils/createJestConfig.js | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/packages/react-scripts/scripts/utils/createJestConfig.js b/packages/react-scripts/scripts/utils/createJestConfig.js
index 5294220b1fe..ad16984a0f3 100644
--- a/packages/react-scripts/scripts/utils/createJestConfig.js
+++ b/packages/react-scripts/scripts/utils/createJestConfig.js
@@ -79,15 +79,22 @@ module.exports = (resolve, rootDir, isEjecting) => {
     'coverageThreshold',
     'globalSetup',
     'globalTeardown',
+    'moduleNameMapper',
     'resetMocks',
     'resetModules',
     'snapshotSerializers',
     'watchPathIgnorePatterns',
   ];
+  const mergedKeys = ['moduleNameMapper'];
   if (overrides) {
     supportedKeys.forEach(key => {
       if (overrides.hasOwnProperty(key)) {
-        config[key] = overrides[key];
+        if (mergedKeys.includes(key)) {
+          // Allow overrides[key] to override internal configuration
+          config[key] = Object.assign(config[key], overrides[key]);
+        } else {
+          config[key] = overrides[key];
+        }
         delete overrides[key];
       }
     });

From 1ae48cac16f3ec74d5165c16f0119157a832edeb Mon Sep 17 00:00:00 2001
From: Naresh Bhatia <naresh.archfirst@gmail.com>
Date: Wed, 13 Mar 2019 11:37:50 -0400
Subject: [PATCH 2/2] Updated docs for running tests.

---
 docusaurus/docs/running-tests.md | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/docusaurus/docs/running-tests.md b/docusaurus/docs/running-tests.md
index 5f93a391771..96c84abd254 100644
--- a/docusaurus/docs/running-tests.md
+++ b/docusaurus/docs/running-tests.md
@@ -279,7 +279,13 @@ Supported overrides:
 - [`collectCoverageFrom`](https://jestjs.io/docs/en/configuration.html#collectcoveragefrom-array)
 - [`coverageReporters`](https://jestjs.io/docs/en/configuration.html#coveragereporters-array-string)
 - [`coverageThreshold`](https://jestjs.io/docs/en/configuration.html#coveragethreshold-object)
+- [`globalSetup`](https://jestjs.io/docs/en/configuration.html#globalsetup-string)
+- [`globalTeardown`](https://jestjs.io/docs/en/configuration.html#globalteardown-string)
+- [`moduleNameMapper`](https://jestjs.io/docs/en/configuration.html#modulenamemapper-object-string-string)
+- [`resetMocks`](https://jestjs.io/docs/en/configuration.html#resetmocks-boolean)
+- [`resetModules`](https://jestjs.io/docs/en/configuration.html#resetmodules-boolean)
 - [`snapshotSerializers`](https://jestjs.io/docs/en/configuration.html#snapshotserializers-array-string)
+- [`watchPathIgnorePatterns`](https://jestjs.io/docs/en/configuration.html#watchpathignorepatterns-array-string)
 
 Example package.json: