RN: Add react-test-renderer Flow Definition

Summary:
Adds the `react-test-renderer` Flow definition (via `flow-typed`) so it can be used from tests with Flow enabled.

Changelog:
[Internal]

Reviewed By: TheSavior

Differential Revision: D28922375

fbshipit-source-id: 9b1be69f1b281bb3c248ca272cf2527baf154e2a

Author: yungsters

.eslintrc

@@ -21,6 +21,14 @@
         "@react-native/codegen/react-native-modules": 2
       }
     },
+    {
+      "files": [
+        "flow-typed/**/*.js",
+      ],
+      "rules": {
+        quotes: 0
+      }
+    },
     {
       "files": [
         "**/__fixtures__/**/*.js",

flow-typed/npm/react-test-renderer_v16.x.x.js

@@ -0,0 +1,79 @@
+// flow-typed signature: 7bac6c05f7415881918d3d510109e739
+// flow-typed version: fce74493f0/react-test-renderer_v16.x.x/flow_>=v0.104.x
+
+// Type definitions for react-test-renderer 16.x.x
+// Ported from: https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/react-test-renderer
+
+type ReactComponentInstance = React$Component<any>;
+
+type ReactTestRendererJSON = {
+  type: string,
+  props: { [propName: string]: any, ... },
+  children: null | ReactTestRendererJSON[],
+  ...
+};
+
+type ReactTestRendererTree = ReactTestRendererJSON & {
+  nodeType: "component" | "host",
+  instance: ?ReactComponentInstance,
+  rendered: null | ReactTestRendererTree,
+  ...
+};
+
+type ReactTestInstance = {
+  instance: ?ReactComponentInstance,
+  type: string,
+  props: { [propName: string]: any, ... },
+  parent: null | ReactTestInstance,
+  children: Array<ReactTestInstance | string>,
+  find(predicate: (node: ReactTestInstance) => boolean): ReactTestInstance,
+  findByType(type: React$ElementType): ReactTestInstance,
+  findByProps(props: { [propName: string]: any, ... }): ReactTestInstance,
+  findAll(
+    predicate: (node: ReactTestInstance) => boolean,
+    options?: { deep: boolean, ... }
+  ): ReactTestInstance[],
+  findAllByType(
+    type: React$ElementType,
+    options?: { deep: boolean, ... }
+  ): ReactTestInstance[],
+  findAllByProps(
+    props: { [propName: string]: any, ... },
+    options?: { deep: boolean, ... }
+  ): ReactTestInstance[],
+  ...
+};
+
+type TestRendererOptions = { createNodeMock(element: React$Element<any>): any, ... };
+
+declare module "react-test-renderer" {
+  declare export type ReactTestRenderer = {
+    toJSON(): null | ReactTestRendererJSON,
+    toTree(): null | ReactTestRendererTree,
+    unmount(nextElement?: React$Element<any>): void,
+    update(nextElement: React$Element<any>): void,
+    getInstance(): ?ReactComponentInstance,
+    root: ReactTestInstance,
+    ...
+  };
+
+  declare type Thenable = { then(resolve: () => mixed, reject?: () => mixed): mixed, ... };
+
+  declare function create(
+    nextElement: React$Element<any>,
+    options?: TestRendererOptions
+  ): ReactTestRenderer;
+
+  declare function act(callback: () => void | Promise<void>): Thenable;
+}
+
+declare module "react-test-renderer/shallow" {
+  declare export default class ShallowRenderer {
+    static createRenderer(): ShallowRenderer;
+    getMountedInstance(): ReactTestInstance;
+    getRenderOutput<E: React$Element<any>>(): E;
+    getRenderOutput(): React$Element<any>;
+    render(element: React$Element<any>, context?: any): void;
+    unmount(): void;
+  }
+}