Automation Testing Interview Questions for Hardware &amp; semiconductors Companies

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Use a DriverManager with a ThreadLocal<WebDriver>, created in @BeforeMethod and removed in @AfterMethod. Page objects receive the driver through the constructor or get it from DriverManager.getDriver(). Constructor injection is cleaner and easier to test. Never store the driver in a static field shared by all threads, or parallel tests will control each other's browsers.

What is a DataProvider in TestNG?

TestNG FrameworkMedium

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@DataProvider returns Object[][]; a @Test(dataProvider = "name") method runs once per row — the basis of data-driven tests, often reading Excel or JSON.

Write a Dockerfile that runs a Maven and TestNG test suite.

Selenium Grid & DockerMedium

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FROM maven:3.9-eclipse-temurin-21 WORKDIR /app # cache dependencies first for faster rebuilds COPY pom.xml . RUN mvn -q dependency:go-offline COPY src ./src COPY testng.xml . ENV GRID_URL=http://selenium-hub:4444 CMD ["sh", "-c", "mvn test -Dgrid.url=$GRID_URL -Dsurefire.suiteXmlFiles=testng.xml"]

How would you design a CI pipeline for nightly regression?

API Testing and CI/CDHard

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Schedule the job, spin up environments or containers, run suites in parallel, store reports and screenshots, notify failures on Slack or email and track trends.

Your company is debating a cloud device farm versus an in-house device lab. How do you advise?

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A cloud farm gives hundreds of device and OS combinations, parallel capacity and no hardware maintenance, but costs per minute, adds network latency and may raise data privacy concerns. An in-house lab is cheaper over time for a small fixed set of devices and gives full control, but needs USB hubs, OS updates, battery care and someone to maintain it. Many teams keep a few local devices for debugging and use the cloud for wide coverage.

What are the Actions class use cases?

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Mouse and keyboard actions such as hover, drag and drop, double click, right click and key combinations, built with moveToElement(...).perform().

How do you upload a file with REST Assured?

REST AssuredMedium

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Use multipart: given().multiPart("file", new File("src/test/resources/report.pdf"), "application/pdf").formParam("type", "invoice").when().post("/upload").then().statusCode(200). REST Assured sets the multipart/form-data content type automatically. Verify both the status and the response, such as the returned file id or size, and test edge cases like empty, oversized and wrong-type files.

What new features came with Selenium 4?

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Relative locators, improved Grid, W3C compliance, new window or tab creation, Chrome DevTools Protocol access and element-level screenshots.

How do you handle StaleElementReferenceException?

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Re-locate the element after the DOM refreshes, use explicit waits for the refreshed element, don't keep element references for long, or wrap the action in retry logic.

How do you set up distributed load testing in JMeter?

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One controller machine coordinates several worker machines that generate the load. On each worker start jmeter-server with the same JMeter and Java versions, place CSV files locally and open the RMI ports in the firewall. On the controller list the workers in remote_hosts in jmeter.properties, or pass -R host1,host2, and run in non-GUI mode with -r or -R. Remember that thread counts multiply per worker, so 100 threads on 4 workers gives 400 users.

How do you run Appium tests in parallel on several Android devices?

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Give each device its own session: unique appium:udid, a separate appium:systemPort for UiAutomator2 and, for hybrid apps, a separate chromedriverPort. Store the driver in a ThreadLocal so threads never share it. Pass device details through TestNG parameters or a DataProvider and run with parallel="tests", one test tag per device. One Appium server can handle several sessions, or use a Selenium Grid 4 with Appium nodes or a cloud device farm for larger matrices.

What is TestNG and why is it used with Selenium?

TestNG FrameworkEasy

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A test framework offering annotations, grouping, prioritisation, parallel runs, data providers and reports, which structure and scale Selenium tests.

What is Selenium Grid and why use it?

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It runs tests in parallel across multiple machines and browsers using a hub and nodes, cutting execution time and increasing browser coverage.

How do you pass parameters from testng.xml?

TestNG FrameworkMedium

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Define parameter name and value in the XML and read them with @Parameters in the test or configuration method.

What is the Maven Failsafe plugin and how is it different from Surefire?

Git, Maven and JenkinsMedium

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Surefire runs unit tests in the test phase and stops the build as soon as tests fail. Failsafe runs integration tests in the integration-test phase and checks results later in the verify phase, so post-integration-test steps, like stopping a server or Docker containers, still run after failures. By default Failsafe picks classes named *IT. Many teams run UI and API suites through Failsafe with mvn verify for that reason.

What is the difference between Comparable and Comparator in Java?

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Comparable defines the natural order inside the class (compareTo); Comparator defines custom orders externally (compare), useful for sorting test data in several ways.

What are Cucumber hooks and how are they different from Background?

Cucumber and BDDMedium

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Hooks are Java methods annotated with @Before, @After, @BeforeStep and @AfterStep that run around scenarios or steps. Background is visible in the feature file and describes business preconditions; hooks are hidden technical setup such as starting the browser, cleaning data or attaching screenshots. Hooks can be ordered with the order attribute and filtered by tag expressions, for example @Before("@ui").

What is Postman and how do you automate with it?

API Testing and CI/CDMedium

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An API client. Add tests in JavaScript, use environments and collections, and run them with Newman in a CI pipeline.

Your 200 mobile tests across six devices take too long to finish. How would you speed them up?

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Run devices in parallel with one thread per device, each with its own udid, systemPort or wdaLocalPort. Use deep links or API calls to reach the screen under test instead of navigating through the UI every time. Prefer noReset with explicit data cleanup over reinstalling the app. Replace XPath with accessibility ids. Split the suite so pull requests run a small smoke set on emulators while the full device matrix runs nightly.

Developers changed a field from a number to a string and your tests did not catch it. How do you prevent this?

REST AssuredHard

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Add JSON schema validation for key responses so type changes fail immediately, and deserialize into typed POJOs, which fail when types do not match. For services with multiple consumers, introduce contract tests so providers learn about breaks before deploying. Also ask for API changes to be shared in pull requests or a changelog that QA reviews.

Difference between ArrayList and LinkedList?

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ArrayList has fast random access and slower inserts in the middle; LinkedList has fast inserts and deletes but slow access by index.

What is a DataTable in Cucumber and how do you use it?

Cucumber and BDDMedium

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A DataTable passes a table written under a step into the step definition. You can read it as List<String>, List<Map<String,String>>, Map<String,String> or convert rows into objects with a @DataTableType method. For example a step that creates several users can take a table of name, role and email. Unlike Scenario Outline, a DataTable feeds data into one step and the scenario runs once.

How do you make page objects work with dynamic locators, such as a row containing a given name?

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Write a method that builds the locator from a parameter, for example private By rowFor(String name) { return By.xpath("//tr[td[normalize-space()='" + name + "']]"); }, and expose actions like deleteUser(name). Keep the template in the page class, not in tests. Escape quotes if names may contain them, and prefer CSS with data attributes when the application provides them.

What is the Optional class in Java and where is it useful in test code?

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Optional is a container that may or may not hold a value, introduced in Java 8 to avoid returning null. In test code it suits lookups that can legitimately find nothing, such as finding a row in a table or reading an optional config key. Callers use orElse, orElseThrow or ifPresent instead of null checks. For example, findRowByName(name).orElseThrow(() -> new AssertionError(name + " not found")) gives a clear failure message.

How do you validate a JSON response in REST Assured?

REST AssuredMedium

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Use then().statusCode(200).body("data.id", equalTo(5)), or extract() the response and assert fields with JsonPath.

What are Java collections and which ones do testers use most?

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ArrayList and LinkedList for lists, HashSet for unique values, HashMap for key-value test data, and Iterator for traversing them, for example collecting web elements in a list.

How do you verify that the correct page has loaded in POM?

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Give each page an isAt() or waitUntilLoaded() method that waits for a unique element, page title or URL fragment. Call it in the constructor or right after navigation. If it fails, throw a clear error such as "Expected Cart page but URL was /login". This catches navigation problems at the right point instead of failing later with a confusing locator error.

How do you test deep links in a mobile app with Appium?

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On Android use the mobile: deepLink command with the URL and package, for example driver.executeScript("mobile: deepLink", Map.of("url", "shop://product/42", "package", "com.example.shop")). On iOS simulators driver.get with the custom URL opens it, though Safari may show a confirm dialog to handle. Then assert that the correct screen and data are shown. Deep links are also a great shortcut to reach deep screens quickly in other tests.

An API test passes alone but fails when the suite runs in parallel. What could be wrong?

REST AssuredHard

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Likely shared state. Common causes are static RestAssured settings changed by one test, shared test data like the same user being updated by two tests, token reuse after another test logged out, or rate limits. Fix by using per-test RequestSpecification instead of global statics, creating unique data per test, isolating tokens, and checking server rate-limit responses such as 429.

Write Appium Java code to perform a vertical swipe using W3C Actions.

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// Swipe up from 80% to 20% of the screen height Dimension size = driver.manage().window().getSize(); int x = size.width / 2; int startY = (int) (size.height * 0.8); int endY = (int) (size.height * 0.2); PointerInput finger = new PointerInput(PointerInput.Kind.TOUCH, "finger"); Sequence swipe = new Sequence(finger, 1); swipe.addAction(finger.createPointerMove(Duration.ZERO, PointerInput.Origin.viewport(), x, startY)); swipe.addAction(finger.createPointerDown(PointerInput.MouseButton.LEFT.asArg())); swipe.addAction(finger.createPointerMove(Duration.ofMillis(600), PointerInput.Origin.viewport(), x, endY)); swipe.addAction(finger.createPointerUp(PointerInput.MouseButton.LEFT.asArg())); driver.perform(List.of(swipe));

How do you validate a response against a JSON schema in REST Assured?

REST AssuredMedium

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Add the json-schema-validator dependency, place the schema file in src/test/resources, and assert with then().body(matchesJsonSchemaInClasspath("user-schema.json")). Schema validation checks field types, required fields and structure, so it catches contract changes that value checks might miss. It complements, not replaces, assertions on business values like status or totals.

How do you group tests?

TestNG FrameworkMedium

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Tag tests with groups = {"smoke","regression"} and include or exclude them in testng.xml to run chosen sets.

A stakeholder asks whether the system can handle 10,000 users. How do you plan the performance test?

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First clarify what 10,000 users means: concurrent sessions, users per hour or requests per second, and which journeys they perform. Use production analytics to build the workload mix and think times, then agree on SLAs like 95th percentile under two seconds and errors under one percent. Prepare a production-like environment and data, plan baseline, load, stress and soak runs, set up monitoring, and share a report with clear limits and bottlenecks.

What is RemoteWebDriver and how is it different from ChromeDriver?

Selenium Grid & DockerEasy

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ChromeDriver starts and controls a browser on the same machine as the test. RemoteWebDriver sends the same WebDriver commands over HTTP to a remote endpoint, such as a Selenium Grid, a Docker container or a cloud provider, which starts the browser elsewhere. You pass the Grid URL and browser options, and the rest of the test code stays the same. ChromeDriver itself actually extends RemoteWebDriver.

What is the difference between ThreadLocal and a synchronized block in Java?

Core Java for TestersHard

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A synchronized block lets only one thread at a time run a piece of code that touches shared data, so threads wait for each other. ThreadLocal avoids sharing altogether by giving each thread its own copy of a variable. In parallel test frameworks ThreadLocal<WebDriver> is preferred because each thread needs its own browser, and locking would serialise tests. Always call remove() after quitting to avoid leaks in thread pools.

How do you run JMeter tests in a Jenkins pipeline and fail the build when an SLA is breached?

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Run JMeter in non-GUI mode in a pipeline stage, ideally inside a Docker image with a pinned JMeter version, and archive the JTL and HTML report. Enforce SLAs with Duration Assertions or a JSR223 check, or parse the JTL in a script that compares 95th percentile and error rate with thresholds and exits non-zero. The Jenkins Performance plugin can also mark builds unstable or failed based on thresholds and trends.

Write Selenium code to wait for a loader to disappear and then click a button.

Selenium WebDriverEasy

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WebDriverWait wait = new WebDriverWait(driver, Duration.ofSeconds(15)); wait.until(ExpectedConditions.invisibilityOfElementLocated( By.cssSelector(".spinner"))); wait.until(ExpectedConditions.elementToBeClickable( By.id("placeOrder"))).click();

POST vs PUT vs PATCH?

API Testing and CI/CDMedium

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POST creates a resource, PUT replaces the whole resource (idempotent) and PATCH updates part of it.

Response time grows slowly over a six-hour soak test while load stays constant. What does it suggest?

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A steady rise under constant load usually indicates a resource leak, such as memory not being freed, growing caches, unclosed database connections or threads, or log and temp files filling disk. Check heap usage and garbage collection trends, connection pool counts and open file handles over time. A heap dump comparison can show which objects grow. Share the evidence with developers, since such issues rarely appear in short tests.

How do you handle waits inside page objects?