Explicitly annotate render's return type (#316)

rictic · justinfagnani · commit 27e76f92234f · 2018-11-29T15:47:02.000-08:00
diff --git a/src/lit-element.ts b/src/lit-element.ts
@@ -51,7 +51,6 @@ export class LitElement extends UpdatingElement {
    * Invoked on each update to perform rendering tasks. This method must return
    * a lit-html TemplateResult. Setting properties inside this method will *not*
    * trigger the element to update.
-   * @returns {TemplateResult} Must return a lit-html TemplateResult.
    */
-  protected render() {}
+  protected render(): TemplateResult|void {}
 }

Original file line number	Diff line number	Diff line change
`@@ -51,7 +51,6 @@ export class LitElement extends UpdatingElement {`
`51`	`51`	`* Invoked on each update to perform rendering tasks. This method must return`
`52`	`52`	`* a lit-html TemplateResult. Setting properties inside this method will not`
`53`	`53`	`* trigger the element to update.`
`54`		`- * @returns {TemplateResult} Must return a lit-html TemplateResult.`
`55`	`54`	`*/`
`56`		`- protected render() {}`
	`55`	`+ protected render(): TemplateResult\|void {}`
`57`	`56`	`}`