Prefer nothing over empty templates (#15633)

.eslintrc.json

@@ -119,7 +119,6 @@
     "lit/no-template-map": "off",
     "lit/no-native-attributes": "warn",
     "lit/no-this-assign-in-render": "warn",
-    "lit/prefer-nothing": "warn",
     "lit-a11y/click-events-have-key-events": ["off"],
     "lit-a11y/no-autofocus": "off",
     "lit-a11y/alt-text": "warn",

cast/src/receiver/layout/hc-demo.ts

@@ -1,4 +1,4 @@
-import { html, TemplateResult } from "lit";
+import { html, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { mockHistory } from "../../../../demo/src/stubs/history";
 import { LovelaceConfig } from "../../../../src/data/lovelace";
@@ -18,9 +18,9 @@ class HcDemo extends HassElement {
 
   @state() private _lovelaceConfig?: LovelaceConfig;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._lovelaceConfig) {
-      return html``;
+      return nothing;
     }
     return html`
       <hc-lovelace

demo/src/custom-cards/cast-demo-row.ts

@@ -1,5 +1,5 @@
 import { mdiTelevision } from "@mdi/js";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, state } from "lit/decorators";
 import { CastManager } from "../../../src/cast/cast_manager";
 import { castSendShowDemo } from "../../../src/cast/receiver_messages";
@@ -20,12 +20,12 @@ class CastDemoRow extends LitElement implements LovelaceRow {
     // No config possible.
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (
       !this._castManager ||
       this._castManager.castState === "NO_DEVICES_AVAILABLE"
     ) {
-      return html``;
+      return nothing;
     }
     return html`
       <ha-svg-icon .path=${mdiTelevision}></ha-svg-icon>

demo/src/custom-cards/ha-demo-card.ts

@@ -1,5 +1,5 @@
 import "@material/mwc-button";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { until } from "lit/directives/until";
 import "../../../src/components/ha-card";
@@ -30,9 +30,9 @@ export class HADemoCard extends LitElement implements LovelaceCard {
 
   public setConfig(_config: LovelaceCardConfig) {}
 
-  protected render(): TemplateResult {
+  protected render() {
     if (this._hidden) {
-      return html``;
+      return nothing;
     }
     return html`
       <ha-card>

gallery/src/components/page-description.ts

@@ -1,4 +1,4 @@
-import { html, css } from "lit";
+import { css, html, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import { until } from "lit/directives/until";
 import { HaMarkdown } from "../../../src/components/ha-markdown";
@@ -10,7 +10,7 @@ class PageDescription extends HaMarkdown {
 
   render() {
     if (!PAGES[this.page].description) {
-      return html``;
+      return nothing;
     }
 
     return html`

gallery/src/pages/automation/describe-action.ts

@@ -1,5 +1,5 @@
 import { dump } from "js-yaml";
-import { html, css, LitElement, TemplateResult } from "lit";
+import { css, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/ha-yaml-editor";
@@ -127,9 +127,9 @@ export class DemoAutomationDescribeAction extends LitElement {
 
   @state() _action = initialAction;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass) {
-      return html``;
+      return nothing;
     }
     return html`
       <ha-card header="Actions">

gallery/src/pages/automation/describe-condition.ts

@@ -1,5 +1,5 @@
 import { dump } from "js-yaml";
-import { css, html, LitElement, TemplateResult } from "lit";
+import { css, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/ha-yaml-editor";
@@ -53,9 +53,9 @@ export class DemoAutomationDescribeCondition extends LitElement {
 
   @state() _condition = initialCondition;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass) {
-      return html``;
+      return nothing;
     }
 
     return html`

gallery/src/pages/automation/describe-trigger.ts

@@ -1,5 +1,5 @@
 import { dump } from "js-yaml";
-import { css, html, LitElement, TemplateResult } from "lit";
+import { css, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/ha-yaml-editor";
@@ -64,9 +64,9 @@ export class DemoAutomationDescribeTrigger extends LitElement {
 
   @state() _trigger = initialTrigger;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass) {
-      return html``;
+      return nothing;
     }
 
     return html`

gallery/src/pages/automation/trace-timeline.ts

@@ -1,5 +1,6 @@
 /* eslint-disable lit/no-template-arrow */
-import { html, css, LitElement, TemplateResult } from "lit";
+
+import { css, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/trace/hat-script-graph";
@@ -29,9 +30,9 @@ const traces: DemoTrace[] = [
 export class DemoAutomationTraceTimeline extends LitElement {
   @property({ attribute: false }) hass?: HomeAssistant;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass) {
-      return html``;
+      return nothing;
     }
     return html`
       ${traces.map(

gallery/src/pages/automation/trace.ts

@@ -1,14 +1,15 @@
 /* eslint-disable lit/no-template-arrow */
-import { html, css, LitElement, TemplateResult } from "lit";
+
+import { css, html, LitElement, nothing } from "lit";
+import { customElement, property, state } from "lit/decorators";
 import "../../../../src/components/ha-card";
 import "../../../../src/components/trace/hat-script-graph";
 import "../../../../src/components/trace/hat-trace-timeline";
-import { customElement, property, state } from "lit/decorators";
 import { provideHass } from "../../../../src/fake_data/provide_hass";
 import { HomeAssistant } from "../../../../src/types";
-import { DemoTrace } from "../../data/traces/types";
 import { basicTrace } from "../../data/traces/basic_trace";
 import { motionLightTrace } from "../../data/traces/motion-light-trace";
+import { DemoTrace } from "../../data/traces/types";
 
 const traces: DemoTrace[] = [basicTrace, motionLightTrace];
 
@@ -18,9 +19,9 @@ export class DemoAutomationTrace extends LitElement {
 
   @state() private _selected = {};
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass) {
-      return html``;
+      return nothing;
     }
     return html`
       ${traces.map(

gallery/src/pages/misc/entity-state.ts

@@ -2,7 +2,7 @@ import {
   HassEntity,
   HassEntityAttributeBase,
 } from "home-assistant-js-websocket";
-import { css, html, LitElement, TemplateResult } from "lit";
+import { css, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import memoizeOne from "memoize-one";
 import { computeDomain } from "../../../../src/common/entity/compute_domain";
@@ -387,9 +387,9 @@ export class DemoEntityState extends LitElement {
     hass.updateTranslations("config", "en");
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass) {
-      return html``;
+      return nothing;
     }
 
     return html`

gallery/src/pages/misc/integration-card.ts

@@ -1,22 +1,22 @@
-import { html, css, LitElement, TemplateResult } from "lit";
+import { css, html, LitElement, nothing } from "lit";
 import "../../../../src/components/ha-formfield";
 import "../../../../src/components/ha-switch";
 
-import { classMap } from "lit/directives/class-map";
 import { customElement, property, state } from "lit/decorators";
+import { classMap } from "lit/directives/class-map";
 import { IntegrationManifest } from "../../../../src/data/integration";
 
+import { DeviceRegistryEntry } from "../../../../src/data/device_registry";
+import { EntityRegistryEntry } from "../../../../src/data/entity_registry";
 import { provideHass } from "../../../../src/fake_data/provide_hass";
-import { HomeAssistant } from "../../../../src/types";
-import "../../../../src/panels/config/integrations/ha-integration-card";
-import "../../../../src/panels/config/integrations/ha-ignored-config-entry-card";
 import "../../../../src/panels/config/integrations/ha-config-flow-card";
 import type {
   ConfigEntryExtended,
   DataEntryFlowProgressExtended,
 } from "../../../../src/panels/config/integrations/ha-config-integrations";
-import { DeviceRegistryEntry } from "../../../../src/data/device_registry";
+import "../../../../src/panels/config/integrations/ha-ignored-config-entry-card";
-import { EntityRegistryEntry } from "../../../../src/data/entity_registry";
+import "../../../../src/panels/config/integrations/ha-integration-card";
+import { HomeAssistant } from "../../../../src/types";
 
 const createConfigEntry = (
   title: string,
@@ -231,9 +231,9 @@ export class DemoIntegrationCard extends LitElement {
 
   @state() isCloud = false;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass) {
-      return html``;
+      return nothing;
     }
     return html`
       <div class="container">

hassio/src/addon-store/hassio-addon-store.ts

@@ -6,6 +6,7 @@ import {
   CSSResultGroup,
   html,
   LitElement,
+  nothing,
   PropertyValues,
   TemplateResult,
 } from "lit";
@@ -73,8 +74,8 @@ export class HassioAddonStore extends LitElement {
     }
   }
 
-  protected render(): TemplateResult {
+  protected render() {
-    let repos: TemplateResult[] = [];
+    let repos: (TemplateResult | typeof nothing)[] = [];
 
     if (this.supervisor.store.repositories) {
       repos = this.addonRepositories(
@@ -173,7 +174,7 @@ export class HassioAddonStore extends LitElement {
                 .supervisor=${this.supervisor}
               ></hassio-addon-repository>
             `
-          : html``;
+          : nothing;
       })
   );
 

hassio/src/addon-view/config/hassio-addon-network.ts

@@ -4,7 +4,7 @@ import {
   html,
   LitElement,
   PropertyValues,
-  TemplateResult,
+  nothing,
 } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import memoizeOne from "memoize-one";
@@ -47,9 +47,9 @@ class HassioAddonNetwork extends LitElement {
     this._setNetworkConfig();
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._config) {
-      return html``;
+      return nothing;
     }
 
     const hasHiddenOptions = Object.keys(this._config).find(

hassio/src/backups/hassio-backups.ts

@@ -8,7 +8,7 @@ import {
   html,
   LitElement,
   PropertyValues,
-  TemplateResult,
+  nothing,
 } from "lit";
 import { customElement, property, query, state } from "lit/decorators";
 import { classMap } from "lit/directives/class-map";
@@ -160,9 +160,9 @@ export class HassioBackups extends LitElement {
     }))
   );
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.supervisor) {
-      return html``;
+      return nothing;
     }
     return html`
       <hass-tabs-subpage-data-table

hassio/src/components/supervisor-backup-content.ts

@@ -1,6 +1,13 @@
 import { mdiFolder, mdiHomeAssistant, mdiPuzzle } from "@mdi/js";
 import { PaperInputElement } from "@polymer/paper-input/paper-input";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import {
+  css,
+  CSSResultGroup,
+  html,
+  LitElement,
+  TemplateResult,
+  nothing,
+} from "lit";
 import { customElement, property, query } from "lit/decorators";
 import { atLeastVersion } from "../../../src/common/config/version";
 import { formatDate } from "../../../src/common/datetime/format_date";
@@ -11,9 +18,9 @@ import "../../../src/components/ha-formfield";
 import "../../../src/components/ha-radio";
 import type { HaRadio } from "../../../src/components/ha-radio";
 import {
+  HassioBackupDetail,
   HassioFullBackupCreateParams,
   HassioPartialBackupCreateParams,
-  HassioBackupDetail,
 } from "../../../src/data/hassio/backup";
 import { Supervisor } from "../../../src/data/supervisor/supervisor";
 import { PolymerChangedEvent } from "../../../src/polymer-types";
@@ -115,9 +122,9 @@ export class SupervisorBackupContent extends LitElement {
     this.supervisor?.localize(`backup.${key}`) ||
     this.localize!(`ui.panel.page-onboarding.restore.${key}`);
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.onboarding && !this.supervisor) {
-      return html``;
+      return nothing;
     }
     const foldersSection =
       this.backupType === "partial" ? this._getSection("folders") : undefined;

hassio/src/dashboard/hassio-update.ts

@@ -1,6 +1,6 @@
 import "@material/mwc-button";
 import { mdiHomeAssistant } from "@mdi/js";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import memoizeOne from "memoize-one";
 import "../../../src/components/buttons/ha-progress-button";
@@ -33,14 +33,14 @@ export class HassioUpdate extends LitElement {
       ).length
   );
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.supervisor) {
-      return html``;
+      return nothing;
     }
 
     const updatesAvailable = this._pendingUpdates(this.supervisor);
     if (!updatesAvailable) {
-      return html``;
+      return nothing;
     }
 
     return html`
@@ -80,9 +80,9 @@ export class HassioUpdate extends LitElement {
     name: string,
     key: string,
     object: HassioHomeAssistantInfo | HassioSupervisorInfo | HassioHassOSInfo
-  ): TemplateResult {
+  ) {
     if (!object.update_available) {
-      return html``;
+      return nothing;
     }
     return html`
       <ha-card outlined>

hassio/src/dialogs/backup/dialog-hassio-backup-upload.ts

@@ -1,5 +1,5 @@
 import { mdiClose } from "@mdi/js";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { fireEvent } from "../../../../src/common/dom/fire_event";
 import "../../../../src/components/ha-header-bar";
@@ -36,9 +36,9 @@ export class DialogHassioBackupUpload
     fireEvent(this, "dialog-closed", { dialog: this.localName });
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._dialogParams) {
-      return html``;
+      return nothing;
     }
 
     return html`

hassio/src/dialogs/backup/dialog-hassio-backup.ts

@@ -1,9 +1,11 @@
 import { ActionDetail } from "@material/mwc-list";
 import "@material/mwc-list/mwc-list-item";
 import { mdiClose, mdiDotsVertical } from "@mdi/js";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property, query, state } from "lit/decorators";
+import { atLeastVersion } from "../../../../src/common/config/version";
 import { fireEvent } from "../../../../src/common/dom/fire_event";
+import { stopPropagation } from "../../../../src/common/dom/stop_propagation";
 import { slugify } from "../../../../src/common/string/slugify";
 import "../../../../src/components/buttons/ha-progress-button";
 import "../../../../src/components/ha-alert";
@@ -11,11 +13,11 @@ import "../../../../src/components/ha-button-menu";
 import "../../../../src/components/ha-header-bar";
 import "../../../../src/components/ha-icon-button";
 import { getSignedPath } from "../../../../src/data/auth";
-import { extractApiErrorMessage } from "../../../../src/data/hassio/common";
 import {
   fetchHassioBackupInfo,
   HassioBackupDetail,
 } from "../../../../src/data/hassio/backup";
+import { extractApiErrorMessage } from "../../../../src/data/hassio/common";
 import {
   showAlertDialog,
   showConfirmationDialog,
@@ -27,8 +29,6 @@ import { fileDownload } from "../../../../src/util/file_download";
 import "../../components/supervisor-backup-content";
 import type { SupervisorBackupContent } from "../../components/supervisor-backup-content";
 import { HassioBackupDialogParams } from "./show-dialog-hassio-backup";
-import { atLeastVersion } from "../../../../src/common/config/version";
-import { stopPropagation } from "../../../../src/common/dom/stop_propagation";
 
 @customElement("dialog-hassio-backup")
 class HassioBackupDialog
@@ -62,9 +62,9 @@ class HassioBackupDialog
     fireEvent(this, "dialog-closed", { dialog: this.localName });
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._dialogParams || !this._backup) {
-      return html``;
+      return nothing;
     }
     return html`
       <ha-dialog

hassio/src/dialogs/backup/dialog-hassio-create-backup.ts

@@ -1,15 +1,15 @@
 import "@material/mwc-button";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property, query, state } from "lit/decorators";
 import { fireEvent } from "../../../../src/common/dom/fire_event";
-import "../../../../src/components/ha-alert";
 import "../../../../src/components/buttons/ha-progress-button";
+import "../../../../src/components/ha-alert";
 import { createCloseHeading } from "../../../../src/components/ha-dialog";
-import { extractApiErrorMessage } from "../../../../src/data/hassio/common";
 import {
   createHassioFullBackup,
   createHassioPartialBackup,
 } from "../../../../src/data/hassio/backup";
+import { extractApiErrorMessage } from "../../../../src/data/hassio/common";
 import { showAlertDialog } from "../../../../src/dialogs/generic/show-dialog-box";
 import { haStyle, haStyleDialog } from "../../../../src/resources/styles";
 import { HomeAssistant } from "../../../../src/types";
@@ -42,9 +42,9 @@ class HassioCreateBackupDialog extends LitElement {
     fireEvent(this, "dialog-closed", { dialog: this.localName });
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._dialogParams) {
-      return html``;
+      return nothing;
     }
     return html`
       <ha-dialog

hassio/src/dialogs/datadisk/dialog-hassio-datadisk.ts

@@ -1,5 +1,5 @@
 import "@material/mwc-list/mwc-list-item";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import memoizeOne from "memoize-one";
 import { fireEvent } from "../../../../src/common/dom/fire_event";
@@ -55,9 +55,9 @@ class HassioDatadiskDialog extends LitElement {
     fireEvent(this, "dialog-closed", { dialog: this.localName });
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.dialogParams) {
-      return html``;
+      return nothing;
     }
     return html`
       <ha-dialog

hassio/src/dialogs/hardware/dialog-hassio-hardware.ts

@@ -1,13 +1,13 @@
 import { mdiClose } from "@mdi/js";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import memoizeOne from "memoize-one";
 import { fireEvent } from "../../../../src/common/dom/fire_event";
-import "../../../../src/components/search-input";
 import { stringCompare } from "../../../../src/common/string/compare";
 import "../../../../src/components/ha-dialog";
 import "../../../../src/components/ha-expansion-panel";
 import "../../../../src/components/ha-icon-button";
+import "../../../../src/components/search-input";
 import { HassioHardwareInfo } from "../../../../src/data/hassio/hardware";
 import { dump } from "../../../../src/resources/js-yaml-dump";
 import { haStyle, haStyleDialog } from "../../../../src/resources/styles";
@@ -53,9 +53,9 @@ class HassioHardwareDialog extends LitElement {
     fireEvent(this, "dialog-closed", { dialog: this.localName });
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._dialogParams) {
-      return html``;
+      return nothing;
     }
 
     const devices = _filterDevices(

hassio/src/dialogs/markdown/dialog-hassio-markdown.ts

@@ -1,4 +1,4 @@
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { createCloseHeading } from "../../../../src/components/ha-dialog";
 import "../../../../src/components/ha-markdown";
@@ -27,9 +27,9 @@ class HassioMarkdownDialog extends LitElement {
     this._opened = false;
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._opened) {
-      return html``;
+      return nothing;
     }
     return html`
       <ha-dialog

hassio/src/dialogs/network/dialog-hassio-network.ts

@@ -5,7 +5,7 @@ import "@material/mwc-tab";
 import "@material/mwc-tab-bar";
 import { mdiClose } from "@mdi/js";
 import { PaperInputElement } from "@polymer/paper-input/paper-input";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { cache } from "lit/directives/cache";
 import { fireEvent } from "../../../../src/common/dom/fire_event";
@@ -83,9 +83,9 @@ export class DialogHassioNetwork
     fireEvent(this, "dialog-closed", { dialog: this.localName });
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._params || !this._interface) {
-      return html``;
+      return nothing;
     }
 
     return html`

hassio/src/dialogs/repositories/dialog-hassio-repositories.ts

@@ -1,11 +1,11 @@
-import "@polymer/paper-tooltip/paper-tooltip";
 import "@material/mwc-button/mwc-button";
 import { mdiDelete, mdiDeleteOff } from "@mdi/js";
 import "@polymer/paper-input/paper-input";
 import type { PaperInputElement } from "@polymer/paper-input/paper-input";
 import "@polymer/paper-item/paper-item";
 import "@polymer/paper-item/paper-item-body";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import "@polymer/paper-tooltip/paper-tooltip";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property, query, state } from "lit/decorators";
 import memoizeOne from "memoize-one";
 import { fireEvent } from "../../../../src/common/dom/fire_event";
@@ -19,14 +19,14 @@ import {
   HassioAddonRepository,
 } from "../../../../src/data/hassio/addon";
 import { extractApiErrorMessage } from "../../../../src/data/hassio/common";
-import { haStyle, haStyleDialog } from "../../../../src/resources/styles";
-import type { HomeAssistant } from "../../../../src/types";
-import { HassioRepositoryDialogParams } from "./show-dialog-repositories";
 import {
   addStoreRepository,
   fetchStoreRepositories,
   removeStoreRepository,
 } from "../../../../src/data/supervisor/store";
+import { haStyle, haStyleDialog } from "../../../../src/resources/styles";
+import type { HomeAssistant } from "../../../../src/types";
+import { HassioRepositoryDialogParams } from "./show-dialog-repositories";
 
 @customElement("dialog-hassio-repositories")
 class HassioRepositoriesDialog extends LitElement {
@@ -82,9 +82,9 @@ class HassioRepositoriesDialog extends LitElement {
         .map((repo) => repo.slug)
   );
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._dialogParams?.supervisor || this._repositories === undefined) {
-      return html``;
+      return nothing;
     }
     const repositories = this._filteredRepositories(this._repositories);
     const usedRepositories = this._filteredUsedRepositories(

hassio/src/hassio-my-redirect.ts

@@ -1,5 +1,5 @@
 import { sanitizeUrl } from "@braintree/sanitize-url";
-import { html, LitElement, TemplateResult } from "lit";
+import { html, LitElement, TemplateResult, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { navigate } from "../../src/common/navigate";
 import {
@@ -101,13 +101,13 @@ class HassioMyRedirect extends LitElement {
     navigate(url, { replace: true });
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (this._error) {
       return html`<hass-error-screen
         .error=${this._error}
       ></hass-error-screen>`;
     }
-    return html``;
+    return nothing;
   }
 
   private _createRedirectUrl(redirect: Redirect): string {

hassio/src/update-available/update-available-card.ts

@@ -5,7 +5,7 @@ import {
   html,
   LitElement,
   PropertyValues,
-  TemplateResult,
+  nothing,
 } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import memoizeOne from "memoize-one";
@@ -116,12 +116,12 @@ class UpdateAvailableCard extends LitElement {
       storeAddons.find((addon) => addon.slug === slug)
   );
 
-  protected render(): TemplateResult {
+  protected render() {
     if (
       !this._updateType ||
       (this._updateType === "addon" && !this._addonInfo)
     ) {
-      return html``;
+      return nothing;
     }
 
     const changelog = changelogUrl(this._updateType, this._version_latest);

src/auth/ha-auth-flow.ts

@@ -5,8 +5,8 @@ import {
   CSSResultGroup,
   html,
   LitElement,
+  nothing,
   PropertyValues,
-  TemplateResult,
 } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import "../components/ha-alert";
@@ -134,11 +134,11 @@ export class HaAuthFlow extends litLocalizeLiteMixin(LitElement) {
     }, 500);
   }
 
-  private _renderForm(): TemplateResult {
+  private _renderForm() {
     switch (this._state) {
       case "step":
         if (this._step == null) {
-          return html``;
+          return nothing;
         }
         return html`
           ${this._renderStep(this._step)}
@@ -176,11 +176,11 @@ export class HaAuthFlow extends litLocalizeLiteMixin(LitElement) {
           </ha-alert>
         `;
       default:
-        return html``;
+        return nothing;
     }
   }
 
-  private _renderStep(step: DataEntryFlowStep): TemplateResult {
+  private _renderStep(step: DataEntryFlowStep) {
     switch (step.type) {
       case "abort":
         return html`
@@ -202,7 +202,7 @@ export class HaAuthFlow extends litLocalizeLiteMixin(LitElement) {
                   .content=${this._computeStepDescription(step)}
                 ></ha-markdown>
               `
-            : html``}
+            : nothing}
           <ha-form
             .data=${this._stepData}
             .schema=${autocompleteLoginFields(step.data_schema)}
@@ -228,7 +228,7 @@ export class HaAuthFlow extends litLocalizeLiteMixin(LitElement) {
             : ""}
         `;
       default:
-        return html``;
+        return nothing;
     }
   }
 

src/components/chart/state-history-charts.ts

@@ -4,11 +4,12 @@ import {
   CSSResultGroup,
   html,
   LitElement,
+  nothing,
   PropertyValues,
-  TemplateResult,
 } from "lit";
-import { customElement, property, state, eventOptions } from "lit/decorators";
+import { customElement, eventOptions, property, state } from "lit/decorators";
 import { isComponentLoaded } from "../../common/config/is_component_loaded";
+import { restoreScroll } from "../../common/decorators/restore-scroll";
 import {
   HistoryResult,
   LineChartUnit,
@@ -17,7 +18,6 @@ import {
 import type { HomeAssistant } from "../../types";
 import "./state-history-chart-line";
 import "./state-history-chart-timeline";
-import { restoreScroll } from "../../common/decorators/restore-scroll";
 
 const CANVAS_TIMELINE_ROWS_CHUNK = 10; // Split up the canvases to avoid hitting the render limit
 
@@ -71,7 +71,7 @@ export class StateHistoryCharts extends LitElement {
   // @ts-ignore
   @restoreScroll(".container") private _savedScrollPos?: number;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!isComponentLoaded(this.hass, "history")) {
       return html`<div class="info">
         ${this.hass.localize("ui.components.history_charts.history_disabled")}
@@ -130,9 +130,9 @@ export class StateHistoryCharts extends LitElement {
   private _renderHistoryItem = (
     item: TimelineEntity[] | LineChartUnit,
     index: number
-  ): TemplateResult => {
+  ) => {
     if (!item || index === undefined) {
-      return html``;
+      return nothing;
     }
     if (!Array.isArray(item)) {
       return html`<div class="entry-container">

src/components/data-table/ha-data-table.ts

@@ -6,6 +6,7 @@ import {
   CSSResultGroup,
   html,
   LitElement,
+  nothing,
   PropertyValues,
   TemplateResult,
 } from "lit";
@@ -73,7 +74,7 @@ export interface DataTableColumnData<T = any> extends DataTableSortColumnData {
   title: TemplateResult | string;
   label?: TemplateResult | string;
   type?: "numeric" | "icon" | "icon-button" | "overflow-menu";
-  template?: (data: any, row: T) => TemplateResult | string;
+  template?: (data: any, row: T) => TemplateResult | string | typeof nothing;
   width?: string;
   maxWidth?: string;
   grows?: boolean;
@@ -352,13 +353,10 @@ export class HaDataTable extends LitElement {
     `;
   }
 
-  private _renderRow = (
+  private _renderRow = (row: DataTableRowData, index: number) => {
-    row: DataTableRowData,
-    index: number
-  ): TemplateResult => {
     // not sure how this happens...
     if (!row) {
-      return html``;
+      return nothing;
     }
     if (row.append) {
       return html` <div class="mdc-data-table__row">${row.content}</div> `;

src/components/device/ha-area-devices-picker.ts

@@ -1,7 +1,7 @@
 import "@material/mwc-button/mwc-button";
-import { UnsubscribeFunc } from "home-assistant-js-websocket";
-import { html, LitElement, PropertyValues, TemplateResult } from "lit";
 import { ComboBoxLitRenderer } from "@vaadin/combo-box/lit";
+import { UnsubscribeFunc } from "home-assistant-js-websocket";
+import { html, LitElement, PropertyValues, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import memoizeOne from "memoize-one";
 import { fireEvent } from "../../common/dom/fire_event";
@@ -230,9 +230,9 @@ export class HaAreaDevicesPicker extends SubscribeMixin(LitElement) {
     }
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._devices || !this._areas || !this._entities) {
-      return html``;
+      return nothing;
     }
     const areas = this._getAreasWithDevices(
       this._devices,

src/components/device/ha-device-automation-picker.ts

@@ -1,5 +1,5 @@
 import "@material/mwc-list/mwc-list-item";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { property, state } from "lit/decorators";
 import { fireEvent } from "../../common/dom/fire_event";
 import {
@@ -85,9 +85,9 @@ export abstract class HaDeviceAutomationPicker<
     return `${this._automations[idx].device_id}_${idx}`;
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (this._renderEmpty) {
-      return html``;
+      return nothing;
     }
     const value = this._value;
     return html`

src/components/device/ha-devices-picker.ts

@@ -1,4 +1,4 @@
-import { css, html, LitElement, TemplateResult } from "lit";
+import { css, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import { fireEvent } from "../../common/dom/fire_event";
 import { PolymerChangedEvent } from "../../polymer-types";
@@ -49,9 +49,9 @@ class HaDevicesPicker extends LitElement {
 
   @property() public entityFilter?: HaDevicePickerEntityFilterFunc;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass) {
-      return html``;
+      return nothing;
     }
 
     const currentDevices = this._currentDevices;

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

@@ -1,5 +1,5 @@
 import type { HassEntity } from "home-assistant-js-websocket";
-import { css, html, LitElement, TemplateResult } from "lit";
+import { css, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import memoizeOne from "memoize-one";
 import { fireEvent } from "../../common/dom/fire_event";
@@ -76,9 +76,9 @@ class HaEntitiesPickerLight extends LitElement {
 
   @property() public entityFilter?: HaEntityPickerEntityFilterFunc;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass) {
-      return html``;
+      return nothing;
     }
 
     const currentEntities = this._currentEntities;

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

@@ -1,5 +1,5 @@
 import { HassEntity } from "home-assistant-js-websocket";
-import { html, LitElement, PropertyValues, TemplateResult } from "lit";
+import { html, LitElement, PropertyValues, nothing } from "lit";
 import { customElement, property, query } from "lit/decorators";
 import { formatAttributeName } from "../../data/entity_attributes";
 import { PolymerChangedEvent } from "../../polymer-types";
@@ -60,9 +60,9 @@ class HaEntityAttributePicker extends LitElement {
     }
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass) {
-      return html``;
+      return nothing;
     }
 
     return html`

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

@@ -1,14 +1,14 @@
 import { HassEntity } from "home-assistant-js-websocket";
-import { html, LitElement, PropertyValues, TemplateResult } from "lit";
+import { html, LitElement, PropertyValues, nothing } from "lit";
 import { customElement, property, query } from "lit/decorators";
+import { fireEvent } from "../../common/dom/fire_event";
 import { computeStateDisplay } from "../../common/entity/compute_state_display";
-import { PolymerChangedEvent } from "../../polymer-types";
 import { getStates } from "../../common/entity/get_states";
+import { formatAttributeValue } from "../../data/entity_attributes";
+import { PolymerChangedEvent } from "../../polymer-types";
 import { HomeAssistant } from "../../types";
 import "../ha-combo-box";
 import type { HaComboBox } from "../ha-combo-box";
-import { formatAttributeValue } from "../../data/entity_attributes";
-import { fireEvent } from "../../common/dom/fire_event";
 
 export type HaEntityPickerEntityFilterFunc = (entityId: HassEntity) => boolean;
 
@@ -64,9 +64,9 @@ class HaEntityStatePicker extends LitElement {
     }
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass) {
-      return html``;
+      return nothing;
     }
 
     return html`

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

@@ -1,4 +1,4 @@
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import { fireEvent } from "../../common/dom/fire_event";
 import type { PolymerChangedEvent } from "../../polymer-types";
@@ -56,9 +56,9 @@ class HaStatisticsPicker extends LitElement {
   })
   public ignoreRestrictionsOnFirstStatistic = false;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass) {
-      return html``;
+      return nothing;
     }
 
     const ignoreRestriction =

src/components/entity/state-badge.ts

@@ -6,7 +6,7 @@ import {
   html,
   LitElement,
   PropertyValues,
-  TemplateResult,
+  nothing,
 } from "lit";
 import { property, state } from "lit/decorators";
 import { ifDefined } from "lit/directives/if-defined";
@@ -45,7 +45,7 @@ export class StateBadge extends LitElement {
     return this.stateColor || (domain === "light" && this.stateColor !== false);
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     const stateObj = this.stateObj;
 
     // We either need a `stateObj` or one override
@@ -56,7 +56,7 @@ export class StateBadge extends LitElement {
     }
 
     if (!this._showIcon) {
-      return html``;
+      return nothing;
     }
 
     const domain = stateObj ? computeStateDomain(stateObj) : undefined;

src/components/entity/state-info.ts

@@ -1,6 +1,6 @@
 import "@polymer/paper-tooltip/paper-tooltip";
 import type { HassEntity } from "home-assistant-js-websocket";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import { computeStateName } from "../../common/entity/compute_state_name";
 import { computeRTL } from "../../common/util/compute_rtl";
@@ -21,9 +21,9 @@ class StateInfo extends LitElement {
 
   @property() public color?: string;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass || !this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     const name = computeStateName(this.stateObj);

src/components/ha-addon-picker.ts

@@ -1,5 +1,5 @@
-import { html, LitElement, TemplateResult } from "lit";
 import { ComboBoxLitRenderer } from "@vaadin/combo-box/lit";
+import { html, LitElement, nothing } from "lit";
 import { customElement, property, query, state } from "lit/decorators";
 import { isComponentLoaded } from "../common/config/is_component_loaded";
 import { fireEvent } from "../common/dom/fire_event";
@@ -54,9 +54,9 @@ class HaAddonPicker extends LitElement {
     this._getAddons();
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._addons) {
-      return html``;
+      return nothing;
     }
     return html`
       <ha-combo-box

src/components/ha-areas-picker.ts

@@ -1,5 +1,5 @@
 import { HassEntity } from "home-assistant-js-websocket";
-import { css, html, LitElement, TemplateResult } from "lit";
+import { css, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import { fireEvent } from "../common/dom/fire_event";
 import { SubscribeMixin } from "../mixins/subscribe-mixin";
@@ -60,9 +60,9 @@ export class HaAreasPicker extends SubscribeMixin(LitElement) {
 
   @property({ type: Boolean }) public required?: boolean;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass) {
-      return html``;
+      return nothing;
     }
 
     const currentAreas = this._currentAreas;

src/components/ha-attributes.ts

@@ -1,5 +1,12 @@
 import { HassEntity } from "home-assistant-js-websocket";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import {
+  css,
+  CSSResultGroup,
+  html,
+  LitElement,
+  TemplateResult,
+  nothing,
+} from "lit";
 import { customElement, property, state } from "lit/decorators";
 import {
   formatAttributeName,
@@ -21,9 +28,9 @@ class HaAttributes extends LitElement {
 
   @state() private _expanded = false;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     const attributes = this.computeDisplayAttributes(
@@ -32,7 +39,7 @@ class HaAttributes extends LitElement {
       )
     );
     if (attributes.length === 0) {
-      return html``;
+      return nothing;
     }
 
     return html`

src/components/ha-blueprint-picker.ts

@@ -1,5 +1,5 @@
 import "@material/mwc-list/mwc-list-item";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import memoizeOne from "memoize-one";
 import { fireEvent } from "../common/dom/fire_event";
@@ -51,9 +51,9 @@ class HaBluePrintPicker extends LitElement {
     );
   });
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass) {
-      return html``;
+      return nothing;
     }
     return html`
       <ha-select

src/components/ha-camera-stream.ts

@@ -4,7 +4,7 @@ import {
   html,
   LitElement,
   PropertyValues,
-  TemplateResult,
+  nothing,
 } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { isComponentLoaded } from "../common/config/is_component_loaded";
@@ -76,9 +76,9 @@ export class HaCameraStream extends LitElement {
     this._connected = false;
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.stateObj) {
-      return html``;
+      return nothing;
     }
     if (__DEMO__ || this._shouldRenderMJPEG) {
       return html`<img
@@ -102,7 +102,7 @@ export class HaCameraStream extends LitElement {
             .url=${this._url}
             .posterUrl=${this._posterUrl}
           ></ha-hls-player>`
-        : html``;
+        : nothing;
     }
     if (this.stateObj.attributes.frontend_stream_type === STREAM_TYPE_WEB_RTC) {
       return html`<ha-web-rtc-player
@@ -115,7 +115,7 @@ export class HaCameraStream extends LitElement {
         .posterUrl=${this._posterUrl}
       ></ha-web-rtc-player>`;
     }
-    return html``;
+    return nothing;
   }
 
   private get _shouldRenderMJPEG() {

src/components/ha-card.ts

@@ -1,4 +1,4 @@
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 
 @customElement("ha-card")
@@ -70,11 +70,11 @@ export class HaCard extends LitElement {
     `;
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     return html`
       ${this.header
         ? html`<h1 class="card-header">${this.header}</h1>`
-        : html``}
+        : nothing}
       <slot></slot>
     `;
   }

src/components/ha-config-entry-picker.ts

@@ -1,16 +1,16 @@
 import "@material/mwc-list/mwc-list-item";
-import { html, LitElement, TemplateResult } from "lit";
 import { ComboBoxLitRenderer } from "@vaadin/combo-box/lit";
+import { html, LitElement, nothing } from "lit";
 import { customElement, property, query, state } from "lit/decorators";
 import { fireEvent } from "../common/dom/fire_event";
-import { PolymerChangedEvent } from "../polymer-types";
+import { caseInsensitiveStringCompare } from "../common/string/compare";
-import { HomeAssistant } from "../types";
-import type { HaComboBox } from "./ha-combo-box";
 import { ConfigEntry, getConfigEntries } from "../data/config_entries";
 import { domainToName } from "../data/integration";
-import { caseInsensitiveStringCompare } from "../common/string/compare";
+import { PolymerChangedEvent } from "../polymer-types";
+import { HomeAssistant } from "../types";
 import { brandsUrl } from "../util/brands-url";
 import "./ha-combo-box";
+import type { HaComboBox } from "./ha-combo-box";
 
 export interface ConfigEntryExtended extends ConfigEntry {
   localized_domain_name?: string;
@@ -72,9 +72,9 @@ class HaConfigEntryPicker extends LitElement {
     />
   </mwc-list-item>`;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._configEntries) {
-      return html``;
+      return nothing;
     }
     return html`
       <ha-combo-box

src/components/ha-cover-controls.ts

@@ -1,5 +1,5 @@
 import { mdiStop } from "@mdi/js";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import { classMap } from "lit/directives/class-map";
 import { computeCloseIcon, computeOpenIcon } from "../common/entity/cover_icon";
@@ -20,9 +20,9 @@ class HaCoverControls extends LitElement {
 
   @property({ attribute: false }) public stateObj!: CoverEntity;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     return html`

src/components/ha-cover-tilt-controls.ts

@@ -1,5 +1,5 @@
 import { mdiArrowBottomLeft, mdiArrowTopRight, mdiStop } from "@mdi/js";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import { classMap } from "lit/directives/class-map";
 import { supportsFeature } from "../common/entity/supports-feature";
@@ -19,9 +19,9 @@ class HaCoverTiltControls extends LitElement {
 
   @property({ attribute: false }) stateObj!: CoverEntity;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     return html` <ha-icon-button

src/components/ha-dialog-date-picker.ts

@@ -1,6 +1,6 @@
 import "@material/mwc-button/mwc-button";
 import "app-datepicker";
-import { css, html, LitElement } from "lit";
+import { css, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { fireEvent } from "../common/dom/fire_event";
 import { nextRender } from "../common/util/render-status";
@@ -38,7 +38,7 @@ export class HaDialogDatePicker extends LitElement {
 
   render() {
     if (!this._params) {
-      return html``;
+      return nothing;
     }
     return html`<ha-dialog open @closed=${this.closeDialog}>
       <app-datepicker

src/components/ha-icon.ts

@@ -5,7 +5,7 @@ import {
   html,
   LitElement,
   PropertyValues,
-  TemplateResult,
+  nothing,
 } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { fireEvent } from "../common/dom/fire_event";
@@ -156,9 +156,9 @@ export class HaIcon extends LitElement {
     }
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.icon) {
-      return html``;
+      return nothing;
     }
     if (this._legacy) {
       return html`<iron-icon .icon=${this.icon}></iron-icon>`;

src/components/ha-markdown.ts

@@ -1,4 +1,4 @@
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import "./ha-markdown-element";
 
@@ -15,9 +15,9 @@ export class HaMarkdown extends LitElement {
 
   @property({ type: Boolean }) public breaks = false;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.content) {
-      return html``;
+      return nothing;
     }
 
     return html`<ha-markdown-element

src/components/ha-network.ts

@@ -54,9 +54,9 @@ export class HaNetwork extends LitElement {
 
   @state() private _expanded?: boolean;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (this.networkConfig === undefined) {
-      return html``;
+      return nothing;
     }
     const configured_adapters = this.networkConfig.configured_adapters || [];
     return html`

src/components/ha-related-items.ts

@@ -5,7 +5,7 @@ import {
   html,
   LitElement,
   PropertyValues,
-  TemplateResult,
+  nothing,
 } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { fireEvent } from "../common/dom/fire_event";
@@ -70,9 +70,9 @@ export class HaRelatedItems extends SubscribeMixin(LitElement) {
     }
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._related) {
-      return html``;
+      return nothing;
     }
     if (Object.keys(this._related).length === 0) {
       return html`

src/components/ha-selector/ha-selector-area.ts

@@ -1,5 +1,5 @@
 import { HassEntity } from "home-assistant-js-websocket";
-import { html, LitElement, PropertyValues, TemplateResult } from "lit";
+import { html, LitElement, PropertyValues, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import memoizeOne from "memoize-one";
 import { ensureArray } from "../../common/array/ensure-array";
@@ -61,9 +61,9 @@ export class HaAreaSelector extends LitElement {
     }
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (this._hasIntegration(this.selector) && !this._entitySources) {
-      return html``;
+      return nothing;
     }
 
     if (!this.selector.area?.multiple) {

src/components/ha-selector/ha-selector-device.ts

@@ -1,5 +1,5 @@
 import { HassEntity } from "home-assistant-js-websocket";
-import { html, LitElement } from "lit";
+import { html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import memoizeOne from "memoize-one";
 import { ensureArray } from "../../common/array/ensure-array";
@@ -66,7 +66,7 @@ export class HaDeviceSelector extends LitElement {
 
   protected render() {
     if (this._hasIntegration(this.selector) && !this._entitySources) {
-      return html``;
+      return nothing;
     }
 
     if (!this.selector.device?.multiple) {

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

@@ -1,5 +1,5 @@
 import { HassEntity } from "home-assistant-js-websocket";
-import { html, LitElement, PropertyValues } from "lit";
+import { html, LitElement, PropertyValues, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { ensureArray } from "../../common/array/ensure-array";
 import {
@@ -39,7 +39,7 @@ export class HaEntitySelector extends LitElement {
 
   protected render() {
     if (this._hasIntegration(this.selector) && !this._entitySources) {
-      return html``;
+      return nothing;
     }
 
     if (!this.selector.entity?.multiple) {

src/components/ha-selector/ha-selector-target.ts

@@ -5,7 +5,7 @@ import {
   html,
   LitElement,
   PropertyValues,
-  TemplateResult,
+  nothing,
 } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import memoizeOne from "memoize-one";
@@ -70,9 +70,9 @@ export class HaTargetSelector extends LitElement {
     }
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (this._hasIntegration(this.selector) && !this._entitySources) {
-      return html``;
+      return nothing;
     }
 
     return html`<ha-target-picker

src/components/ha-sidebar.ts

@@ -29,6 +29,7 @@ import {
   html,
   LitElement,
   PropertyValues,
+  nothing,
 } from "lit";
 import { customElement, eventOptions, property, state } from "lit/decorators";
 import { classMap } from "lit/directives/class-map";
@@ -241,7 +242,7 @@ class HaSidebar extends SubscribeMixin(LitElement) {
 
   protected render() {
     if (!this.hass) {
-      return html``;
+      return nothing;
     }
 
     // prettier-ignore

src/components/ha-target-picker.ts

@@ -12,7 +12,7 @@ import {
 import "@polymer/paper-tooltip/paper-tooltip";
 import { ComboBoxLightOpenedChangedEvent } from "@vaadin/combo-box/vaadin-combo-box-light";
 import { HassEntity, HassServiceTarget } from "home-assistant-js-websocket";
-import { css, CSSResultGroup, html, LitElement, unsafeCSS } from "lit";
+import { css, CSSResultGroup, html, LitElement, unsafeCSS, nothing } from "lit";
 import { customElement, property, query, state } from "lit/decorators";
 import { classMap } from "lit/directives/class-map";
 import { ensureArray } from "../common/array/ensure-array";
@@ -278,7 +278,7 @@ export class HaTargetPicker extends LitElement {
 
   private _renderPicker() {
     if (!this._addMode) {
-      return html``;
+      return nothing;
     }
     return html`<mwc-menu-surface
       open

src/components/ha-tip.ts

@@ -1,6 +1,6 @@
 import { mdiLightbulbOutline } from "@mdi/js";
-import { css, html, LitElement, TemplateResult } from "lit";
+import { css, html, LitElement, nothing } from "lit";
-import { property, customElement } from "lit/decorators";
+import { customElement, property } from "lit/decorators";
 import { HomeAssistant } from "../types";
 
 import "./ha-svg-icon";
@@ -9,9 +9,9 @@ import "./ha-svg-icon";
 class HaTip extends LitElement {
   @property({ attribute: false }) public hass!: HomeAssistant;
 
-  public render(): TemplateResult {
+  public render() {
     if (!this.hass) {
-      return html``;
+      return nothing;
     }
 
     return html`

src/components/ha-yaml-editor.ts

@@ -1,5 +1,5 @@
 import { DEFAULT_SCHEMA, dump, load, Schema } from "js-yaml";
-import { html, LitElement, TemplateResult } from "lit";
+import { html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { fireEvent } from "../common/dom/fire_event";
 import type { HomeAssistant } from "../types";
@@ -56,9 +56,9 @@ export class HaYamlEditor extends LitElement {
     }
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (this._yaml === undefined) {
-      return html``;
+      return nothing;
     }
     return html`
       ${this.label

src/components/media-player/dialog-media-manage.ts

@@ -2,7 +2,7 @@ import { animate } from "@lit-labs/motion";
 import "@material/mwc-list/mwc-list";
 import "@material/mwc-list/mwc-list-item";
 import { mdiClose, mdiDelete } from "@mdi/js";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { repeat } from "lit/directives/repeat";
 import { fireEvent } from "../../common/dom/fire_event";
@@ -18,11 +18,11 @@ import {
 import { showConfirmationDialog } from "../../dialogs/generic/show-dialog-box";
 import { haStyleDialog } from "../../resources/styles";
 import type { HomeAssistant } from "../../types";
+import "../ha-check-list-item";
 import "../ha-circular-progress";
 import "../ha-dialog";
 import "../ha-header-bar";
 import "../ha-svg-icon";
-import "../ha-check-list-item";
 import "./ha-media-player-browse";
 import "./ha-media-upload-button";
 import type { MediaManageDialogParams } from "./show-media-manage-dialog";
@@ -60,9 +60,9 @@ class DialogMediaManage extends LitElement {
     fireEvent(this, "dialog-closed", { dialog: this.localName });
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._params) {
-      return html``;
+      return nothing;
     }
 
     const children =

src/components/media-player/dialog-media-player-browse.ts

@@ -1,6 +1,5 @@
-import "../ha-header-bar";
 import { mdiArrowLeft, mdiClose } from "@mdi/js";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property, query, state } from "lit/decorators";
 import { fireEvent, HASSDomEvent } from "../../common/dom/fire_event";
 import { computeRTLDirection } from "../../common/util/compute_rtl";
@@ -12,8 +11,9 @@ import type {
 import { haStyleDialog } from "../../resources/styles";
 import type { HomeAssistant } from "../../types";
 import "../ha-dialog";
-import "./ha-media-player-browse";
+import "../ha-header-bar";
 import "./ha-media-manage-button";
+import "./ha-media-player-browse";
 import type {
   HaMediaPlayerBrowse,
   MediaPlayerItemId,
@@ -49,9 +49,9 @@ class DialogMediaPlayerBrowse extends LitElement {
     fireEvent(this, "dialog-closed", { dialog: this.localName });
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._params || !this._navigateIds) {
-      return html``;
+      return nothing;
     }
 
     return html`

src/components/media-player/ha-media-manage-button.ts

@@ -1,13 +1,13 @@
-import { mdiFolderEdit } from "@mdi/js";
 import "@material/mwc-button";
-import { css, html, LitElement, TemplateResult } from "lit";
+import { mdiFolderEdit } from "@mdi/js";
+import { css, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
+import { fireEvent } from "../../common/dom/fire_event";
 import { MediaPlayerItem } from "../../data/media-player";
-import "../ha-svg-icon";
 import { isLocalMediaSourceContentId } from "../../data/media_source";
 import type { HomeAssistant } from "../../types";
+import "../ha-svg-icon";
 import { showMediaManageDialog } from "./show-media-manage-dialog";
-import { fireEvent } from "../../common/dom/fire_event";
 
 declare global {
   interface HASSDomEvents {
@@ -23,12 +23,12 @@ class MediaManageButton extends LitElement {
 
   @state() _uploading = 0;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (
       !this.currentItem ||
       !isLocalMediaSourceContentId(this.currentItem.media_content_id || "")
     ) {
-      return html``;
+      return nothing;
     }
     return html`
       <mwc-button

src/components/media-player/ha-media-player-browse.ts

@@ -13,6 +13,7 @@ import {
   LitElement,
   PropertyValues,
   TemplateResult,
+  nothing,
 } from "lit";
 import {
   customElement,
@@ -311,7 +312,7 @@ export class HaMediaPlayerBrowse extends LitElement {
     }
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (this._error) {
       return html`
         <div class="container">
@@ -388,7 +389,7 @@ export class HaMediaPlayerBrowse extends LitElement {
                                     : ""}
                                 </div>
                               `
-                            : html``}
+                            : nothing}
                           <div class="header-info">
                             <div class="breadcrumb">
                               <h1 class="title">${currentItem.title}</h1>

src/components/media-player/ha-media-upload-button.ts

@@ -1,17 +1,17 @@
-import { mdiUpload } from "@mdi/js";
 import "@material/mwc-button";
-import { css, html, LitElement, TemplateResult } from "lit";
+import { mdiUpload } from "@mdi/js";
+import { css, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { fireEvent } from "../../common/dom/fire_event";
 import { MediaPlayerItem } from "../../data/media-player";
-import "../ha-circular-progress";
-import "../ha-svg-icon";
 import {
   isLocalMediaSourceContentId,
   uploadLocalMedia,
 } from "../../data/media_source";
-import type { HomeAssistant } from "../../types";
 import { showAlertDialog } from "../../dialogs/generic/show-dialog-box";
+import type { HomeAssistant } from "../../types";
+import "../ha-circular-progress";
+import "../ha-svg-icon";
 
 declare global {
   interface HASSDomEvents {
@@ -28,12 +28,12 @@ class MediaUploadButton extends LitElement {
 
   @state() _uploading = 0;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (
       !this.currentItem ||
       !isLocalMediaSourceContentId(this.currentItem.media_content_id || "")
     ) {
-      return html``;
+      return nothing;
     }
     return html`
       <mwc-button

src/components/trace/hat-trace-timeline.ts

@@ -14,6 +14,7 @@ import {
   LitElement,
   PropertyValues,
   TemplateResult,
+  nothing,
 } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { ifDefined } from "lit/directives/if-defined";
@@ -595,9 +596,9 @@ export class HaAutomationTracer extends LitElement {
     ];
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.trace) {
-      return html``;
+      return nothing;
     }
 
     const entries: TemplateResult[] = [];

src/components/user/ha-person-badge.ts

@@ -1,4 +1,4 @@
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import { classMap } from "lit/directives/class-map";
 import { styleMap } from "lit/directives/style-map";
@@ -9,9 +9,9 @@ import { computeUserInitials } from "../../data/user";
 class PersonBadge extends LitElement {
   @property({ attribute: false }) public person?: Person;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.person) {
-      return html``;
+      return nothing;
     }
 
     const picture = this.person.picture;

src/components/user/ha-user-badge.ts

@@ -4,7 +4,7 @@ import {
   html,
   LitElement,
   PropertyValues,
-  TemplateResult,
+  nothing,
 } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { classMap } from "lit/directives/class-map";
@@ -47,9 +47,9 @@ class UserBadge extends LitElement {
     }
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass || !this.user) {
-      return html``;
+      return nothing;
     }
     const picture = this._personPicture;
 

src/components/user/ha-users-picker.ts

@@ -1,5 +1,5 @@
 import { mdiClose } from "@mdi/js";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import { guard } from "lit/directives/guard";
 import memoizeOne from "memoize-one";
@@ -34,9 +34,9 @@ class HaUsersPickerLight extends LitElement {
     }
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass || !this.users) {
-      return html``;
+      return nothing;
     }
 
     const notSelectedUsers = this._notSelectedUsers(this.users, this.value);

src/dialogs/aliases/dialog-aliases.ts

@@ -1,6 +1,6 @@
 import "@material/mwc-button/mwc-button";
 import { mdiDeleteOutline, mdiPlus } from "@mdi/js";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { fireEvent } from "../../common/dom/fire_event";
 import "../../components/ha-alert";
@@ -40,9 +40,9 @@ class DialogAliases extends LitElement {
     fireEvent(this, "dialog-closed", { dialog: this.localName });
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._params) {
-      return html``;
+      return nothing;
     }
 
     return html`

src/dialogs/config-entry-system-options/dialog-config-entry-system-options.ts

@@ -1,5 +1,5 @@
 import "@material/mwc-button/mwc-button";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { fireEvent } from "../../common/dom/fire_event";
 import { computeRTLDirection } from "../../common/util/compute_rtl";
@@ -45,9 +45,9 @@ class DialogConfigEntrySystemOptions extends LitElement {
     fireEvent(this, "dialog-closed", { dialog: this.localName });
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._params) {
-      return html``;
+      return nothing;
     }
 
     return html`

src/dialogs/config-flow/dialog-data-entry-flow.ts

@@ -7,7 +7,7 @@ import {
   html,
   LitElement,
   PropertyValues,
-  TemplateResult,
+  nothing,
 } from "lit";
 import { customElement, state } from "lit/decorators";
 import { fireEvent, HASSDomEvent } from "../../common/dom/fire_event";
@@ -202,9 +202,9 @@ class DataEntryFlowDialog extends LitElement {
     fireEvent(this, "dialog-closed", { dialog: this.localName });
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._params) {
-      return html``;
+      return nothing;
     }
 
     return html`

src/dialogs/config-flow/step-flow-abort.ts

@@ -1,19 +1,13 @@
 import "@material/mwc-button";
-import {
+import { CSSResultGroup, html, LitElement, PropertyValues, nothing } from "lit";
-  CSSResultGroup,
-  html,
-  LitElement,
-  TemplateResult,
-  PropertyValues,
-} from "lit";
 import { customElement, property } from "lit/decorators";
 import { fireEvent } from "../../common/dom/fire_event";
 import { DataEntryFlowStepAbort } from "../../data/data_entry_flow";
-import { HomeAssistant } from "../../types";
 import { showAddApplicationCredentialDialog } from "../../panels/config/application_credentials/show-dialog-add-application-credential";
-import { configFlowContentStyles } from "./styles";
+import { HomeAssistant } from "../../types";
-import { DataEntryFlowDialogParams } from "./show-dialog-data-entry-flow";
 import { showConfigFlowDialog } from "./show-dialog-config-flow";
+import { DataEntryFlowDialogParams } from "./show-dialog-data-entry-flow";
+import { configFlowContentStyles } from "./styles";
 
 @customElement("step-flow-abort")
 class StepFlowAbort extends LitElement {
@@ -32,9 +26,9 @@ class StepFlowAbort extends LitElement {
     }
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (this.step.reason === "missing_credentials") {
-      return html``;
+      return nothing;
     }
     return html`
       <h2>${this.hass.localize(`component.${this.domain}.title`)}</h2>

src/dialogs/domain-toggler/dialog-domain-toggler.ts

@@ -1,5 +1,5 @@
 import "@material/mwc-button/mwc-button";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, state } from "lit/decorators";
 import { fireEvent } from "../../common/dom/fire_event";
 import { createCloseHeading } from "../../components/ha-dialog";
@@ -29,9 +29,9 @@ class DomainTogglerDialog
     fireEvent(this, "dialog-closed", { dialog: this.localName });
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._params) {
-      return html``;
+      return nothing;
     }
 
     const domains = this._params.domains

src/dialogs/generic/dialog-box.ts

@@ -1,6 +1,6 @@
 import "@material/mwc-button/mwc-button";
 import { mdiAlertOutline } from "@mdi/js";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property, query, state } from "lit/decorators";
 import { classMap } from "lit/directives/class-map";
 import { ifDefined } from "lit/directives/if-defined";
@@ -35,9 +35,9 @@ class DialogBox extends LitElement {
     return true;
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._params) {
-      return html``;
+      return nothing;
     }
 
     const confirmPrompt = this._params.confirmation || this._params.prompt;

src/dialogs/more-info/components/lights/ha-more-info-view-light-color-picker.ts

@@ -8,7 +8,7 @@ import {
   html,
   LitElement,
   PropertyValues,
-  TemplateResult,
+  nothing,
 } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import "../../../../components/ha-button-toggle-group";
@@ -62,9 +62,9 @@ class MoreInfoViewLightColorPicker extends LitElement {
       : undefined;
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.params || !this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     const supportsRgbww = lightSupportsColorMode(

src/dialogs/more-info/controls/more-info-alarm_control_panel.ts

@@ -1,15 +1,15 @@
 import "@material/mwc-button";
 import type { HassEntity } from "home-assistant-js-websocket";
-import { css, html, LitElement, PropertyValues, TemplateResult } from "lit";
+import { css, html, LitElement, PropertyValues, nothing } from "lit";
-import { customElement, property, state, query } from "lit/decorators";
+import { customElement, property, query, state } from "lit/decorators";
 import { classMap } from "lit/directives/class-map";
-import "../../../components/ha-textfield";
 import { supportsFeature } from "../../../common/entity/supports-feature";
+import "../../../components/ha-textfield";
 import type { HaTextField } from "../../../components/ha-textfield";
 import {
+  AlarmControlPanelEntityFeature,
   callAlarmAction,
   FORMAT_NUMBER,
-  AlarmControlPanelEntityFeature,
 } from "../../../data/alarm_control_panel";
 import type { HomeAssistant } from "../../../types";
 
@@ -67,9 +67,9 @@ export class MoreInfoAlarmControlPanel extends LitElement {
     }
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass || !this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     return html`

src/dialogs/more-info/controls/more-info-automation.ts

@@ -1,6 +1,6 @@
 import "@material/mwc-button";
 import { HassEntity } from "home-assistant-js-websocket";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import "../../../components/ha-relative-time";
 import { triggerAutomationActions } from "../../../data/automation";
@@ -13,9 +13,9 @@ class MoreInfoAutomation extends LitElement {
 
   @property({ attribute: false }) public stateObj?: HassEntity;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass || !this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     return html`

src/dialogs/more-info/controls/more-info-camera.ts

@@ -1,4 +1,4 @@
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { property, state } from "lit/decorators";
 import "../../../components/ha-camera-stream";
 import { CameraEntity } from "../../../data/camera";
@@ -21,9 +21,9 @@ class MoreInfoCamera extends LitElement {
     this._attached = false;
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this._attached || !this.hass || !this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     return html`

src/dialogs/more-info/controls/more-info-climate.ts

@@ -5,7 +5,7 @@ import {
   html,
   LitElement,
   PropertyValues,
-  TemplateResult,
+  nothing,
 } from "lit";
 import { property } from "lit/decorators";
 import { classMap } from "lit/directives/class-map";
@@ -36,9 +36,9 @@ class MoreInfoClimate extends LitElement {
 
   private _resizeDebounce?: number;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     const hass = this.hass;

src/dialogs/more-info/controls/more-info-configurator.ts

@@ -1,6 +1,6 @@
 import "@material/mwc-button";
 import type { HassEntity } from "home-assistant-js-websocket";
-import { css, html, LitElement, TemplateResult } from "lit";
+import { css, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import "../../../components/ha-alert";
 import "../../../components/ha-circular-progress";
@@ -18,9 +18,9 @@ export class MoreInfoConfigurator extends LitElement {
 
   private _fieldInput = {};
 
-  protected render(): TemplateResult {
+  protected render() {
     if (this.stateObj?.state !== "configure") {
-      return html``;
+      return nothing;
     }
 
     return html`

src/dialogs/more-info/controls/more-info-counter.ts

@@ -1,6 +1,6 @@
 import "@material/mwc-button";
 import { HassEntity } from "home-assistant-js-websocket";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import { isUnavailableState } from "../../../data/entity";
 import { HomeAssistant } from "../../../types";
@@ -11,9 +11,9 @@ class MoreInfoCounter extends LitElement {
 
   @property() public stateObj?: HassEntity;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass || !this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     const disabled = isUnavailableState(this.stateObj!.state);

src/dialogs/more-info/controls/more-info-cover.ts

@@ -1,4 +1,4 @@
-import { css, CSSResult, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResult, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import { attributeClassNames } from "../../../common/entity/attribute_class_names";
 import {
@@ -30,9 +30,9 @@ class MoreInfoCover extends LitElement {
 
   @property({ attribute: false }) public stateObj!: CoverEntity;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     const _isTiltOnly = isTiltOnly(this.stateObj);
@@ -71,7 +71,7 @@ class MoreInfoCover extends LitElement {
                       slot="extra"
                       .stateObj=${this.stateObj}
                     ></ha-cover-tilt-controls> `
-                  : html``}
+                  : nothing}
               </ha-labeled-slider>`
             : !_isTiltOnly
             ? html`
@@ -83,7 +83,7 @@ class MoreInfoCover extends LitElement {
                   .stateObj=${this.stateObj}
                 ></ha-cover-tilt-controls>
               `
-            : html``}
+            : nothing}
         </div>
       </div>
       <ha-attributes

src/dialogs/more-info/controls/more-info-default.ts

@@ -1,5 +1,5 @@
 import { HassEntity } from "home-assistant-js-websocket";
-import { html, LitElement, TemplateResult } from "lit";
+import { html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import "../../../components/ha-attributes";
 import { HomeAssistant } from "../../../types";
@@ -10,9 +10,9 @@ class MoreInfoDefault extends LitElement {
 
   @property() public stateObj?: HassEntity;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass || !this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     return html`<ha-attributes

src/dialogs/more-info/controls/more-info-group.ts

@@ -5,7 +5,7 @@ import {
   html,
   LitElement,
   PropertyValues,
-  TemplateResult,
+  nothing,
 } from "lit";
 import { property, state } from "lit/decorators";
 import { dynamicElement } from "../../../common/dom/dynamic-element-directive";
@@ -70,9 +70,9 @@ class MoreInfoGroup extends LitElement {
     }
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass || !this.stateObj) {
-      return html``;
+      return nothing;
     }
     return html`${this._moreInfoType
       ? dynamicElement(this._moreInfoType, {

src/dialogs/more-info/controls/more-info-humidifier.ts

@@ -5,7 +5,7 @@ import {
   html,
   LitElement,
   PropertyValues,
-  TemplateResult,
+  nothing,
 } from "lit";
 import { property } from "lit/decorators";
 import { classMap } from "lit/directives/class-map";
@@ -29,9 +29,9 @@ class MoreInfoHumidifier extends LitElement {
 
   private _resizeDebounce?: number;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     const hass = this.hass;

src/dialogs/more-info/controls/more-info-input_datetime.ts

@@ -1,5 +1,5 @@
 import { HassEntity } from "home-assistant-js-websocket";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import "../../../components/ha-date-input";
 import "../../../components/ha-time-input";
@@ -16,9 +16,9 @@ class MoreInfoInputDatetime extends LitElement {
 
   @property({ attribute: false }) public stateObj?: HassEntity;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     return html`

src/dialogs/more-info/controls/more-info-lock.ts

@@ -1,6 +1,6 @@
 import "@material/mwc-button";
 import type { HassEntity } from "home-assistant-js-websocket";
-import { css, html, LitElement, TemplateResult } from "lit";
+import { css, html, LitElement, nothing } from "lit";
 import { customElement, property, query } from "lit/decorators";
 import "../../../components/ha-attributes";
 import "../../../components/ha-textfield";
@@ -15,9 +15,9 @@ class MoreInfoLock extends LitElement {
 
   @query("ha-textfield") private _textfield?: HaTextField;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass || !this.stateObj) {
-      return html``;
+      return nothing;
     }
     return html`
       ${this.stateObj.attributes.code_format

src/dialogs/more-info/controls/more-info-media_player.ts

@@ -9,7 +9,7 @@ import {
   mdiVolumeOff,
   mdiVolumePlus,
 } from "@mdi/js";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import { stopPropagation } from "../../../common/dom/stop_propagation";
 import { supportsFeature } from "../../../common/entity/supports-feature";
@@ -36,9 +36,9 @@ class MoreInfoMediaPlayer extends LitElement {
 
   @property({ attribute: false }) public stateObj?: MediaPlayerEntity;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     const stateObj = this.stateObj;

src/dialogs/more-info/controls/more-info-person.ts

@@ -1,6 +1,6 @@
 import "@material/mwc-button";
 import { HassEntity } from "home-assistant-js-websocket";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import memoizeOne from "memoize-one";
 import { fireEvent } from "../../../common/dom/fire_event";
@@ -17,9 +17,9 @@ class MoreInfoPerson extends LitElement {
 
   private _entityArray = memoizeOne((entityId: string) => [entityId]);
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass || !this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     return html`

src/dialogs/more-info/controls/more-info-remote.ts

@@ -1,12 +1,12 @@
-import { html, LitElement, TemplateResult } from "lit";
+import "@material/mwc-list/mwc-list";
+import "@material/mwc-list/mwc-list-item";
+import { html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
+import { stopPropagation } from "../../../common/dom/stop_propagation";
 import { supportsFeature } from "../../../common/entity/supports-feature";
 import "../../../components/ha-attributes";
 import { RemoteEntity, REMOTE_SUPPORT_ACTIVITY } from "../../../data/remote";
 import { HomeAssistant } from "../../../types";
-import "@material/mwc-list/mwc-list-item";
-import "@material/mwc-list/mwc-list";
-import { stopPropagation } from "../../../common/dom/stop_propagation";
 
 const filterExtraAttributes = "activity_list,current_activity";
 
@@ -16,9 +16,9 @@ class MoreInfoRemote extends LitElement {
 
   @property() public stateObj?: RemoteEntity;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass || !this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     const stateObj = this.stateObj;

src/dialogs/more-info/controls/more-info-script.ts

@@ -1,5 +1,5 @@
 import { HassEntity } from "home-assistant-js-websocket";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import "../../../components/ha-relative-time";
 import { HomeAssistant } from "../../../types";
@@ -10,9 +10,9 @@ class MoreInfoScript extends LitElement {
 
   @property() public stateObj?: HassEntity;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass || !this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     return html`

src/dialogs/more-info/controls/more-info-sun.ts

@@ -1,5 +1,5 @@
 import { HassEntity } from "home-assistant-js-websocket";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import { formatTime } from "../../../common/datetime/format_time";
 import { formatNumber } from "../../../common/number/format_number";
@@ -12,9 +12,9 @@ class MoreInfoSun extends LitElement {
 
   @property() public stateObj?: HassEntity;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass || !this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     const risingDate = new Date(this.stateObj.attributes.next_rising);

src/dialogs/more-info/controls/more-info-timer.ts

@@ -1,5 +1,5 @@
 import "@material/mwc-button";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import "../../../components/ha-attributes";
 import { TimerEntity } from "../../../data/timer";
@@ -11,9 +11,9 @@ class MoreInfoTimer extends LitElement {
 
   @property() public stateObj?: TimerEntity;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass || !this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     return html`

src/dialogs/more-info/controls/more-info-update.ts

@@ -1,12 +1,13 @@
-import "../../../components/ha-alert";
-import "../../../components/ha-faded";
 import "@material/mwc-button/mwc-button";
 import "@material/mwc-linear-progress/mwc-linear-progress";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
+import { BINARY_STATE_OFF } from "../../../common/const";
 import { supportsFeature } from "../../../common/entity/supports-feature";
+import "../../../components/ha-alert";
 import "../../../components/ha-checkbox";
 import "../../../components/ha-circular-progress";
+import "../../../components/ha-faded";
 import "../../../components/ha-formfield";
 import "../../../components/ha-markdown";
 import { isUnavailableState } from "../../../data/entity";
@@ -21,7 +22,6 @@ import {
   UPDATE_SUPPORT_SPECIFIC_VERSION,
 } from "../../../data/update";
 import type { HomeAssistant } from "../../../types";
-import { BINARY_STATE_OFF } from "../../../common/const";
 
 @customElement("more-info-update")
 class MoreInfoUpdate extends LitElement {
@@ -33,13 +33,13 @@ class MoreInfoUpdate extends LitElement {
 
   @state() private _error?: string;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (
       !this.hass ||
       !this.stateObj ||
       isUnavailableState(this.stateObj.state)
     ) {
-      return html``;
+      return nothing;
     }
 
     const skippedVersion =

src/dialogs/more-info/controls/more-info-vacuum.ts

@@ -9,7 +9,7 @@ import {
   mdiStop,
   mdiTargetVariant,
 } from "@mdi/js";
-import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
+import { css, CSSResultGroup, html, LitElement, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import { stopPropagation } from "../../../common/dom/stop_propagation";
 import { supportsFeature } from "../../../common/entity/supports-feature";
@@ -90,9 +90,9 @@ class MoreInfoVacuum extends LitElement {
 
   @property() public stateObj?: VacuumEntity;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass || !this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     const stateObj = this.stateObj;

src/dialogs/more-info/controls/more-info-weather.ts

@@ -11,7 +11,7 @@ import {
   html,
   LitElement,
   PropertyValues,
-  TemplateResult,
+  nothing,
 } from "lit";
 import { customElement, property } from "lit/decorators";
 import { formatDateWeekdayDay } from "../../../common/datetime/format_date";
@@ -50,9 +50,9 @@ class MoreInfoWeather extends LitElement {
     return false;
   }
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.hass || !this.stateObj) {
-      return html``;
+      return nothing;
     }
 
     const hourly = isForecastHourly(this.stateObj.attributes.forecast);

src/dialogs/more-info/ha-more-info-history.ts

@@ -1,24 +1,24 @@
 import { startOfYesterday, subHours } from "date-fns/esm";
-import { css, html, LitElement, PropertyValues, TemplateResult } from "lit";
+import { css, html, LitElement, PropertyValues, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { isComponentLoaded } from "../../common/config/is_component_loaded";
 import { fireEvent } from "../../common/dom/fire_event";
+import { computeDomain } from "../../common/entity/compute_domain";
 import "../../components/chart/state-history-charts";
+import "../../components/chart/statistics-chart";
 import {
+  computeHistory,
   HistoryResult,
   subscribeHistoryStatesTimeWindow,
-  computeHistory,
 } from "../../data/history";
 import {
   fetchStatistics,
   getStatisticMetadata,
   Statistics,
-  StatisticsTypes,
   StatisticsMetaData,
+  StatisticsTypes,
 } from "../../data/recorder";
 import { HomeAssistant } from "../../types";
-import "../../components/chart/statistics-chart";
-import { computeDomain } from "../../common/entity/compute_domain";
 
 declare global {
   interface HASSDomEvents {
@@ -50,9 +50,9 @@ export class MoreInfoHistory extends LitElement {
 
   private _metadata?: Record<string, StatisticsMetaData>;
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!this.entityId) {
-      return html``;
+      return nothing;
     }
 
     return html` ${isComponentLoaded(this.hass, "history")

src/dialogs/more-info/ha-more-info-logbook.ts

@@ -1,5 +1,5 @@
 import { startOfYesterday } from "date-fns/esm";
-import { css, html, LitElement, PropertyValues, TemplateResult } from "lit";
+import { css, html, LitElement, PropertyValues, nothing } from "lit";
 import { customElement, property } from "lit/decorators";
 import memoizeOne from "memoize-one";
 import { isComponentLoaded } from "../../common/config/is_component_loaded";
@@ -19,14 +19,14 @@ export class MoreInfoLogbook extends LitElement {
 
   private _entityIdAsList = memoizeOne((entityId: string) => [entityId]);
 
-  protected render(): TemplateResult {
+  protected render() {
     if (!isComponentLoaded(this.hass, "logbook") || !this.entityId) {
-      return html``;
+      return nothing;
     }
     const stateObj = this.hass.states[this.entityId];
 
     if (!stateObj) {
-      return html``;
+      return nothing;
     }
 
     return html`