From 4e71a30969d74073309d0350be55cadb84ae43ff Mon Sep 17 00:00:00 2001
From: Jordan Brown <jmbrown@fb.com>
Date: Thu, 2 Jan 2020 09:57:36 -0800
Subject: [PATCH] Fix return type of StyleSheet.create to be the identity
 function

Summary:
Changes the return type of StyleSheet.create to `$ReadOnly<S>`. At runtime, it just freezes the fields in dev mode and is the identity function otherwise. This cause 423 errors due to the wrong props being passed to different styles: P124372727

I went over errors at random with Eli to get confidence in the change.

Changelog:
[General][Fixed] Fix return type of StyleSheet.create

Reviewed By: zackargyle, TheSavior

Differential Revision: D19218817

fbshipit-source-id: b7aa10700f8333372c9f0bd61bfbef371caadf97
---
 Libraries/LogBox/UI/LogBoxNotification.js | 2 ++
 Libraries/StyleSheet/StyleSheet.js        | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/Libraries/LogBox/UI/LogBoxNotification.js b/Libraries/LogBox/UI/LogBoxNotification.js
index eb2b52a58544c6..e2623b2694435f 100644
--- a/Libraries/LogBox/UI/LogBoxNotification.js
+++ b/Libraries/LogBox/UI/LogBoxNotification.js
@@ -60,6 +60,8 @@ function LogBoxLogNotification(props: Props): React.Node {
 function CountBadge(props) {
   return (
     <View style={countStyles.outside}>
+      {/* $FlowFixMe(>=0.114.0) This suppression was added when fixing the type
+       * of `StyleSheet.create`. Remove this comment to see the error. */}
       <View style={[countStyles.inside, countStyles[props.level]]}>
         <Text style={countStyles.text}>
           {props.count <= 1 ? '!' : props.count}
diff --git a/Libraries/StyleSheet/StyleSheet.js b/Libraries/StyleSheet/StyleSheet.js
index 1a1fea49e4fd3e..54094d8bd4929e 100644
--- a/Libraries/StyleSheet/StyleSheet.js
+++ b/Libraries/StyleSheet/StyleSheet.js
@@ -347,7 +347,7 @@ module.exports = {
   /**
    * Creates a StyleSheet style reference from the given object.
    */
-  create<+S: ____Styles_Internal>(obj: S): $ObjMap<S, (Object) => any> {
+  create<+S: ____Styles_Internal>(obj: S): $ReadOnly<S> {
     // TODO: This should return S as the return type. But first,
     // we need to codemod all the callsites that are typing this
     // return value as a number (even though it was opaque).