diff --git a/types/co/co-tests.ts b/types/co/co-tests.ts
new file mode 100644
index 0000000000..159a2e90fb
--- /dev/null
+++ b/types/co/co-tests.ts
@@ -0,0 +1,30 @@
+import co = require('co');
+
+function* gen(num: number, str: string, arr: number[], obj: object, fun: () => void) {
+    return num;
+}
+
+co(gen, 42, 'forty-two', [42], { value: 42 }, () => {})
+    .then((num: number) => {}, (err: Error) => {})
+    .catch((err: Error) => {});
+
+co.default(gen, 42, 'forty-two', [42], { value: 42 }, () => {})
+    .then((num: number) => {}, (err: Error) => {})
+    .catch((err: Error) => {});
+
+co.co(gen, 42, 'forty-two', [42], { value: 42 }, () => {})
+    .then((num: number) => {}, (err: Error) => {})
+    .catch((err: Error) => {});
+
+co.wrap(gen)(42, 'forty-two', [42], { value: 42 }, () => {})
+    .then((num: number) => {}, (err: Error) => {})
+    .catch((err: Error) => {});
+
+// $ExpectError
+co(gen, 42, 'forty-two', [42], { value: 42 }, () => {}).then((str: string) => {});
+
+// $ExpectError
+co.wrap(gen)();
+
+// $ExpectError
+co.wrap(gen)('forty-two');
diff --git a/types/co/index.d.ts b/types/co/index.d.ts
new file mode 100644
index 0000000000..958c222a14
--- /dev/null
+++ b/types/co/index.d.ts
@@ -0,0 +1,18 @@
+// Type definitions for co 4.6
+// Project: https://github.com/tj/co#readme
+// Definitions by: Doniyor Aliyev <https://github.com/doniyor2109>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 3.1
+
+type ExtractType<T> = T extends IterableIterator<infer R> ? R : never;
+
+interface Co {
+    <F extends (...args: any[]) => Generator>(fn: F, ...args: Parameters<F>): Promise<ExtractType<ReturnType<F>>>;
+    default: Co;
+    co: Co;
+    wrap: <F extends (...args: any[]) => Generator>(fn: F) => (...args: Parameters<F>) => Promise<ExtractType<ReturnType<F>>>;
+}
+
+declare const co: Co;
+
+export = co;
diff --git a/types/co/tsconfig.json b/types/co/tsconfig.json
new file mode 100644
index 0000000000..bc5a88eb32
--- /dev/null
+++ b/types/co/tsconfig.json
@@ -0,0 +1,23 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": true,
+        "strictFunctionTypes": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "co-tests.ts"
+    ]
+}
diff --git a/types/co/tslint.json b/types/co/tslint.json
new file mode 100644
index 0000000000..3db14f85ea
--- /dev/null
+++ b/types/co/tslint.json
@@ -0,0 +1 @@
+{ "extends": "dtslint/dt.json" }
diff --git a/types/jest/index.d.ts b/types/jest/index.d.ts
index 29b3210cc2..f0382d2cb5 100644
--- a/types/jest/index.d.ts
+++ b/types/jest/index.d.ts
@@ -978,20 +978,29 @@ declare namespace jest {
     }
 
     /**
-     * Represents the result of a single call to a mock function.
+     * Represents the result of a single call to a mock function with a return value.
      */
-    interface MockResult {
-        /**
-         * True if the function threw.
-         * False if the function returned.
-         */
-        isThrow: boolean;
-        /**
-         * The value that was either thrown or returned by the function.
-         */
+    interface MockResultReturn<T> {
+        type: 'return';
+        value: T;
+    }
+    /**
+     * Represents the result of a single incomplete call to a mock function.
+     */
+    interface MockResultIncomplete {
+        type: 'incomplete';
+        value: undefined;
+    }
+    /**
+     * Represents the result of a single call to a mock function with a thrown error.
+     */
+    interface MockResultThrow {
+        type: 'throw';
         value: any;
     }
 
+    type MockResult<T> = MockResultReturn<T> | MockResultThrow | MockResultIncomplete;
+
     interface MockContext<T, Y extends any[]> {
         calls: Y[];
         instances: T[];
@@ -999,7 +1008,7 @@ declare namespace jest {
         /**
          * List of results of calls to the mock function.
          */
-        results: MockResult[];
+        results: Array<MockResult<T>>;
     }
 }
 
diff --git a/types/jest/jest-tests.ts b/types/jest/jest-tests.ts
index 11b3752a0a..69e68ab6f7 100644
--- a/types/jest/jest-tests.ts
+++ b/types/jest/jest-tests.ts
@@ -316,7 +316,7 @@ interface TestApi {
     test(x: number): string;
 }
 // $ExpectType Mock<string, [number]>
-const mock12 = jest.fn<ReturnType<TestApi["test"]>, ArgsType<TestApi["test"]>>();
+const mock12 = jest.fn<ReturnType<TestApi["test"]>, jest.ArgsType<TestApi["test"]>>();
 
 // $ExpectType number
 mock1('test');
@@ -485,6 +485,19 @@ mocked.test4.mockRejectedValue(new Error());
 // $ExpectError
 mocked.test4.mockRejectedValueOnce(new Error());
 
+const mockResult = jest.fn(() => 1).mock.results[0];
+switch (mockResult.type) {
+    case 'return':
+        mockResult.value; // $ExpectType number
+        break;
+    case 'incomplete':
+        mockResult.value; // $ExpectType undefined
+        break;
+    case 'throw':
+        mockResult.value; // $ExpectType any
+        break;
+}
+
 /* Snapshot serialization */
 
 const snapshotSerializerPlugin: jest.SnapshotSerializerPlugin = {
diff --git a/types/react-dom/index.d.ts b/types/react-dom/index.d.ts
index f81bbf4021..19c842f5a2 100644
--- a/types/react-dom/index.d.ts
+++ b/types/react-dom/index.d.ts
@@ -17,7 +17,7 @@ import {
     DOMAttributes, DOMElement, ReactNode, ReactPortal
 } from 'react';
 
-export function findDOMNode(instance: ReactInstance): Element | null | Text;
+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;
diff --git a/types/react-dom/react-dom-tests.tsx b/types/react-dom/react-dom-tests.tsx
index 46274e3ffd..20bfda53ea 100644
--- a/types/react-dom/react-dom-tests.tsx
+++ b/types/react-dom/react-dom-tests.tsx
@@ -30,6 +30,8 @@ describe('ReactDOM', () => {
         const rootElement = document.createElement('div');
         ReactDOM.render(React.createElement('div'), rootElement);
         ReactDOM.findDOMNode(rootElement);
+        ReactDOM.findDOMNode(null);
+        ReactDOM.findDOMNode(undefined);
     });
 
     it('createPortal', () => {
diff --git a/types/react-dom/v15/index.d.ts b/types/react-dom/v15/index.d.ts
index 8a22fd9bc2..653469b277 100644
--- a/types/react-dom/v15/index.d.ts
+++ b/types/react-dom/v15/index.d.ts
@@ -15,7 +15,7 @@ import {
     DOMAttributes, DOMElement
 } from 'react';
 
-export function findDOMNode<E extends Element>(instance: ReactInstance): E;
+export function findDOMNode<E extends Element>(instance: ReactInstance | null | undefined): E;
 export function findDOMNode(instance: ReactInstance): Element;
 
 export function render<P extends DOMAttributes<T>, T extends Element>(
diff --git a/types/react-dom/v15/react-dom-tests.ts b/types/react-dom/v15/react-dom-tests.ts
index 865d74e386..5f5b149594 100644
--- a/types/react-dom/v15/react-dom-tests.ts
+++ b/types/react-dom/v15/react-dom-tests.ts
@@ -25,6 +25,8 @@ describe('ReactDOM', () => {
         const rootElement = document.createElement('div');
         ReactDOM.render(React.createElement('div'), rootElement);
         ReactDOM.findDOMNode(rootElement);
+        ReactDOM.findDOMNode(null);
+        ReactDOM.findDOMNode(undefined);
     });
 });
 
diff --git a/types/react-native/index.d.ts b/types/react-native/index.d.ts
index 99865ac3be..0cee14dfd2 100644
--- a/types/react-native/index.d.ts
+++ b/types/react-native/index.d.ts
@@ -7662,6 +7662,9 @@ export interface PanResponderStatic {
 export interface Rationale {
     title: string;
     message: string;
+    buttonPositive: string;
+    buttonNegative?: string;
+    buttonNeutral?: string;
 }
 
 export type Permission =
diff --git a/types/three/index.d.ts b/types/three/index.d.ts
index 4e1f66e629..028ecc75dc 100644
--- a/types/three/index.d.ts
+++ b/types/three/index.d.ts
@@ -17,7 +17,6 @@
 //                 Daniel Hritzkiv <https://github.com/dhritzkiv>,
 //                 Apurva Ojas <https://github.com/apurvaojas>,
 //                 Tiger Oakes <https://github.com/NotWoods>,
-//                 Seth Kingsley <https://github.com/sethk>,
 //                 Ethan Kay <https://github.com/elk941>,
 //                 Methuselah96 <https://github.com/Methuselah96>
 //                 Dilip Ramirez <https://github.com/Dukuo>