fix setFocus() method on button

docs/getting-started/changelog.md

@@ -12,6 +12,7 @@ _During the beta period, these restrictions may be relaxed in the event of a mis
 - Fixed `aria-label` and `aria-labelledby` props in `sl-dialog` and `sl-drawer`
 - Fixed `tabindex` prop in `sl-menu`
 - Fixed a bug in `sl-select` where tags would always render as pills
+- Fixed a bug in `sl-button` where calling `setFocus()` would throw an error
 
 ## 2.0.0-beta.32
 

src/components/button/button.ts

@@ -1,4 +1,4 @@
-import { LitElement, html, internalProperty, property, unsafeCSS } from 'lit-element';
+import { LitElement, html, internalProperty, property, query, unsafeCSS } from 'lit-element';
 import { classMap } from 'lit-html/directives/class-map';
 import { ifDefined } from 'lit-html/directives/if-defined';
 import { event, EventEmitter, tag } from '../../internal/decorators';
@@ -26,7 +26,7 @@ import { hasSlot } from '../../internal/slot';
 export default class SlButton extends LitElement {
   static styles = unsafeCSS(styles);
 
-  button: HTMLButtonElement | HTMLLinkElement;
+  @query('.button') button: HTMLButtonElement | HTMLLinkElement;
 
   @internalProperty() private hasFocus = false;
   @internalProperty() private hasLabel = false;