feat: re-add Portal + index.ts

Author: P0lip

src/Portal.tsx

@@ -0,0 +1,55 @@
+import * as React from 'react';
+import * as ReactDOM from 'react-dom';
+import { ThemeConsumer } from 'styled-components';
+
+export interface IPortalProps {
+  children: any;
+  className?: string;
+}
+
+export class Portal extends React.PureComponent<IPortalProps> {
+  private readonly el?: HTMLDivElement;
+  private readonly root = typeof document === 'object' ? document.body : null;
+
+  constructor(props: IPortalProps) {
+    super(props);
+
+    if (typeof document === 'undefined' || typeof document.createElement !== 'function') return;
+
+    this.el = document.createElement('div');
+
+    if (props.className !== undefined) {
+      this.el.className = props.className;
+    }
+  }
+
+  public componentDidMount() {
+    if (this.el !== undefined && this.root !== null) {
+      this.root.appendChild(this.el);
+    }
+  }
+
+  public componentWillUnmount() {
+    if (this.el !== undefined && this.root !== null) {
+      this.root.removeChild(this.el);
+    }
+  }
+
+  private renderChildren = () => {
+    const { children } = this.props;
+
+    if (typeof children === 'function') {
+      return children();
+    }
+
+    return React.Children.map(this.props.children, child => React.cloneElement(child));
+  };
+
+  public render() {
+    if (this.el === undefined) {
+      return null;
+    }
+
+    return ReactDOM.createPortal(<ThemeConsumer>{this.renderChildren}</ThemeConsumer>, this.el);
+  }
+}

src/index.ts

@@ -0,0 +1,23 @@
+/**
+ * NOTE: any components with meaningful external dependencies should NOT be exported here.
+ * Library users will need to `import { Select } from '@stoplight/ui-kit/select` them specifically.
+ */
+
+// export * from './BlockQuote';
+export * from './Break';
+export * from './Button';
+// export * from './ContextMenu';
+export * from './Flex';
+export * from './Heading';
+export * from './Icon';
+export * from './Image';
+// export * from './List';
+export * from './Link';
+// export * from './Popup';
+export * from './Portal';
+// export * from './Mark';
+// export * from './Menu';
+// export * from './Table';
+export * from './Text';
+// export * from './Toggle';
+export * from './theme/types';