fix(theme): expose version property (#3978)

* fix: expose version property on theme

* fix: add unit test for theme version

tools/theme/src/Theme.ts

@@ -15,6 +15,7 @@ import {
     CSSResultGroup,
     supportsAdoptingStyleSheets,
 } from '@spectrum-web-components/base';
+import { version } from '@spectrum-web-components/base/src/version.js';
 
 declare global {
     interface Window {
@@ -95,6 +96,7 @@ export class Theme extends HTMLElement implements ThemeKindProvider {
     private static defaultFragments: Set<FragmentName> = new Set(['spectrum']);
     private static templateElement?: HTMLTemplateElement;
     private static instances: Set<Theme> = new Set();
+    static VERSION = version;
 
     static get observedAttributes(): string[] {
         return ['color', 'scale', 'theme', 'lang', 'dir'];

tools/theme/test/theme.test.ts

@@ -0,0 +1,23 @@
+/*
+Copyright 2020 Adobe. All rights reserved.
+This file is licensed to you under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License. You may obtain a copy
+of the License at http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software distributed under
+the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
+OF ANY KIND, either express or implied. See the License for the specific language
+governing permissions and limitations under the License.
+*/
+import { Theme } from '@spectrum-web-components/theme';
+import { expect } from '@open-wc/testing';
+import { version } from '@spectrum-web-components/base/src/version.js';
+
+class DirElement extends Theme {}
+
+customElements.define('dir-element', DirElement);
+
+describe('Theme', () => {
+    it('has a static VERSION property', () => {
+        expect(DirElement.VERSION).to.equal(version);
+    });
+});