✨ introducing fitContainer prop for button

components/button/__tests__/__snapshots__/demo.test.js.snap

@@ -252,6 +252,43 @@ exports[`renders ./components/button/demo/disabled.md correctly 1`] = `
 </div>
 `;
 
+exports[`renders ./components/button/demo/fitContainer.md correctly 1`] = `
+<div>
+  <button
+    class="ant-btn ant-btn-primary ant-btn-fit"
+    type="button"
+  >
+    <span>
+      Primary
+    </span>
+  </button>
+  <button
+    class="ant-btn ant-btn-fit"
+    type="button"
+  >
+    <span>
+      Default
+    </span>
+  </button>
+  <button
+    class="ant-btn ant-btn-dashed ant-btn-fit"
+    type="button"
+  >
+    <span>
+      Dashed
+    </span>
+  </button>
+  <button
+    class="ant-btn ant-btn-danger ant-btn-fit"
+    type="button"
+  >
+    <span>
+      danger
+    </span>
+  </button>
+</div>
+`;
+
 exports[`renders ./components/button/demo/ghost.md correctly 1`] = `
 <div
   style="background:rgb(190, 200, 200);padding:26px 16px 16px"
@@ -460,7 +497,7 @@ exports[`renders ./components/button/demo/multiple.md correctly 1`] = `
     type="button"
   >
     <span>
-      Actions 
+      Actions
     </span>
     <i
       class="anticon anticon-down"

components/button/button.tsx

@@ -47,6 +47,7 @@ export interface BaseButtonProps {
   prefixCls?: string;
   className?: string;
   ghost?: boolean;
+  fitContainer?: boolean;
 }
 
 export type AnchorButtonProps = {
@@ -70,6 +71,7 @@ export default class Button extends React.Component<ButtonProps, any> {
     prefixCls: 'ant-btn',
     loading: false,
     ghost: false,
+    fitContainer: false,
   };
 
   static propTypes = {
@@ -163,7 +165,7 @@ export default class Button extends React.Component<ButtonProps, any> {
 
   render() {
     const {
-      type, shape, size, className, children, icon, prefixCls, ghost, loading: _loadingProp, ...rest
+      type, shape, size, className, children, icon, prefixCls, ghost, loading: _loadingProp, fitContainer, ...rest
     } = this.props;
 
     const { loading, clicked, hasTwoCNChar } = this.state;
@@ -190,6 +192,7 @@ export default class Button extends React.Component<ButtonProps, any> {
       [`${prefixCls}-clicked`]: clicked,
       [`${prefixCls}-background-ghost`]: ghost,
       [`${prefixCls}-two-chinese-chars`]: hasTwoCNChar,
+      [`${prefixCls}-fit`]: fitContainer,
     });
 
     const iconType = loading ? 'loading' : icon;

components/button/demo/fitContainer.md

@@ -0,0 +1,27 @@
+---
+order: 8
+title:
+  zh-CN: fitContainer 按钮
+  en-US: fitContainer Button
+---
+
+## zh-CN
+
+`fitContainer`属性将使按钮适合其父宽度。
+
+## en-US
+
+`fitContainer` property will make the button fit to its parent width.
+
+````jsx
+import { Button } from 'antd';
+
+ReactDOM.render(
+  <div>
+    <Button type="primary" fitContainer>Primary</Button>
+    <Button fitContainer>Default</Button>
+    <Button type="dashed" fitContainer>Dashed</Button>
+    <Button type="danger" fitContainer>danger</Button>
+  </div>,
+  mountNode);
+````

components/button/style/index.less

@@ -171,6 +171,10 @@
     letter-spacing: .34em;
     margin-right: -.34em;
   }
+
+  &-fit {
+    width: 100%;
+  }
 }
 
 @keyframes buttonEffect {