From 99b5cb9eb262910f63f408f8fd0f45009f24260c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kr=C3=A6n=20Hansen?= <kraen.hansen@mongodb.com>
Date: Fri, 2 Feb 2024 09:54:12 +0100
Subject: [PATCH 1/2] Adding a `injectProjectRootAsWatchFolder` argument and
 fallback watchFolders to an empty array

---
 packages/metro-config/src/loadConfig.js | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/packages/metro-config/src/loadConfig.js b/packages/metro-config/src/loadConfig.js
index d2c65b0438..7e32b3d63a 100644
--- a/packages/metro-config/src/loadConfig.js
+++ b/packages/metro-config/src/loadConfig.js
@@ -290,13 +290,15 @@ function overrideConfigWithArguments(
 
 /**
  * Load the metro configuration from disk
- * @param  {object} argv                    Arguments coming from the CLI, can be empty
- * @param  {object} defaultConfigOverrides  A configuration that can override the default config
- * @return {object}                         Configuration returned
+ * @param  {object}  argv                           Arguments coming from the CLI, can be empty
+ * @param  {object}  defaultConfigOverrides         A configuration that can override the default config
+ * @param  {boolean} injectProjectRootAsWatchFolder Will ensure `projectRoot` is present in the `watchFolders`
+ * @return {object}                                 Configuration returned
  */
 async function loadConfig(
   argvInput?: YargArguments = {},
   defaultConfigOverrides?: InputConfigT = {},
+  injectProjectRootAsWatchFolder?: boolean = true,
 ): Promise<ConfigT> {
   const argv = {...argvInput, config: overrideArgument(argvInput.config)};
 
@@ -321,10 +323,12 @@ async function loadConfig(
 
   const overriddenConfig: {[string]: mixed} = {};
 
-  overriddenConfig.watchFolders = [
-    configWithArgs.projectRoot,
-    ...configWithArgs.watchFolders,
-  ];
+  if (injectProjectRootAsWatchFolder) {
+    overriddenConfig.watchFolders = [
+      configWithArgs.projectRoot,
+      ...(configWithArgs.watchFolders ?? []),
+    ];
+  }
 
   // Set the watchfolders to include the projectRoot, as Metro assumes that is
   // the case

From e6de60117ea1e099cb417131d57de52250338ca2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kr=C3=A6n=20Hansen?= <kraen.hansen@mongodb.com>
Date: Fri, 2 Feb 2024 09:54:18 +0100
Subject: [PATCH 2/2] Adding a test

---
 .../metro-config/src/__tests__/loadConfig-test.js | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/packages/metro-config/src/__tests__/loadConfig-test.js b/packages/metro-config/src/__tests__/loadConfig-test.js
index 247913f8a7..ebf6355aa5 100644
--- a/packages/metro-config/src/__tests__/loadConfig-test.js
+++ b/packages/metro-config/src/__tests__/loadConfig-test.js
@@ -166,6 +166,21 @@ describe('loadConfig', () => {
     expect(prettyFormat(result)).toEqual(prettyFormat(defaultConfig));
   });
 
+  it('does not inject projectRoot into watchFolders when called with a third `false` argument', async () => {
+    cosmiconfig.setReturnNull(true);
+
+    const result = await loadConfig(
+      {cwd: process.cwd()},
+      {watchFolders: undefined},
+      false,
+    );
+    const defaultConfig = {
+      ...(await getDefaultConfig(process.cwd())),
+      watchFolders: undefined,
+    };
+    expect(prettyFormat(result)).toEqual(prettyFormat(defaultConfig));
+  });
+
   it('validates config for server', async () => {
     expect.assertions(1);
     const config = (defaultConfig: any) => ({