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Network Mocking and Request Interception

SHAFT Engine exposes browser network interception through driver.browser().interceptRequest(). Use it to match outgoing browser requests, replace responses with controlled test data, or let real responses continue and validate them with SHAFT API validations.

info

Network interception relies on Selenium DevTools support. Use a DevTools-capable browser, such as Chrome or Edge, when running tests that require this feature.

Use Cases​

ScenarioRecommended approach
Test error states (500, 404).respond().statusCode(500).perform()
Test empty states (no data).respond().jsonBody("{\"items\":[]}").perform()
Block analytics / tracking callsMatch the analytics URL and return a 204 response
Validate real API responses from the browser.assertResponse(...) or .verifyResponse(...)
Inject controlled test dataMatch the request and return a fixed JSON payload

Mock Responses​

Build the request matcher first, then configure the mocked response. Register the rule before navigating to the page that sends the request.

NetworkMocking.java
import com.shaft.driver.SHAFT;

SHAFT.GUI.WebDriver driver = new SHAFT.GUI.WebDriver();

driver.browser()
        .interceptRequest()
        .get()
        .urlContains("/api/users")
        .queryParam("role", "admin")
        .header("X-Test", "yes")
        .respond()
        .statusCode(200)
        .jsonBody("{\"users\":[{\"name\":\"Mock User\"}]}")
        .perform();

driver.browser().navigateToURL("https://example.com/dashboard");

Validate Real Responses​

Use assertResponse() for hard assertions or verifyResponse() for soft verifications. The real request continues to the server, then SHAFT validates the received response.

NetworkValidation.java
driver.browser()
        .interceptRequest()
        .get()
        .pathEquals("/api/users")
        .assertResponse(response -> response
                .extractedJsonValue("users.size()")
                .isEqualTo("1")
                .perform());

Request Matchers​

Use the built-in matchers for common request fields:

RequestMatchers.java
driver.browser()
        .interceptRequest()
        .post()
        .pathContains("/api/checkout")
        .urlMatches("https://example.com/.*/checkout")
        .queryParam("source", "web")
        .header("Content-Type", "application/json")
        .bodyContains("\"coupon\":\"SUMMER\"")
        .matching(request -> request.getUri().contains("/api/"))
        .respond()
        .statusCode(202)
        .perform();

Complete Example​

NetworkMockingTest.java
import com.shaft.driver.SHAFT;
import org.openqa.selenium.By;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;

public class NetworkMockingTest {
    private SHAFT.GUI.WebDriver driver;

    @BeforeMethod
    public void setup() {
        driver = new SHAFT.GUI.WebDriver();
    }

    @Test
    public void testEmptyUserList() {
        driver.browser()
                .interceptRequest()
                .get()
                .urlContains("/api/users")
                .respond()
                .statusCode(200)
                .jsonBody("{\"users\":[]}")
                .perform();

        driver.browser().navigateToURL("https://example.com/users");
        driver.assertThat(By.id("emptyState")).text().contains("No users found");
    }

    @Test
    public void testServerErrorHandling() {
        driver.browser()
                .interceptRequest()
                .get()
                .urlContains("/api/users")
                .respond()
                .statusCode(500)
                .jsonBody("{\"error\":\"Internal Server Error\"}")
                .perform();

        driver.browser().navigateToURL("https://example.com/users");
        driver.assertThat(By.id("errorBanner")).text().contains("Something went wrong");
    }

    @AfterMethod
    public void teardown() {
        driver.quit();
    }
}

Advanced Predicate API​

mock() and intercept() remain available for advanced use cases that need direct Selenium HttpRequest predicates and HttpResponse objects.

PredicateApi.java
import org.openqa.selenium.remote.http.Contents;
import org.openqa.selenium.remote.http.HttpResponse;

driver.browser().mock(
        request -> request.getUri().contains("/api/users"),
        new HttpResponse()
                .setStatus(200)
                .addHeader("Content-Type", "application/json")
                .setContent(Contents.utf8String("{\"users\":[]}"))
);
note

Interception rules are scoped to the current browser session. They are cleared automatically when the driver is quit, or explicitly with driver.browser().clearNetworkInterceptors(). If multiple rules match the same request, the latest registered rule wins.