testdriverai/testdriver:assert
Make AI-powered assertions about screen state
npx skills add https://github.com/testdriverai/testdriverai --skill testdriver:assert
<!-- Generated from assert.mdx. DO NOT EDIT. -->
Make AI-powered assertions about the current screen state using natural language. The AI analyzes the screen and verifies that your assertion is true.
await testdriver.assert(assertion)
await testdriver.assert(assertion, options)
<ParamField path="assertion" type="string" required>
Natural language description of what should be true
</ParamField>
<ParamField path="options" type="object">
Optional configuration
<Expandable title="properties">
<ParamField path="ai" type="object">
AI sampling configuration for this assert call (overrides global ai config from constructor).
<Expandable title="properties">
<ParamField path="temperature" type="number">
Controls randomness. 0 = deterministic, higher = more creative. Default: model default.
</ParamField>
<ParamField path="top" type="object">
Sampling parameters
<Expandable title="properties">
<ParamField path="p" type="number">
Top-P (nucleus sampling). Range: 0-1.
</ParamField>
<ParamField path="k" type="number">
Top-K sampling. 1 = most deterministic.
</ParamField>
</Expandable>
</ParamField>
</Expandable>
</ParamField>
</Expandable>
</ParamField>
Promise<boolean> - true if assertion passes, throws error if assertion fails
// Verify page elements
await testdriver.assert('the login page is displayed');
await testdriver.assert('submit button is visible');
await testdriver.assert('error message is shown');
// Verify text content
await testdriver.assert('the page title is "Welcome"');
await testdriver.assert('username field contains "john.doe"');
await testdriver.assert('success message says "Account created"');
// Verify states
await testdriver.assert('the form is empty');
await testdriver.assert('the checkbox is checked');
await testdriver.assert('the dropdown shows "United States"');
// Verify visual appearance
await testdriver.assert('the button is blue');
await testdriver.assert('the loading spinner is displayed');
await testdriver.assert('the modal dialog is open');
<Check>
Be specific in assertions
More specific assertions are more reliable:
// ❌ Too vague
await testdriver.assert('button is visible');
// ✅ Specific
await testdriver.assert('blue submit button is visible below the form');
</Check>
<Check>
Assert state changes
Verify state before and after actions:
// Before
await testdriver.assert('cart is empty');
// Action
const addBtn = await testdriver.find('add to cart');
await addBtn.click();
// After
await testdriver.assert('cart contains 1 item');
</Check>
<Check>
Use with test framework assertions
Combine AI assertions with traditional test assertions:
// AI assertion
const result = await testdriver.assert('success message is displayed');
// Framework assertion
expect(result).toBeTruthy();
// Extract for detailed comparison
const message = await testdriver.extract('the success message text');
expect(message).toContain('successfully');
</Check>
For conditions that may take time to become true:
async function waitForAssertion(testdriver, assertion, timeout = 30000) {
const startTime = Date.now();
while (Date.now() - startTime < timeout) {
try {
await testdriver.assert(assertion);
return true; // Assertion passed
} catch (error) {
// Assertion failed, wait and retry
await new Promise(r => setTimeout(r, 1000));
}
}
throw new Error(`Assertion timeout: "${assertion}"`);
}
// Usage
await waitForAssertion(testdriver, 'page has finished loading', 30000);
await waitForAssertion(testdriver, 'results are displayed', 10000);
<AccordionGroup>
<Accordion title="Form Validation">
// Try to submit empty form
const submitBtn = await testdriver.find('submit button');
await submitBtn.click();
// Verify validation errors
await testdriver.assert('email field shows "required" error');
await testdriver.assert('password field shows "required" error');
// Verify form not submitted
await testdriver.assert('still on the form page');
</Accordion>
<Accordion title="Page Navigation">
const loginBtn = await testdriver.find('login button');
await loginBtn.click();
// Verify navigation
await testdriver.assert('user dashboard is displayed');
await testdriver.assert('welcome message shows user name');
await testdriver.assert('logout button is visible');
</Accordion>
<Accordion title="Dynamic Content">
const loadBtn = await testdriver.find('load more button');
await loadBtn.click();
// Poll for content using helper
await waitForAssertion(testdriver, 'more than 10 items are shown', 10000);
await testdriver.assert('load more button is still visible');
</Accordion>
<Accordion title="Visual States">
// Verify hover effect
const button = await testdriver.find('primary button');
await button.hover();
await testdriver.assert('button background is darker');
// Verify button is enabled
await testdriver.assert('submit button is enabled');
</Accordion>
<Accordion title="Multi-Step Workflows">
// Step 1
await testdriver.assert('step 1 is active');
const nextBtn = await testdriver.find('next button');
await nextBtn.click();
// Step 2
await testdriver.assert('step 2 is active');
await testdriver.assert('step 1 is completed');
await nextBtn.click();
// Step 3
await testdriver.assert('step 3 is active');
await testdriver.assert('step 2 is completed');
</Accordion>
</AccordionGroup>
import { beforeAll, afterAll, describe, it, expect } from 'vitest';
import TestDriver from 'testdriverai';
describe('Assertions', () => {
let testdriver;
beforeAll(async () => {
client = new TestDriver(process.env.TD_API_KEY);
await testdriver.auth();
await testdriver.connect();
});
afterAll(async () => {
await testdriver.disconnect();
});
it('should validate login flow', async () => {
await testdriver.focusApplication('Google Chrome');
// Verify initial state
await testdriver.assert('the login page is displayed');
await testdriver.assert('username field is empty');
await testdriver.assert('password field is empty');
// Fill form
const usernameField = await testdriver.find('username input');
await usernameField.click();
await testdriver.type('testuser');
await testdriver.pressKeys(['tab']);
await testdriver.type('password123');
// Verify fields filled
await testdriver.assert('username field contains "testuser"');
await testdriver.assert('password field is not empty');
// Submit
await testdriver.pressKeys(['enter']);
// Poll for success
await waitForAssertion(testdriver, 'user dashboard is displayed', 10000);
// Verify logged in state
await testdriver.assert('welcome message is shown');
await testdriver.assert('logout button is visible');
// Verify login page is gone
await testdriver.assert('login form is displayed', false, true);
});
it('should show validation errors', async () => {
// Try empty submission
const submitBtn = await testdriver.find('submit button');
await submitBtn.click();
// Verify multiple errors
const errors = [
'email field shows error',
'name field shows error',
'password field shows error'
];
for (const error of errors) {
const result = await testdriver.assert(error);
expect(result).toBeTruthy();
}
// Verify not submitted
await testdriver.assert('confirmation page is shown', false, true);
});
});
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