Convert tool tip components to TypeScript

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 - Attach `noreferrer` also to links without `target="_blank"` ([#2008](https://github.com/elastic/eui/pull/2008))
 - Convert observer utility components to TypeScript ([#2009](https://github.com/elastic/eui/pull/2009))
+- Convert tool tip components to TypeScript ([#2013](https://github.com/elastic/eui/pull/2013))
 
 **Bug fixes**
 

src/components/badge/index.d.ts

@@ -1,5 +1,5 @@
 import { IconType } from '../icon';
-/// <reference path="../tool_tip/index.d.ts" />
+import { ToolTipPositions } from '../tool_tip/tool_tip';
 
 import {
   HTMLAttributes,

src/components/index.d.ts

@@ -28,7 +28,6 @@
 /// <reference path="./table/index.d.ts" />
 /// <reference path="./tabs/index.d.ts" />
 /// <reference path="./toast/index.d.ts" />
-/// <reference path="./tool_tip/index.d.ts" />
 
 declare module '@elastic/eui' {
   // @ts-ignore

src/components/tool_tip/icon_tip.tsx

@@ -0,0 +1,62 @@
+import React, { FunctionComponent } from 'react';
+
+import { Omit, PropsOf } from '../common';
+import { EuiIcon, IconSize, IconType } from '../icon';
+import { EuiToolTip, Props as EuiToolTipProps } from './tool_tip';
+
+export interface EuiIconTipProps {
+  /**
+   * The icon color.
+   */
+  color?: string;
+  /**
+   * The icon type.
+   */
+  type?: IconType;
+  /**
+   * The icon size.
+   */
+  size?: IconSize;
+  /**
+   * Explain what this icon means for screen readers.
+   */
+  'aria-label'?: string;
+
+  /**
+   * Pass certain props down to `EuiIcon`
+   */
+  // EuiIconTip's `type` is passed to EuiIcon, so we want to exclude `type` from
+  // iconProps; however, due to TS's bivariant function arguments `type` could be
+  // passed without any error/feedback so we explicitly set it to `never` type
+  iconProps?: Omit<PropsOf<EuiIcon>, 'type'> & { type?: never };
+}
+
+type Props = Omit<EuiToolTipProps, 'children' | 'delay' | 'position'> &
+  EuiIconTipProps & {
+    // This are copied from EuiToolTipProps, but made optional. Defaults
+    // are applied below.
+    delay?: EuiToolTipProps['delay'];
+    position?: EuiToolTipProps['position'];
+  };
+
+export const EuiIconTip: FunctionComponent<Props> = ({
+  type = 'questionInCircle',
+  'aria-label': ariaLabel = 'Info',
+  color,
+  size,
+  iconProps,
+  position = 'top',
+  delay = 'regular',
+  ...rest
+}) => (
+  <EuiToolTip position={position} delay={delay} {...rest}>
+    <EuiIcon
+      tabIndex={0}
+      type={type}
+      color={color}
+      size={size}
+      aria-label={ariaLabel}
+      {...iconProps}
+    />
+  </EuiToolTip>
+);