@storybook/addon-knobs: add button() knob (#23302)

types/storybook__addon-knobs/index.d.ts

@@ -46,6 +46,8 @@ export function date(name: string, value?: Date): Date;
 
 export function array<T>(name: string, value: T[], separator?: string): T[];
 
+export function button(name: string, handler: () => any): void;
+
 export interface WrapStoryProps {
     context?: object;
     storyFn?: RenderFunction;

types/storybook__addon-knobs/storybook__addon-knobs-tests.tsx

@@ -11,6 +11,7 @@ import {
   select,
   date,
   array,
+  button,
   knob,
 } from '@storybook/addon-knobs';
 
@@ -58,6 +59,8 @@ stories.add('with all knobs', () => {
 
   const genericKnob: X = knob<X>('Some generic knob', { value: 'a', type: 'text' });
 
+  button('Some button', () => console.log('Button knob clicked'));
+
   const style = {
     ...customStyle,
     fontWeight: bold ? 800 as 800 : 400 as 400, // tslint:disable-line no-unnecessary-type-assertion