Add unit tests for AdminAutoHeightTextInput

client/src/entrypoints/admin/telepath/widgets.js

@@ -92,7 +92,7 @@ window.telepath.register('wagtail.widgets.PageChooser', PageChooser);
 class AdminAutoHeightTextInput extends Widget {
     render(placeholder, name, id, initialState) {
         const boundWidget = super.render(placeholder, name, id, initialState);
-        window.autosize($(id));
+        window.autosize($('#' + id));
         return boundWidget;
     }
 }

client/src/entrypoints/admin/telepath/widgets.test.js

@@ -197,3 +197,52 @@ describe('telepath: wagtail.widgets.PageChooser', () => {
     expect(document.activeElement).toBe(document.querySelector('.unchosen button'));
   });
 });
+
+describe('telepath: wagtail.widgets.AdminAutoHeightTextInput', () => {
+  let boundWidget;
+
+  beforeEach(() => {
+    window.autosize = jest.fn();
+
+    // Create a placeholder to render the widget
+    document.body.innerHTML = '<div id="placeholder"></div>';
+
+    // Unpack and render a textarea using the AdminAutoHeightTextInput widget
+    const widgetDef = window.telepath.unpack({
+      _type: 'wagtail.widgets.AdminAutoHeightTextInput',
+      _args: [
+        '<textarea name="__NAME__" cols="40" rows="1" id="__ID__"></textarea>',
+        '__ID__'
+      ]
+    });
+    boundWidget = widgetDef.render($('#placeholder'), 'the-name', 'the-id', 'The Value');
+  });
+
+  test('it renders correctly', () => {
+    expect(document.body.innerHTML).toBe('<textarea name="the-name" cols="40" rows="1" id="the-id"></textarea>');
+    expect(document.querySelector('textarea').value).toBe('The Value');
+  });
+
+  test('window.autosize was called', () => {
+    expect(window.autosize.mock.calls.length).toBe(1);
+    expect(window.autosize.mock.calls[0][0].get(0)).toBe(document.querySelector('textarea'));
+  });
+
+  test('getValue() returns the current value', () => {
+    expect(boundWidget.getValue()).toBe('The Value');
+  });
+
+  test('getState() returns the current state', () => {
+    expect(boundWidget.getState()).toBe('The Value');
+  });
+
+  test('setState() changes the current state', () => {
+    boundWidget.setState('The new Value');
+    expect(document.querySelector('textarea').value).toBe('The new Value');
+  });
+
+  test('focus() focuses the text input', () => {
+    boundWidget.focus();
+    expect(document.activeElement).toBe(document.querySelector('textarea'));
+  });
+});