From 4dd9510a504875fb79a399d468e8f39e892af617 Mon Sep 17 00:00:00 2001
From: Jessica <jessicamfranco3@gmail.com>
Date: Fri, 23 Nov 2018 15:05:46 +0900
Subject: [PATCH] Strengthen type of ReactType to also validate intrinsic
 elements

---
 types/react/index.d.ts   | 12 ++++++++----
 types/react/test/tsx.tsx |  7 +++++++
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/types/react/index.d.ts b/types/react/index.d.ts
index 25f3c710ae..522a106944 100644
--- a/types/react/index.d.ts
+++ b/types/react/index.d.ts
@@ -50,7 +50,11 @@ declare namespace React {
     // React Elements
     // ----------------------------------------------------------------------
 
-    type ReactType<P = any> = string | ComponentType<P>;
+    type ReactType<P = any> =
+        {
+            [K in keyof JSX.IntrinsicElements]: P extends JSX.IntrinsicElements[K] ? K : never
+        }[keyof JSX.IntrinsicElements] |
+        ComponentType<P>;
     type ComponentType<P = {}> = ComponentClass<P> | FunctionComponent<P>;
 
     type Key = string | number;
@@ -713,17 +717,17 @@ declare namespace React {
      * NOTE: prefer ComponentPropsWithRef, if the ref is forwarded,
      * or ComponentPropsWithoutRef when refs are not supported.
      */
-    type ComponentProps<T extends keyof JSX.IntrinsicElements | ComponentType<any>> =
+    type ComponentProps<T extends ReactType> =
         T extends ComponentType<infer P>
             ? P
             : T extends keyof JSX.IntrinsicElements
                 ? JSX.IntrinsicElements[T]
                 : {};
-    type ComponentPropsWithRef<T extends keyof JSX.IntrinsicElements | ComponentType<any>> =
+    type ComponentPropsWithRef<T extends ReactType> =
         T extends ComponentClass<infer P>
             ? PropsWithoutRef<P> & RefAttributes<InstanceType<T>>
             : PropsWithRef<ComponentProps<T>>;
-    type ComponentPropsWithoutRef<T extends keyof JSX.IntrinsicElements | ComponentType<any>> =
+    type ComponentPropsWithoutRef<T extends ReactType> =
         PropsWithoutRef<ComponentProps<T>>;
 
     // will show `Memo(${Component.displayName || Component.name})` in devtools by default,
diff --git a/types/react/test/tsx.tsx b/types/react/test/tsx.tsx
index f344fb2838..a8ca2ae1ea 100644
--- a/types/react/test/tsx.tsx
+++ b/types/react/test/tsx.tsx
@@ -325,3 +325,10 @@ type ImgPropsWithRefRef = ImgPropsWithRef['ref'];
 type ImgPropsWithoutRef = React.ComponentPropsWithoutRef<'img'>;
 // $ExpectType false
 type ImgPropsHasRef = 'ref' extends keyof ImgPropsWithoutRef ? true : false;
+
+const HasClassName: React.ReactType<{ className?: string }> = 'a';
+const HasFoo: React.ReactType<{ foo: boolean }> = 'a'; // $ExpectError
+const HasFoo2: React.ReactType<{ foo: boolean }> = (props: { foo: boolean }) => null;
+const HasFoo3: React.ReactType<{ foo: boolean }> = (props: { foo: string }) => null; // $ExpectError
+const HasHref: React.ReactType<{ href?: string }> = 'a';
+const HasHref2: React.ReactType<{ href?: string }> = 'div'; // $ExpectError