feat: Add support for templates in actions (#1891)

- Closes #1878

tests/templates/index.test.ts

@@ -0,0 +1,93 @@
+import { renderTemplate } from 'ha-nunjucks';
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { TemplateRenderer } from '../../src/card-controller/templates';
+import { ConditionsEvaluationData, ConditionState } from '../../src/conditions/types';
+import { createHASS } from '../test-utils';
+
+// ha-nunjucks attempts to make websocket calls initially so mock it out.
+vi.mock('ha-nunjucks');
+
+describe('TemplateRenderer', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it('should render data', () => {
+    const data = {
+      camera: '{{ acc.camera }}',
+      array: ['{{ acc.camera }}', '{{ acc.view }}'],
+      nested: {
+        camera: '{{ acc.camera }}',
+      },
+      number: 42,
+    };
+
+    vi.mocked(renderTemplate)
+      .mockReturnValueOnce('one')
+      .mockReturnValueOnce('two')
+      .mockReturnValueOnce('three')
+      .mockReturnValueOnce('four');
+
+    const renderer = new TemplateRenderer();
+    const hass = createHASS();
+
+    expect(renderer.renderRecursively(hass, data)).toEqual({
+      camera: 'one',
+      array: ['two', 'three'],
+      nested: {
+        camera: 'four',
+      },
+      number: 42,
+    });
+  });
+
+  it('should include triggers', () => {
+    const conditionState: ConditionState = {
+      camera: 'camera',
+      view: 'view',
+    };
+    const triggerData: ConditionsEvaluationData = {
+      camera: {
+        to: 'camera',
+        from: 'previous-camera',
+      },
+    };
+
+    const renderer = new TemplateRenderer();
+    const hass = createHASS();
+
+    renderer.renderRecursively(
+      hass,
+      {
+        key: 'value',
+      },
+      {
+        conditionState,
+        triggerData,
+      },
+    );
+
+    expect(renderTemplate).toHaveBeenCalledWith(hass, 'value', {
+      acc: {
+        camera: 'camera',
+        view: 'view',
+        trigger: {
+          camera: {
+            to: 'camera',
+            from: 'previous-camera',
+          },
+        },
+      },
+      advanced_camera_card: {
+        camera: 'camera',
+        view: 'view',
+        trigger: {
+          camera: {
+            to: 'camera',
+            from: 'previous-camera',
+          },
+        },
+      },
+    });
+  });
+});