Your First Test

Quick start with init

The fastest way to get started is using vanya init:

# Create a browser test template
vanya init todo_app.vanya --template browser

# Or create an API test template
vanya init api_test.vanya --template api

This generates a working example file you can modify for your tests. Or create one manually:

Create a test file

Create a file called todo_app.vanya:

Vanya test scenario (vanya-lang.org/v0.1)

Script title: "todo_app"

Setup for each Scenario:
    Within the Browser (plugin: playwright-python, type: browser)
        go to "https://demo.playwright.dev/todomvc/"
        Define new-todo (class: 'new-todo')

Scenario: "user can add a todo"
    type "Learn Vanya" into new-todo
    press Enter
    see a li (text: 'Learn Vanya')

Scenario: "user can add multiple todos"
    type "First task" into new-todo
    press Enter
    type "Second task" into new-todo
    press Enter
    see a li (text: 'First task')
    see a li (text: 'Second task')

Define vs Within

Use Define to create a named alias for an element you’ll interact with directly. Use Within when you need to scope multiple actions to a container element. On TodoMVC, the .new-todo class IS the input element itself, so we use Define rather than Within.

Backward compatibility

Single-scenario syntax (without Scenario: blocks) is still supported. Files without explicit scenarios are treated as a single test. Multi-scenario syntax is recommended for better test organization and isolation.

Check the syntax

Run the checker to validate your test:

vanya check todo_app.vanya

If everything is correct, you’ll see:

todo_app.vanya: OK

Build the test

Transpile to Python:

vanya build todo_app.vanya -o out/ --format pytest-function

This creates out/test_todo_app.py (and out/test_todo_app.py.vanyamap for source mapping) ready to run with pytest. The --format pytest-function flag wraps your test in a proper def test_...() function and adds the test_ prefix for pytest discovery. Each Scenario: block becomes a separate test function.

Output formats

Format	Description	Use Case
raw	Plain Python code	Custom test runners
pytest-function	Wrapped in def test_...()	pytest integration

Run the generated test

Step 1: Install test dependencies

pip install pytest playwright pytest-playwright

Step 2: Install Chromium system libraries

On Linux and macOS, Chromium requires system libraries (libnspr4, libnss3, etc.). This step is required for the test to run:

# Linux/macOS - installs system dependencies for Chromium
sudo playwright install-deps chromium

Running without sudo

In containers or CI environments where you don’t have sudo access, see the Playwright system requirements for manual package installation. Windows users can skip this step.

Step 3: Download browser binaries

playwright install chromium

Step 4: Run the test

pytest out/test_todo_app.py -v

Expected output:

============================= test session starts ==============================
collected 2 items

out/test_todo_app.py::test_todo_app_user_can_add_a_todo PASSED            [ 50%]
out/test_todo_app.py::test_todo_app_user_can_add_multiple_todos PASSED    [100%]

============================= 2 passed in 4.12s ================================

Next steps

• Learn about Scenarios for organizing multiple test cases
• Learn more about vanya syntax
• Explore available plugins
• Read the CLI reference
• Set up CI/CD integration
• See Recipes for patterns like dynamic IDs, URL assertions, and role-based selectors