Render should always return a html template (#4612)

src/components/entity/ha-entities-picker.ts

@@ -40,9 +40,9 @@ class HaEntitiesPickerLight extends LitElement {
   public pickedEntityLabel?: string;
   @property({ attribute: "pick-entity-label" }) public pickEntityLabel?: string;
 
-  protected render(): TemplateResult | void {
+  protected render(): TemplateResult {
     if (!this.hass) {
-      return;
+      return html``;
     }
 
     const currentEntities = this._currentEntities;

src/components/entity/ha-entity-picker.ts

@@ -145,7 +145,7 @@ class HaEntityPicker extends LitElement {
     }
   }
 
-  protected render(): TemplateResult | void {
+  protected render(): TemplateResult {
     const states = this._getStates(
       this._hass,
       this.includeDomains,

src/components/entity/ha-entity-toggle.ts

@@ -28,7 +28,7 @@ class HaEntityToggle extends LitElement {
   @property() public stateObj?: HassEntity;
   @property() private _isOn: boolean = false;
 
-  protected render(): TemplateResult | void {
+  protected render(): TemplateResult {
     if (!this.stateObj) {
       return html`
         <ha-switch disabled></ha-switch>

src/components/entity/ha-state-label-badge.ts

@@ -52,7 +52,7 @@ export class HaStateLabelBadge extends LitElement {
     this.clearInterval();
   }
 
-  protected render(): TemplateResult | void {
+  protected render(): TemplateResult {
     const state = this.state;
 
     if (!state) {

src/components/entity/state-badge.ts

@@ -28,7 +28,7 @@ export class StateBadge extends LitElement {
   @property({ type: Boolean }) public stateColor?: boolean;
   @query("ha-icon") private _icon!: HaIcon;
 
-  protected render(): TemplateResult | void {
+  protected render(): TemplateResult {
     const stateObj = this.stateObj;
 
     if (!stateObj) {