karibu-test

name	karibu-test
description	Creates Karibu server-side unit tests for Vaadin views covering navigation, component interactions, form validation, grid operations, and notifications. Use when the user asks to "write Karibu tests", "unit test a Vaadin view", "test the UI server-side", "create view tests", or mentions Karibu testing, Vaadin unit tests, or server-side UI testing.

Karibu Test

Instructions

Create Karibu unit tests for Vaadin views based on the use case $ARGUMENTS. Karibu Testing allows server-side testing of Vaadin components without a browser.

Use the KaribuTesting MCP server for documentation and code generation.

DO NOT

• Use Mockito for mocking
• Use @Transactional annotation (transaction boundaries must stay intact)
• Use services, repositories, or DSLContext to create test data
• Delete all data in cleanup (only remove data created during the test)
• Use browser-based testing patterns (this is server-side testing)

Test Data Strategy

Create test data using Flyway migrations in src/test/resources/db/migration.

Approach	Location	Purpose
Flyway migration	src/test/resources/db/migration/V*.sql	Populate test data
Manual cleanup	@AfterEach method	Remove test-created data

Key Helper Classes

Class	Purpose
com.github.mvysny.kaributesting.v10.LocatorJ	Find components
com.github.mvysny.kaributesting.v10.GridKt	Grid assertions and interactions
com.github.mvysny.kaributesting.v10.NotificationsKt	Notification assertions
com.github.mvysny.kaributesting.v10.pro.ConfirmDialogKt	ConfirmDialog interactions

Template

Use templates/ExampleViewTest.java as the test class structure.

Common Patterns

Navigate to View

UI.getCurrent().navigate(PersonView.class);

Find Components

// Find by type
var grid = _get(Grid.class);
var button = _get(Button.class, spec -> spec.withCaption("Save"));
var textField = _get(TextField.class, spec -> spec.withLabel("Name"));

// Find all matching
List<Button> buttons = _find(Button.class);

Grid Operations

// Get grid size
assertThat(GridKt._size(grid)).isEqualTo(100);

// Get selected items
Set<PersonRecord> selected = grid.getSelectedItems();

// Select a row
GridKt._selectRow(grid, 0);

// Get cell component (for action buttons)
GridKt._getCellComponent(grid, 0, "actions")
    .getChildren()
    .filter(Button.class::isInstance)
    .findFirst()
    .map(Button.class::cast)
    .ifPresent(Button::click);

// Get cell value
String name = GridKt._getFormattedRow(grid, 0).get("name");

Form Interactions

// Set field values
_get(TextField.class, spec -> spec.withLabel("Name"))._setValue("John");
_get(ComboBox.class, spec -> spec.withLabel("Country"))._setValue(country);
_get(DatePicker.class, spec -> spec.withLabel("Birth Date"))._setValue(LocalDate.of(1990, 1, 1));

// Click button
_get(Button.class, spec -> spec.withCaption("Save"))._click();

Notification Assertions

// Expect notification
expectNotifications("Record saved successfully");

// Assert no notifications
assertThat(NotificationsKt.getNotifications()).isEmpty();

ConfirmDialog

// Click confirm in dialog
ConfirmDialogKt._fireConfirm(_get(ConfirmDialog.class));

// Click cancel
ConfirmDialogKt._fireCancel(_get(ConfirmDialog.class));

Assertions Reference

Use AssertJ or Karibu Testing assertions:

Assertion Type	Example
Grid size	assertThat(GridKt._size(grid)).isEqualTo(10)
Component visible	assertThat(button.isVisible()).isTrue()
Component enabled	assertThat(button.isEnabled()).isTrue()
Field value	assertThat(textField.getValue()).isEqualTo("x")
Collection size	assertThat(items).hasSize(5)
Notifications	expectNotifications("Success")

Workflow

1. Read the use case specification
2. Use TodoWrite to create a task for each test scenario
3. Create test class using the template
4. For each test:
   • Navigate to the view
   • Find components using LocatorJ
   • Perform interactions
   • Assert expected outcomes
   • Clean up test data if created during test
5. Run tests to verify they pass
6. If a test fails:
   • Check component locators with _dump() to inspect the component tree
   • Verify test data exists in the Flyway test migrations
   • Ensure navigation to the correct view before finding components
7. Mark todos complete

Resources

• Karibu Testing documentation: https://github.com/mvysny/karibu-testing/tree/master/karibu-testing-v10
• Use the KaribuTesting MCP server for additional patterns