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JSON API Examples

In this section, we'll cover some examples of testing JSON APIs using VoltTest PHP SDK.

Ex:

Authentication API Testing​

Authentication is a common use case for APIs. In this example, we'll test an authentication API that requires a login request to get an access token and then use that token in subsequent requests.

$test = new VoltTest('API Authentication Test');
$test->setVirtualUsers(10);

$scenario = $test->scenario('API Authentication');

// Login Request
$scenario->step('Login')
    ->post('https://api.example.com/auth/login', json_encode([
        'email' => 'some@mail.com',
        'password' => 'secret' 
    ]))
    ->header('Content-Type', 'application/json')
    ->validateStatus('login_success', 200)
    ->extractFromJson('access_token', 'data.token');

// Use Token in Subsequent Requests
$scenario->step('Get Profile')
    ->get('https://api.example.com/profile')
    ->header('Authorization', 'Bearer ${access_token}')
    ->validateStatus('profile_success', 200);

// Run the test and get the result
$result = $test->run();

echo $result->getRawOutput();

In the example above, we create a new test named "API Authentication Test" and set the number of virtual users to 10. We then create a scenario named "API Authentication" and add two steps to it. The first step sends a POST request to the login endpoint with the email and password, validates the login success status, and extracts the access token from the JSON response. The second step sends a GET request to the profile endpoint with the access token in the Authorization header and validates the profile success status.

CRUD Operations​

CRUD (Create, Read, Update, Delete) operations are fundamental to APIs. In this example, we'll test a JSON API that supports CRUD operations for managing users.

$test = new VoltTest('CRUD Operations Test');
$test->setVirtualUsers(100);
$test->setDuration('1m');

$scenario = $test->scenario('CRUD Operations');

// Create
$scenario->step('Create User')
    ->post('https://api.example.com/users', json_encode([
        'name' => 'John Doe',
        'email' => 'some@mail.com',
        'role' => 'user',
    ]))
    ->header('Content-Type', 'application/json')
    ->validateStatus('creation_success', 201)
    ->extractFromJson('user_id', 'data.id');

// Read
$scenario->step('Get User')
    ->get('https://api.example.com/users/${user_id}')
    ->validateStatus('read_success', 200);

// Update
$scenario->step('Update User')
    ->put('https://api.example.com/users/${user_id}', json_encode([
        'name' => 'Jane Doe',
        'email' => 'update@mail.com',
    ]))
    ->header('Content-Type', 'application/json')
    ->validateStatus('update_success', 200);

// Delete
$scenario->step('Delete User')
    ->delete('https://api.example.com/users/${user_id}')
    ->validateStatus('delete_success', 204);

// Run the test and get the result
$result = $test->run();

echo $result->getRawOutput();

In the example above, we create a new test named "CRUD Operations Test" and set the number of virtual users to 100 and the test duration to 1 minute. We then create a scenario named "CRUD Operations" and add four steps to it. The first step sends a POST request to create a new user, validates the creation success status, and extracts the user ID from the JSON response. The second step sends a GET request to retrieve the user details. The third step sends a PUT request to update the user details, and the fourth step sends a DELETE request to delete the user.

Data Driven API Testing​

Data-driven testing involves running the same test scenario with different sets of data. In this example, we'll test an API that requires different user data for registration.

$test = new VoltTest('Data-Driven API Test');
$test->setVirtualUsers(50);

// Configure data source
$dataConfig = new DataSourceConfiguration(
    __DIR__ . '/test_users.csv',    // CSV with test data
    'random',            // Random selection
    true                 // Has header row
);

$scenario = $test->scenario('Registration Test')
    ->setDataSourceConfiguration($dataConfig);

// Registration process using data from CSV
$scenario->step('Submit Registration')
    ->post('https://api.example.com/register', json_encode([
        'name' => '${name}',
        'email' => '${email}',
        'phone' => '${phone}',
    ]))
    ->header('Content-Type', 'application/json')
    ->validateStatus('registration_success', 200);

// Run the test and get the result
$result = $test->run();
echo $result->getRawOutput();

In the example above, we create a new test named "Data-Driven API Test" and set the number of virtual users to 50. We then configure a data source using a CSV file with test data and set it to random selection. We create a scenario named "Registration Test" and set the data source configuration. The scenario step submits the registration form using data from the CSV file and validates the registration success status.

info

The CSV file should have columns for name, email, and phone with corresponding values for each test case.