From f71b4a0526509070732d2dc4ff5dddbcc8e984fa Mon Sep 17 00:00:00 2001
From: Clay Miller <clay@smockle.com>
Date: Sun, 27 Oct 2019 22:11:25 -0400
Subject: [PATCH] Make 'Omit' a distributive conditional type to support union
 prop types. Fixes #39300. (#39323)

---
 types/styled-components/index.d.ts     | 2 +-
 types/styled-components/test/index.tsx | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/types/styled-components/index.d.ts b/types/styled-components/index.d.ts
index 8faaa640bb..a483f96b05 100644
--- a/types/styled-components/index.d.ts
+++ b/types/styled-components/index.d.ts
@@ -346,7 +346,7 @@ export type ThemedCssFunction<T extends object> = BaseThemedCssFunction<
 >;
 
 // Helper type operators
-type Omit<T, K extends keyof T> = Pick<T, Exclude<keyof T, K>>;
+type Omit<T, K extends keyof T> = T extends any ? Pick<T, Exclude<keyof T, K>> : never;
 type WithOptionalTheme<P extends { theme?: T }, T> = Omit<P, "theme"> & {
     theme?: T;
 };
diff --git a/types/styled-components/test/index.tsx b/types/styled-components/test/index.tsx
index a2a8f7f1a4..eaa43ee491 100644
--- a/types/styled-components/test/index.tsx
+++ b/types/styled-components/test/index.tsx
@@ -1052,8 +1052,7 @@ function unionTest() {
         font-size: ${props => props.kind === 'book' ? 16 : 14}
     `;
 
-    // undesired, fix was reverted because of https://github.com/Microsoft/TypeScript/issues/30663
-    <StyledReadable kind="book" author="Hejlsberg" />; // $ExpectError
+    <StyledReadable kind="book" author="Hejlsberg" />;
     <StyledReadable kind="magazine" author="Hejlsberg" />; // $ExpectError
 }