test: Add browser based tests for keyboard focus handling (#2647)

tests/browser/ha-element-stubs.ts

@@ -1,4 +1,5 @@
 import { css, html, LitElement, type TemplateResult } from 'lit';
+import { property } from 'lit/decorators.js';
 
 import { SIDE_LOADED_ELEMENTS } from '../../src/ha/side-load-ha-elements';
 
@@ -79,8 +80,11 @@ class HACardStub extends HAElementStub {
  * A round tap target sized by `--ha-icon-button-size`, which is how Home
  * Assistant's own icon button sizes itself and what the card sets to lay its
  * menu out. Without it a button is only as big as whatever it contains.
+ *
+ * Home Assistant draws a real `<button>` within, so a menu button takes focus
+ * when it is pressed, can be tabbed to, and ignores a press while disabled.
  */
-class HAIconButtonStub extends HAElementStub {
+class HAIconButtonStub extends LitElement {
   static styles = css`
     :host {
       display: inline-flex;
@@ -92,7 +96,26 @@ class HAIconButtonStub extends HAElementStub {
       box-sizing: border-box;
       outline: none;
     }
+    button {
+      align-items: center;
+      background: none;
+      border: none;
+      color: inherit;
+      cursor: pointer;
+      display: flex;
+      height: 100%;
+      justify-content: center;
+      padding: 0;
+      width: 100%;
+    }
   `;
+
+  @property({ type: Boolean })
+  public disabled = false;
+
+  protected render(): TemplateResult {
+    return html`<button ?disabled=${this.disabled}><slot></slot></button>`;
+  }
 }
 
 /**
@@ -110,15 +133,58 @@ class HAIconStub extends LitElement {
   `;
 }
 
+interface PictureElementConfig {
+  type: string;
+}
+
+interface ConditionalElementConfig {
+  elements?: PictureElementConfig[];
+}
+
+// Every Home Assistant element takes its own shape of configuration through the
+// same call, and nothing here reads what is passed.
+interface ConfigurableElement extends HTMLElement {
+  setConfig(config: unknown): void;
+}
+
+const isConfigurable = (element: HTMLElement): element is ConfigurableElement =>
+  'setConfig' in element;
+
+const CUSTOM_ELEMENT_PREFIX = 'custom:';
+const CARD_ELEMENT_PREFIX = `${CUSTOM_ELEMENT_PREFIX}advanced-camera-card-`;
+
 /**
  * Home Assistant's conditional picture element, which the card builds one of on
  * every mount to host whatever picture elements are configured.
+ *
+ * Home Assistant creates one element per entry. The card's own menu and status
+ * bar items are elements that ask to be added when they are connected, so
+ * without that a configured menu button never reaches the menu.
+ *
+ * Only the card's own elements are created here. Other elements (e.g. Home
+ * Assistant's `icon` or `image`) are skipped, so a test that needs one must add
+ * it to this stub first.
  */
 class HuiConditionalElementStub extends HTMLElement {
   public hass?: unknown;
 
-  public setConfig(): void {
+  public setConfig(config: ConditionalElementConfig): void {
-    // The card only needs the call to succeed; nothing renders from it here.
+    this.replaceChildren();
+
+    for (const element of config.elements ?? []) {
+      if (!element.type.startsWith(CARD_ELEMENT_PREFIX)) {
+        continue;
+      }
+
+      const child = document.createElement(
+        // Example: custom:advanced-camera-card-menu-icon -> advanced-camera-card-menu-icon
+        element.type.slice(CUSTOM_ELEMENT_PREFIX.length),
+      );
+      if (isConfigurable(child)) {
+        child.setConfig(element);
+      }
+      this.append(child);
+    }
   }
 }
 

tests/browser/mounted-card.ts

@@ -5,7 +5,7 @@ import type { AdvancedCameraCard } from '../../src/card';
 import type { RawAdvancedCameraCardConfig } from '../../src/config/types';
 import type { FakeEntityOptions, FakeHASS } from './fake-hass';
 import { defineHAElementStubs } from './ha-element-stubs';
-import { deepQuery, deepQueryAll } from './test-utils';
+import { clickElement, deepQuery, deepQueryAll } from './test-utils';
 
 // Home Assistant's masonry columns are `max-width: 500px`, so this is the width
 // a card usually gets. The card derives height from the media it is showing.
@@ -35,6 +35,19 @@ interface ConsoleEntry {
   args: unknown[];
 }
 
+interface ConsoleWaiter {
+  // The number of occurrences required to satisfy this waiter.
+  count: number;
+  level: ConsoleLevel;
+  message: RegExp;
+  resolve: () => void;
+}
+
+interface ConsoleWaiterOptions {
+  count?: number;
+  level?: ConsoleLevel;
+}
+
 const CONSOLE_LEVELS = ['debug', 'error', 'info', 'log', 'warn'] as const;
 type ConsoleLevel = (typeof CONSOLE_LEVELS)[number];
 
@@ -154,12 +167,15 @@ class ConsoleLedger {
   private _entries: ConsoleEntry[] = [];
   private _originals = new Map<ConsoleLevel, (...args: unknown[]) => void>();
 
+  private _waiting: ConsoleWaiter[] = [];
+
   constructor() {
     for (const level of CONSOLE_LEVELS) {
       const original = console[level];
       this._originals.set(level, original);
       console[level] = (...args: unknown[]): void => {
         this._entries.push({ level, args });
+        this._resolveWaiters();
         original(...args);
       };
     }
@@ -175,12 +191,55 @@ class ConsoleLedger {
     return this.getEntries(level).map((entry) => entry.args.map(String).join(' '));
   }
 
+  public countMessages(message: RegExp, level: ConsoleLevel = 'info'): number {
+    return this.getMessages(level).filter((written) => message.test(written)).length;
+  }
+
+  /**
+   * Wait until a message has been written. The card acts on what a test does to
+   * it without waiting to be asked, so a test that presses a key and reads the
+   * log on the next line usually finds nothing there yet.
+   */
+  public async waitForMessage(
+    message: RegExp,
+    options?: ConsoleWaiterOptions,
+  ): Promise<void> {
+    const waiter = {
+      count: options?.count ?? 1,
+      level: options?.level ?? 'info',
+      message,
+    };
+
+    if (this._isSatisfied(waiter)) {
+      return;
+    }
+
+    return await new Promise<void>((resolve) => {
+      this._waiting.push({ ...waiter, resolve });
+    });
+  }
+
+  private _isSatisfied(waiter: Omit<ConsoleWaiter, 'resolve'>): boolean {
+    return this.countMessages(waiter.message, waiter.level) >= waiter.count;
+  }
+
+  private _resolveWaiters(): void {
+    this._waiting = this._waiting.filter((waiter) => {
+      if (!this._isSatisfied(waiter)) {
+        return true;
+      }
+      waiter.resolve();
+      return false;
+    });
+  }
+
   public destroy(): void {
     for (const [level, original] of this._originals) {
       console[level] = original;
     }
     this._originals.clear();
     this._entries = [];
+    this._waiting = [];
   }
 }
 
@@ -195,6 +254,11 @@ export interface MountOptions {
   width?: string;
   height?: string;
 
+  // Where that container is placed, as CSS lengths from the page's top left
+  // corner. The page grows to reach it, so a card put beyond the window can
+  // only be brought into view by scrolling.
+  position?: { top?: string; left?: string };
+
   // Console errors required to be logged.
   expectedConsoleErrors?: RegExp[];
 
@@ -246,6 +310,11 @@ export class MountedCard {
     if (options?.height) {
       this._container.style.height = options.height;
     }
+    if (options?.position) {
+      this._container.style.position = 'absolute';
+      this._container.style.top = options.position.top ?? '0';
+      this._container.style.left = options.position.left ?? '0';
+    }
     document.body.append(this._container);
 
     // Before the card exists, so that nothing it does during its first render is
@@ -378,12 +447,16 @@ export class MountedCard {
   public async clickControl(name: string): Promise<void> {
     const control = await this._findControl(name);
 
-    control.click();
+    await clickElement(control);
   }
 
   /**
    * Press and keep holding a control until the card takes it as a hold, which
    * is a second action several controls carry alongside their tap.
+   *
+   * Assembled from events rather than driven with a real pointer, because
+   * `userEvent` offers whole gestures only (click, hover, drag) and none of
+   * them stops part way through a press.
    */
   public async holdControl(name: string): Promise<void> {
     const control = await this._findControl(name);

tests/browser/test-utils.ts

@@ -1,5 +1,8 @@
+import { userEvent } from 'vitest/browser';
+
 import type { RawAdvancedCameraCardConfig } from '../../src/config/types';
 import type { MediaLoadedInfoEventDetail } from '../../src/types';
+import { createLogAction } from '../../src/utils/action';
 import { FakeHASS, type FakeEntityOptions } from './fake-hass';
 
 export const STILL_CAMERA_ENTITY = 'camera.office';
@@ -111,6 +114,20 @@ export const createStillImageCardConfig = (
   ...overrides,
 });
 
+// What an initialized card writes, as the pattern the console is searched for.
+export const CARD_INITIALIZED_MESSAGE = /card initialized/;
+
+/**
+ * An automation that reports every time the card finishes initializing. A card
+ * announces nothing else when it is ready to be acted on, and it initializes
+ * again each time it returns to the page or Home Assistant comes back, so a
+ * test that acts on a card too early sees nothing happen.
+ */
+export const createInitializedAutomation = (): RawAdvancedCameraCardConfig => ({
+  triggers: [{ trigger: 'initialized' }],
+  actions: [createLogAction(CARD_INITIALIZED_MESSAGE.source)],
+});
+
 // `querySelectorAll` does not look inside a shadow root, so a full search has
 // to step through them a level at a time. The node's own root counts because a
 // Lit element renders into that, not into its children.
@@ -183,3 +200,54 @@ export const isLiveMediaShowing = (root: ParentNode): boolean =>
   deepQueryAll(root, 'advanced-camera-card-live-provider').some(
     (provider) => !!deepQuery(provider, MEDIA_SELECTOR),
   );
+
+// `userEvent.keyboard` is given one string naming every key to press, in which
+// a name of more than one character is wrapped in braces (`{Escape}`) and a
+// single character stands for itself.
+// See: https://vitest.dev/guide/browser/interactivity-api.html#userevent-keyboard
+const asKeyboardInput = (key: string): string => (key.length === 1 ? key : `{${key}}`);
+
+export const pressKey = async (key: string): Promise<void> =>
+  await userEvent.keyboard(asKeyboardInput(key));
+
+export const holdKey = async (key: string): Promise<void> =>
+  await userEvent.keyboard(`{${key}>}`);
+
+export const releaseKey = async (key: string): Promise<void> =>
+  await userEvent.keyboard(`{/${key}}`);
+
+export const pressTab = async (): Promise<void> => await userEvent.tab();
+
+/**
+ * Click an element with a real pointer, which is the only kind that carries the
+ * browser's own behaviour: the press moves focus, and an element that stops the
+ * press doing so leaves it where it was.
+ */
+export const clickElement = async (element: Element): Promise<void> =>
+  await userEvent.click(element);
+
+/**
+ * Send a `pointerdown` to an element without moving a real pointer, so the page
+ * stays scrolled where the test left it: `clickElement` scrolls its target into
+ * view before pressing it.
+ *
+ * The browser does nothing of its own with a press it did not itself deliver,
+ * so what follows is only what the card's own listener does.
+ */
+export const dispatchPointerDown = (element: Element): void => {
+  element.dispatchEvent(
+    new PointerEvent('pointerdown', { bubbles: true, composed: true }),
+  );
+};
+
+/**
+ * The element that actually has focus. `document.activeElement` names the
+ * outermost shadow host in the way, since focus is reported per tree.
+ */
+export const getFocusedElement = (): Element | null => {
+  let focused = document.activeElement;
+  while (focused?.shadowRoot?.activeElement) {
+    focused = focused.shadowRoot.activeElement;
+  }
+  return focused;
+};

tests/card-controller/card-element-manager.browser.test.ts

@@ -0,0 +1,115 @@
+import { describe, expect, it, onTestFinished } from 'vitest';
+
+import { createLogAction } from '../../src/utils/action';
+import { MountedCard } from '../browser/mounted-card';
+import {
+  CARD_INITIALIZED_MESSAGE,
+  createInitializedAutomation,
+  createStillCameraHASS,
+  createStillImageCardConfig,
+  deepQueryAll,
+  getFocusedElement,
+  pressKey,
+  pressTab,
+} from '../browser/test-utils';
+
+// What the automation writes when it runs, written as the pattern the console
+// is later searched for.
+const KEY_MESSAGE = /key pressed/;
+
+const mountCard = async (): Promise<MountedCard> => {
+  const card = await MountedCard.create(
+    createStillImageCardConfig({
+      automations: [
+        createInitializedAutomation(),
+        {
+          triggers: [{ trigger: 'key', key: 'z' }],
+          actions: [createLogAction(KEY_MESSAGE.source)],
+        },
+      ],
+    }),
+    createStillCameraHASS(),
+  );
+
+  await card.events.waitForFirst('advanced-camera-card:media:loaded');
+
+  return card;
+};
+
+/**
+ * Tab until focus is past the card, however many places within it can take
+ * focus. The bound is a runaway guard rather than a count, so that a card
+ * which never lets focus go fails instead of tabbing forever; it is taken from
+ * the card's own size, since nothing in it can be a tab stop twice.
+ */
+const tabPastCard = async (card: MountedCard): Promise<void> => {
+  const bound = deepQueryAll(card.card, '*').length;
+
+  // Tabbing starts from the top of the page, so the first press is the one
+  // that reaches the card.
+  await pressTab();
+
+  for (
+    let press = 0;
+    press < bound && card.card.contains(document.activeElement);
+    press++
+  ) {
+    await pressTab();
+  }
+};
+
+/**
+ * Something to tab on to after the card, standing in for whatever else is on
+ * the dashboard below it.
+ */
+const addTrailingControl = (): HTMLElement => {
+  const control = document.createElement('button');
+  document.body.append(control);
+
+  onTestFinished(() => control.remove());
+
+  return control;
+};
+
+describe('CardElementManager', () => {
+  it('should be reachable by tabbing', async () => {
+    const card = await mountCard();
+
+    // No pointer is used here at all. A card that can only be reached by
+    // clicking on it is out of reach of a keyboard-only user.
+    await pressTab();
+
+    expect(getFocusedElement()).toBe(card.card);
+
+    await pressKey('z');
+    await card.console.waitForMessage(KEY_MESSAGE);
+  });
+
+  it('should be possible to tab beyond the card', async () => {
+    const card = await mountCard();
+    const trailingControl = addTrailingControl();
+
+    await tabPastCard(card);
+
+    // Tabbing continues past the card and out the other side. A card that kept
+    // focus would strand a user part way down the dashboard.
+    expect(getFocusedElement()).toBe(trailingControl);
+  });
+
+  it('should be reachable by tabbing after being put back in the document', async () => {
+    const card = await mountCard();
+
+    // Home Assistant takes a card out of the document when the dashboard tab it
+    // is on is left, and puts the same element back on return.
+    card.detach();
+    card.attach();
+    await card.console.waitForMessage(CARD_INITIALIZED_MESSAGE, { count: 2 });
+
+    await pressTab();
+
+    expect(getFocusedElement()).toBe(card.card);
+
+    await pressKey('z');
+    await card.console.waitForMessage(KEY_MESSAGE);
+  });
+});

tests/card-controller/initialization/session-manager.browser.test.ts

@@ -3,31 +3,21 @@ import { describe, expect, it, vi } from 'vitest';
 import type { RawAdvancedCameraCardConfig } from '../../../src/config/types';
 import { MountedCard } from '../../browser/mounted-card';
 import {
+  CARD_INITIALIZED_MESSAGE,
+  createInitializedAutomation,
   createStillCameraHASS,
   createStillImageCameraConfig,
   createStillImageCardConfig,
   isMediaLoadedInfoEventDetail,
 } from '../../browser/test-utils';
 
-const STARTED_MESSAGE = 'card-started';
 const OTHER_CAMERA_ENTITY = 'camera.other';
 
 const createConfig = (
   overrides?: Partial<RawAdvancedCameraCardConfig>,
 ): RawAdvancedCameraCardConfig =>
   createStillImageCardConfig({
-    automations: [
+    automations: [createInitializedAutomation()],
-      {
-        triggers: [{ trigger: 'initialized' }],
-        actions: [
-          {
-            action: 'fire-dom-event',
-            advanced_camera_card_action: 'log',
-            message: STARTED_MESSAGE,
-          },
-        ],
-      },
-    ],
     ...overrides,
   });
 
@@ -39,11 +29,6 @@ const mount = async (
     createStillCameraHASS({ cameras: [OTHER_CAMERA_ENTITY] }),
   );
 
-// Only the messages the automation logged, since the card logs other things at
-// the same level.
-const getStartedMessages = (card: MountedCard): string[] =>
-  card.console.getMessages('info').filter((message) => message === STARTED_MESSAGE);
-
 // The cameras the card has actually loaded media for, in order. Media that
 // named no camera is left out, since these are only read to ask which camera
 // the card ended up on.
@@ -59,40 +44,40 @@ describe('SessionManager', () => {
   it('should fire an initialized trigger each time the card starts', async () => {
     const card = await mount();
 
-    await vi.waitFor(() => expect(getStartedMessages(card)).toHaveLength(1));
+    await card.console.waitForMessage(CARD_INITIALIZED_MESSAGE);
 
     // The card leaving the page is a change of the value the trigger watches,
     // and must not fire it.
     card.detach();
     await card.updateComplete;
 
-    expect(getStartedMessages(card)).toHaveLength(1);
+    expect(card.console.countMessages(CARD_INITIALIZED_MESSAGE)).toBe(1);
 
     card.attach();
-    await vi.waitFor(() => expect(getStartedMessages(card)).toHaveLength(2));
+    await card.console.waitForMessage(CARD_INITIALIZED_MESSAGE, { count: 2 });
   });
 
   it('should start the card again once Home Assistant comes back', async () => {
     const card = await mount();
 
-    await vi.waitFor(() => expect(getStartedMessages(card)).toHaveLength(1));
+    await card.console.waitForMessage(CARD_INITIALIZED_MESSAGE);
 
     // Losing Home Assistant changes the value the trigger watches, and must not
     // fire it.
     card.setConnected(false);
     await card.updateComplete;
 
-    expect(getStartedMessages(card)).toHaveLength(1);
+    expect(card.console.countMessages(CARD_INITIALIZED_MESSAGE)).toBe(1);
 
     card.setConnected(true);
-    await vi.waitFor(() => expect(getStartedMessages(card)).toHaveLength(2));
+    await card.console.waitForMessage(CARD_INITIALIZED_MESSAGE, { count: 2 });
   });
 
   it('should initialize the new cameras without starting the card again', async () => {
     const card = await mount();
 
     await card.events.waitForFirst('advanced-camera-card:media:loaded');
-    await vi.waitFor(() => expect(getStartedMessages(card)).toHaveLength(1));
+    await card.console.waitForMessage(CARD_INITIALIZED_MESSAGE);
 
     // A camera change is the heaviest configuration change there is: the
     // cameras are destroyed and initialized again.
@@ -107,7 +92,7 @@ describe('SessionManager', () => {
       expect(getLoadedCameraIDs(card)).toContain(OTHER_CAMERA_ENTITY),
     );
 
-    expect(getStartedMessages(card)).toHaveLength(1);
+    expect(card.console.countMessages(CARD_INITIALIZED_MESSAGE)).toBe(1);
   });
 
   it('should apply an override keyed on the card being started every time it starts', async () => {
@@ -127,7 +112,7 @@ describe('SessionManager', () => {
 
     card.detach();
     card.attach();
-    await vi.waitFor(() => expect(getStartedMessages(card)).toHaveLength(2));
+    await card.console.waitForMessage(CARD_INITIALIZED_MESSAGE, { count: 2 });
 
     await card.waitForSelector('advanced-camera-card-menu');
   });
@@ -142,7 +127,7 @@ describe('SessionManager', () => {
 
     card.detach();
     card.attach();
-    await vi.waitFor(() => expect(getStartedMessages(card)).toHaveLength(2));
+    await card.console.waitForMessage(CARD_INITIALIZED_MESSAGE, { count: 2 });
 
     // A card that has been on screen once must not show the loading indicator
     // again when it is re-attached.

tests/card-controller/issues/issues/initialization.browser.test.ts

@@ -2,22 +2,20 @@ import { describe, expect, it, vi } from 'vitest';
 
 import { MountedCard } from '../../../browser/mounted-card';
 import {
+  CARD_INITIALIZED_MESSAGE,
+  createInitializedAutomation,
   createStillCameraHASS,
   createStillImageCameraConfig,
   createStillImageCardConfig,
   getBlockNotificationText,
 } from '../../../browser/test-utils';
 
-const STARTED_MESSAGE = 'card-started';
 const INIT_FAILED_ISSUE_HEADING = 'Initialization failed';
 
 // A camera Home Assistant has never heard of, which is what a typo in a
 // configuration looks like and the earliest thing a camera can fail on.
 const MISSING_CAMERA_ENTITY = 'camera.missing';
 
-const getStartedMessages = (card: MountedCard): string[] =>
-  card.console.getMessages('info').filter((message) => message === STARTED_MESSAGE);
-
 const getReportedInitializationFailures = (card: MountedCard): string[] =>
   card.console
     .getMessages('warn')
@@ -40,18 +38,7 @@ const mountBrokenCard = async (): Promise<MountedCard> =>
       // Automatic retries switched off, so any recovery below can only be the
       // retry control being used.
       view: { issues: { retry_seconds: 0 } },
-      automations: [
+      automations: [createInitializedAutomation()],
-        {
-          triggers: [{ trigger: 'initialized' }],
-          actions: [
-            {
-              action: 'fire-dom-event',
-              advanced_camera_card_action: 'log',
-              message: STARTED_MESSAGE,
-            },
-          ],
-        },
-      ],
     }),
     createStillCameraHASS(),
   );
@@ -63,7 +50,7 @@ describe('InitializationIssue', () => {
     await waitForInitializationFailures(card);
 
     // A card that failed to start has not started, whatever it is showing.
-    expect(getStartedMessages(card)).toHaveLength(0);
+    expect(card.console.countMessages(CARD_INITIALIZED_MESSAGE)).toBe(0);
 
     // The camera the user meant now exists. Nothing recovers on its own from
     // here: automatic retries are off, and a card showing a full-card issue
@@ -71,7 +58,7 @@ describe('InitializationIssue', () => {
     card.setEntityState(MISSING_CAMERA_ENTITY, 'idle');
     await card.clickControl('Retry');
 
-    await vi.waitFor(() => expect(getStartedMessages(card)).toHaveLength(1));
+    await card.console.waitForMessage(CARD_INITIALIZED_MESSAGE);
     await card.events.waitForFirst('advanced-camera-card:media:loaded');
 
     // Starting is not the same as the issue leaving the screen, since a
@@ -95,6 +82,6 @@ describe('InitializationIssue', () => {
     );
     await waitForInitializationFailures(card);
 
-    expect(getStartedMessages(card)).toHaveLength(0);
+    expect(card.console.countMessages(CARD_INITIALIZED_MESSAGE)).toBe(0);
   });
 });

tests/card-controller/keyboard-state-manager.browser.test.ts

@@ -0,0 +1,323 @@
+import { assert, describe, expect, it } from 'vitest';
+
+import type { LogActionConfig } from '../../src/config/schema/actions/custom/log';
+import { createLogAction } from '../../src/utils/action';
+import { MountedCard, type MountOptions } from '../browser/mounted-card';
+import {
+  CARD_INITIALIZED_MESSAGE,
+  clickElement,
+  createInitializedAutomation,
+  createStillCameraHASS,
+  createStillImageCardConfig,
+  dispatchPointerDown,
+  getFocusedElement,
+  holdKey,
+  pressKey,
+  releaseKey,
+} from '../browser/test-utils';
+
+const ZOOM_ENTITY = 'input_boolean.zoom';
+
+// What each automation writes when it runs, written as the pattern the console
+// is later searched for. The console is the only place a `log` action reports
+// to, and a message that names the automation is what makes one key press
+// distinguishable from another.
+const KEY_MESSAGE = /plain key press/;
+const OTHER_CARD_KEY_MESSAGE = /key press on the other card/;
+const CTRL_KEY_MESSAGE = /key press with ctrl held/;
+const KEY_DOWN_MESSAGE = /key on the way down/;
+const KEY_UP_MESSAGE = /key on the way up/;
+const MENU_BUTTON_MESSAGE = /menu button pressed/;
+
+const MENU_BUTTON_CONTROL = 'Log';
+const EXPAND_CONTROL = 'Expand';
+
+// The card's own builder, given the text its pattern matches.
+const logAction = (regexp: RegExp): LogActionConfig => createLogAction(regexp.source);
+
+interface MountCardOptions extends MountOptions {
+  // What a plain key press logs, so that a test with two cards on the page can
+  // tell which of them answered.
+  keyMessage?: RegExp;
+}
+
+const mountCard = async (options?: MountCardOptions): Promise<MountedCard> => {
+  const { keyMessage, ...mountOptions } = options ?? {};
+
+  const card = await MountedCard.create(
+    createStillImageCardConfig({
+      menu: { style: 'outside', buttons: { expand: { enabled: true } } },
+      elements: [
+        {
+          type: 'custom:advanced-camera-card-menu-icon',
+          icon: 'mdi:cow',
+          title: MENU_BUTTON_CONTROL,
+          tap_action: logAction(MENU_BUTTON_MESSAGE),
+        },
+      ],
+      automations: [
+        createInitializedAutomation(),
+        {
+          triggers: [{ trigger: 'key', key: 'z' }],
+          actions: [logAction(keyMessage ?? KEY_MESSAGE)],
+        },
+        {
+          triggers: [{ trigger: 'key', key: 'b', ctrl: true }],
+          actions: [logAction(CTRL_KEY_MESSAGE)],
+        },
+        {
+          triggers: [{ trigger: 'key', key: 'w', state: 'down' }],
+          actions: [logAction(KEY_DOWN_MESSAGE)],
+        },
+        {
+          triggers: [{ trigger: 'key', key: 'w', state: 'up' }],
+          actions: [logAction(KEY_UP_MESSAGE)],
+        },
+        // A key whose action redraws the card, so a test can press a key, have
+        // the picture replaced under it, and press again.
+        {
+          triggers: [{ trigger: 'key', key: '1' }],
+          actions: [
+            {
+              action: 'fire-dom-event',
+              advanced_camera_card_action: 'ptz_digital',
+              absolute: { zoom: 3 },
+            },
+          ],
+        },
+
+        // The same zoom driven by an entity rather than a key, so a test can
+        // zoom the card without pressing or clicking it first. A zoomed
+        // picture takes a press as the start of a pan, which is what such a
+        // test is about.
+        {
+          triggers: [{ trigger: 'state', entity: ZOOM_ENTITY, to: 'on' }],
+          actions: [
+            {
+              action: 'fire-dom-event',
+              advanced_camera_card_action: 'ptz_digital',
+              absolute: { zoom: 3 },
+            },
+          ],
+        },
+      ],
+    }),
+    createStillCameraHASS({ entities: { [ZOOM_ENTITY]: 'off' } }),
+    mountOptions,
+  );
+
+  await card.events.waitForFirst('advanced-camera-card:media:loaded');
+
+  return card;
+};
+
+// What the live view draws the camera into, which is the part of the card a
+// user looks at and the largest part of it that is not a control.
+const LIVE_MEDIA_SELECTOR = 'advanced-camera-card-live-provider';
+
+const clickMedia = async (card: MountedCard): Promise<void> =>
+  await clickElement(await card.waitForSelector(LIVE_MEDIA_SELECTOR));
+
+describe('KeyboardStateManager', () => {
+  it('should not act on a key until the card has been used', async () => {
+    const card = await mountCard();
+
+    // A key press belongs to whatever the user is looking at. A card that
+    // answered one aimed at something else on the dashboard would fire
+    // shortcuts nobody asked for.
+    await pressKey('z');
+
+    await clickMedia(card);
+    await pressKey('z');
+    await card.console.waitForMessage(KEY_MESSAGE);
+
+    // Once, from the press after the card was used. The first press is what
+    // this test is about, and only counting says it was ignored rather than
+    // merely slow.
+    expect(card.console.countMessages(KEY_MESSAGE)).toBe(1);
+  });
+
+  it('should keep receiving keys after an action has redrawn the card', async () => {
+    const card = await mountCard();
+
+    await clickMedia(card);
+
+    // The zoom replaces what is on screen, and the card is drawn again around
+    // it. Anything holding focus below the card would be thrown away here.
+    await pressKey('1');
+    await card.events.waitForFirst('advanced-camera-card:zoom:zoomed');
+
+    await pressKey('z');
+    await card.console.waitForMessage(KEY_MESSAGE);
+  });
+
+  it('should keep receiving keys after a menu button has been pressed', async () => {
+    const card = await mountCard();
+
+    await card.clickControl(MENU_BUTTON_CONTROL);
+
+    // The button did what it was asked, so nothing about claiming focus
+    // swallowed the press on its way in.
+    await card.console.waitForMessage(MENU_BUTTON_MESSAGE);
+
+    await pressKey('z');
+    await card.console.waitForMessage(KEY_MESSAGE);
+  });
+
+  it('should claim focus from a press that is consumed by the card', async () => {
+    const card = await mountCard();
+
+    card.setEntityState(ZOOM_ENTITY, 'on');
+    await card.events.waitForFirst('advanced-camera-card:zoom:zoomed');
+
+    // A press on a zoomed picture is taken as the start of a pan: it is kept
+    // from reaching anything else, and the browser is told not to do what it
+    // would normally do with it, which includes moving focus.
+    await clickMedia(card);
+
+    expect(getFocusedElement()).toBe(card.card);
+
+    await pressKey('z');
+    await card.console.waitForMessage(KEY_MESSAGE);
+  });
+
+  it('should not scroll the page when it takes focus', async () => {
+    // Well below the window, so the card is out of sight until the page is
+    // scrolled to it.
+    const card = await mountCard({ position: { top: '2000px' } });
+
+    window.scrollTo(0, 0);
+
+    // Pressed without a pointer: a real one is moved to what it presses, and
+    // where the page ends up is the thing being asserted on here.
+    dispatchPointerDown(await card.waitForSelector(LIVE_MEDIA_SELECTOR));
+
+    // The card is far below what is on screen. A user pressing a card they can
+    // only see part of would find the dashboard jumping under them.
+    expect(window.scrollY).toBe(0);
+
+    expect(getFocusedElement()).toBe(card.card);
+  });
+
+  it('should leave focus where it is when it is already inside the card', async () => {
+    const card = await mountCard();
+
+    await card.clickControl(MENU_BUTTON_CONTROL);
+    await card.console.waitForMessage(MENU_BUTTON_MESSAGE);
+
+    // Pressing a control puts focus on it rather than on the card around it,
+    // which is the situation this test is about.
+    const control = getFocusedElement();
+    assert(control);
+    expect(control).not.toBe(card.card);
+
+    let lostFocus = false;
+    control.addEventListener('focusout', () => (lostFocus = true));
+
+    await card.clickControl(MENU_BUTTON_CONTROL);
+    await card.console.waitForMessage(MENU_BUTTON_MESSAGE, { count: 2 });
+
+    // Taking focus off a control the user is working in is how a field being
+    // typed into loses what is in it, or a picker closes mid-choice.
+    expect(lostFocus).toBe(false);
+    expect(getFocusedElement()).toBe(control);
+  });
+
+  it('should hold on to a held key while a control in the card is pressed', async () => {
+    const card = await mountCard();
+
+    await clickMedia(card);
+
+    await holdKey('w');
+    await card.console.waitForMessage(KEY_DOWN_MESSAGE);
+
+    // Focus moves from the card to the button within it, which is not the user
+    // letting go of the key.
+    await card.clickControl(MENU_BUTTON_CONTROL);
+    await card.console.waitForMessage(MENU_BUTTON_MESSAGE);
+
+    // A key whose press was forgotten has no release either, which is what
+    // leaves a camera panning with nothing to stop it.
+    await releaseKey('w');
+    await card.console.waitForMessage(KEY_UP_MESSAGE);
+  });
+
+  it('should act on a key only when its modifiers match', async () => {
+    const card = await mountCard();
+
+    await clickMedia(card);
+
+    await pressKey('b');
+
+    // The trigger calls the modifier `ctrl`; the keyboard calls the key
+    // `Control`.
+    await holdKey('Control');
+    await pressKey('b');
+    await releaseKey('Control');
+    await card.console.waitForMessage(CTRL_KEY_MESSAGE);
+
+    // The press without the modifier is a different shortcut, and one this card
+    // has nothing configured for.
+    expect(card.console.countMessages(CTRL_KEY_MESSAGE)).toBe(1);
+  });
+
+  it('should keep receiving keys while expanded', async () => {
+    const card = await mountCard();
+
+    await card.clickControl(EXPAND_CONTROL);
+
+    // The whole card is drawn again inside a dialog, which is as large a
+    // change as anything that happens to it.
+    await card.waitForSelector('web-dialog');
+
+    await clickMedia(card);
+    await pressKey('z');
+    await card.console.waitForMessage(KEY_MESSAGE);
+  });
+
+  it('should stop receiving keys once it is taken out of the document', async () => {
+    const card = await mountCard();
+
+    await clickMedia(card);
+    await pressKey('z');
+    await card.console.waitForMessage(KEY_MESSAGE);
+
+    card.detach();
+
+    // A card on a dashboard tab that is not being looked at is out of the
+    // document, and answering keys from there would run shortcuts on a card
+    // nobody can see.
+    await pressKey('z');
+    expect(card.console.countMessages(KEY_MESSAGE)).toBe(1);
+
+    card.attach();
+
+    // The card builds itself again from nothing on its return, and answers
+    // nothing until it has.
+    await card.console.waitForMessage(CARD_INITIALIZED_MESSAGE, { count: 2 });
+
+    await clickMedia(card);
+    await pressKey('z');
+    await card.console.waitForMessage(KEY_MESSAGE, { count: 2 });
+  });
+
+  it('should not act on a key aimed at another card', async () => {
+    const card = await mountCard();
+    const otherCard = await mountCard({ keyMessage: OTHER_CARD_KEY_MESSAGE });
+
+    // Either ledger reports both cards, since there is only one console. Which
+    // card answered is in the message rather than in where it was read.
+    await clickMedia(card);
+    await pressKey('z');
+    await card.console.waitForMessage(KEY_MESSAGE);
+
+    await clickMedia(otherCard);
+    await pressKey('z');
+    await card.console.waitForMessage(OTHER_CARD_KEY_MESSAGE);
+
+    // One press each. A dashboard of cards that all answer every key press
+    // would run a shortcut once per card on screen.
+    expect(card.console.countMessages(KEY_MESSAGE)).toBe(1);
+    expect(card.console.countMessages(OTHER_CARD_KEY_MESSAGE)).toBe(1);
+  });
+});