std: Provide types for React and ReactDOM (denoland/deno#4376)

Introduces `types` which is designed to provide types for common
libraries that are compatible with Deno.

types/README.md

@@ -0,0 +1,28 @@
+# std/types
+
+Contains types for popular external packages that are compatible with Deno.
+
+Because Deno only resolves fully qualified file names, type definitions that
+import other type definitions might not work with Deno. Also, when some type
+definition supply some global interfaces, they can conflict with Deno. The types
+located here have been validated to work with Deno.
+
+The types that are currently available:
+
+- `react.d.ts` - For React 16. Sources known to work well for Deno:
+  - Pika CDN: `https://cdn.pika.dev/_/react/v16`
+  - JSPM: `https://dev.jspm.io/react@16`
+- `react-dom.d.ts` - For ReactDOM 16. Sources known to work well for Deno:
+  - Pika CDN: `https://cdn.pika.dev/_/react-dom/v16`
+  - JSPM: `https://dev.jspm.io/react-dom@16`
+
+There are several ways these type definitions can be referenced. Likely the
+"best" way is that the CDN provider provides a header of `X-TypeScript-Types`
+which points to the type definitions. We are working to have this available, but
+currently you would need to use the compiler hint of `@deno-types`. For example
+to import React:
+
+```ts
+// @deno-types="https://deno.land/std/types/react.d.ts"
+import React from "https://cdn.pika.dev/_/react/v16";
+```

types/react-dom.d.ts

@@ -0,0 +1,125 @@
+// These types are adapted from
+// https://github.com/DefinitelyTyped/DefinitelyTyped to work under Deno.
+//
+// Type definitions for React (react-dom) 16.9
+// Project: http://facebook.github.io/react/
+// Definitions by: Asana <https://asana.com>
+//                 AssureSign <http://www.assuresign.com>
+//                 Microsoft <https://microsoft.com>
+//                 MartynasZilinskas <https://github.com/MartynasZilinskas>
+//                 Josh Rutherford <https://github.com/theruther4d>
+//                 Jessica Franco <https://github.com/Jessidhia>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.8
+
+// NOTE: Users of the `experimental` builds of React should add a reference
+// to 'react-dom/experimental' in their project. See experimental.d.ts's top comment
+// for reference and documentation on how exactly to do it.
+
+/* eslint-disable */
+
+export as namespace ReactDOM;
+
+import {
+  ReactInstance,
+  Component,
+  ComponentState,
+  ReactElement,
+  SFCElement,
+  CElement,
+  DOMAttributes,
+  DOMElement,
+  ReactNode,
+  ReactPortal
+} from "./react.d.ts";
+
+export function findDOMNode(
+  instance: ReactInstance | null | undefined
+): Element | null | Text;
+export function unmountComponentAtNode(container: Element): boolean;
+
+export function createPortal(
+  children: ReactNode,
+  container: Element,
+  key?: null | string
+): ReactPortal;
+
+export const version: string;
+export const render: Renderer;
+export const hydrate: Renderer;
+
+export function unstable_batchedUpdates<A, B>(
+  callback: (a: A, b: B) => any,
+  a: A,
+  b: B
+): void;
+export function unstable_batchedUpdates<A>(callback: (a: A) => any, a: A): void;
+export function unstable_batchedUpdates(callback: () => any): void;
+
+export function unstable_renderSubtreeIntoContainer<T extends Element>(
+  parentComponent: Component<any>,
+  element: DOMElement<DOMAttributes<T>, T>,
+  container: Element,
+  callback?: (element: T) => any
+): T;
+export function unstable_renderSubtreeIntoContainer<
+  P,
+  T extends Component<P, ComponentState>
+>(
+  parentComponent: Component<any>,
+  element: CElement<P, T>,
+  container: Element,
+  callback?: (component: T) => any
+): T;
+export function unstable_renderSubtreeIntoContainer<P>(
+  parentComponent: Component<any>,
+  element: ReactElement<P>,
+  container: Element,
+  callback?: (component?: Component<P, ComponentState> | Element) => any
+): Component<P, ComponentState> | Element | void;
+
+export interface Renderer {
+  // Deprecated(render): The return value is deprecated.
+  // In future releases the render function's return type will be void.
+
+  <T extends Element>(
+    element: DOMElement<DOMAttributes<T>, T>,
+    container: Element | null,
+    callback?: () => void
+  ): T;
+
+  (
+    element: Array<DOMElement<DOMAttributes<any>, any>>,
+    container: Element | null,
+    callback?: () => void
+  ): Element;
+
+  (
+    element: SFCElement<any> | Array<SFCElement<any>>,
+    container: Element | null,
+    callback?: () => void
+  ): void;
+
+  <P, T extends Component<P, ComponentState>>(
+    element: CElement<P, T>,
+    container: Element | null,
+    callback?: () => void
+  ): T;
+
+  (
+    element: Array<CElement<any, Component<any, ComponentState>>>,
+    container: Element | null,
+    callback?: () => void
+  ): Component<any, ComponentState>;
+
+  <P>(
+    element: ReactElement<P>,
+    container: Element | null,
+    callback?: () => void
+  ): Component<P, ComponentState> | Element | void;
+
+  (element: ReactElement[], container: Element | null, callback?: () => void):
+    | Component<any, ComponentState>
+    | Element
+    | void;
+}