[EuiIcon] Add legacy/undocumented alert->warning alias (#6640)

* Add undocumented `alert`->`warning` alias

* [docs] Allow testing the `alert` alias in the playground
- without displaying it in the docs/grid

* changelog

src-docs/src/services/playground/iconValidator.js

@@ -4,6 +4,7 @@ import { mapOptions } from './mapOptions';
 import { PropTypes } from 'react-view';
 
 const iconOptions = mapOptions(iconTypes.concat(logoTypes));
+iconOptions.alert = 'warning'; // Legacy alias for Elastic Charts - primarily here for playground testing
 
 export const iconValidator = (prop = { custom: {} }, value) => {
   const newProp = {

src/components/icon/__snapshots__/icon.test.tsx.snap

@@ -610,6 +610,27 @@ exports[`EuiIcon props type aggregate is rendered 1`] = `
 </svg>
 `;
 
+exports[`EuiIcon props type alert is rendered 1`] = `
+<svg
+  aria-hidden="true"
+  class="euiIcon emotion-euiIcon-m-isLoaded"
+  data-icon-type="alert"
+  data-is-loaded="true"
+  height="16"
+  role="img"
+  viewBox="0 0 16 16"
+  width="16"
+  xmlns="http://www.w3.org/2000/svg"
+>
+  <path
+    d="M8.55 9.502l.35-3.507a.905.905 0 10-1.8 0l.35 3.507a.552.552 0 001.1 0zM9 12a1 1 0 11-2 0 1 1 0 012 0z"
+  />
+  <path
+    d="M8.864 1.496a1 1 0 00-1.728 0l-7 12A1 1 0 001 15h14a1 1 0 00.864-1.504l-7-12zM1 14L8 2l7 12H1z"
+  />
+</svg>
+`;
+
 exports[`EuiIcon props type analyzeEvent is rendered 1`] = `
 <svg
   aria-hidden="true"

src/components/icon/icon_map.ts

@@ -415,6 +415,7 @@ export const typeToPathMap = {
   visVisualBuilder: 'vis_visual_builder',
   visualizeApp: 'app_visualize',
   warning: 'warning',
+  alert: 'warning', // NOTE: This is an undocumented alias for `warning`, added for legacy compatability with Elastic Charts
   watchesApp: 'app_watches',
   wordWrap: 'wordWrap',
   wordWrapDisabled: 'wordWrapDisabled',

upcoming_changelogs/6640.md

@@ -0,0 +1,3 @@
+**Bug fixes**
+
+- Added a legacy `alert` alias for the `warning` `EuiIcon` type