A Complete Guide to Functional Testing

While functional testing does encourage reliability and ease of use in the end product, it opens avenues of testing through which usability, accessibility, and performance of applications can be defined. This, along with the fact that the most important tool for usability testing is 70% of users who abandon carts due to defects in their UX, is notably significant. Functional testing specifically addresses this facet of UX, targeting guaranteeing that users achieve the expected outcomes in its use of the app.

Introduction to Functional Testing

Functional testing is defined by the adherence to functional or requirement specifications, which set the standards for quality assurance (QA) engineers during the test phase. These specifications, detailed in documents, guide QA engineers through necessary actions to affirm the software system's compliance, including the evaluation of specific business scenario-based tests for a comprehensive system analysis. Thus, functional testing can be bifurcated into:

Requirements-based functional testing: Focuses on validating the software system's functionality.

Business scenarios-based functional testing: Concentrates on the software system's performance in business-related scenarios.

Functional testing at the core is an exercise of confirming that a software system functions per its specified requirements. This involves making input data to the software system and checking the output without looking into the source code of the system. Primarily employing black box testing techniques, it encompasses the examination of APIs, security measures, client/server interactions, databases, user interfaces (UI), and other pivotal functionalities. Functional tests can be executed both manually and through automation.

What Does Functional Testing Cover?

Functional testing primarily scrutinizes the software system's key functionalities, focusing on aspects such as:

·         Accessibility: Ensures the system's compliance with accessibility standards.

·         Error Conditions: Verifies that the system delivers meaningful error messages for troubleshooting.

·         Mainline Functions: Confirms the proper functioning of the system's core features.

·         Basic Usability: Assesses the system's navigability and ease of use for end-users.

Types of Functional Testing

Functional testing encompasses various methods, including:

• Unit Testing: Conducted by developers to check if individual components meet specified requirements through script testing.

• Smoke Testing: Also known as build verification testing, this initial testing phase assesses the stability of a new build.

• Sanity Testing: Follows smoke testing to ensure all critical functionalities operate smoothly.

• Regression Testing: Makes sure that the new code is added, bugs are fixed, or enhancements are made without impacting the functionality that was already there.

• Integration Testing: Assesses the cooperative functionality of combined software modules.

• Usability Testing: This involves real users testing the product to get an insight into its user-friendliness and to collect feedback for further modifications.

Functional Testing Tools

A myriad of tools facilitates functional testing, each boasting unique features. Notable mentions include Selenium, TestComplete, UFT, JUnit, NUnit, Cucumber, and Postman. These tools cater to various testing needs, from web applications to unit testing, and play a crucial role in the software development lifecycle.

Functional Testing Workflow

The workflow for conducting functional testing typically involves:

• Defining the software system aspects to be tested.

• Generating input data tailored to the specific functionalities under test.

• Identifying acceptable output criteria.

• Executing the test cases.

• Comparing actual outcomes with expected results to assess conformity.

Example: Functional Testing Use Case

Consider a login scenario for an HRMS portal, where users input credentials. The testing framework would include examining field validations, user feedback for incorrect inputs, and ensuring the login process leads appropriately to the home page or returns to the login page as intended.

Pros and Cons of Functional Testing

Advantages:

·         Replicates real-world use scenarios, focusing on the operating system, browsers, and system specifications.

·         Directly addresses system structure to deliver high-quality, customer-focused products.

·         Minimizes risks through risk-based testing.

Limitations:

·         Overlooks performance metrics like throughput time and responsiveness.

·         May involve redundant testing or overlook logical errors due to requirement-based testing focus.

Automated Functional Testing

Automation in functional testing enhances efficiency, saves time, and optimizes processes. It is essential for companies seeking scalable solutions to invest in automated testing tools and processes, which not only improve test efficiency but also product quality.

Moving Forward with Automation

Key considerations for automation include tool selection, identifying test cases for automation, dedicating a team to automation tasks, employing data-driven testing strategies, and ensuring UI changes do not adversely affect test outcomes.

Functional Testing with Appinventors

Appinventors offers professional functional testing services, providing detailed insights and identifying root causes for issues, thereby significantly improving development timelines and market readiness.

FAQs

Difference between functional and integration testing?

Functional testing focuses on application functionalities, while integration testing ensures that combined modules work seamlessly together.

What is defect severity?

It measures the impact of a defect on the application's functionality, categorized into critical, major, medium, and low.

Build vs. Release?

A build is an executable file for testing, while a release is the final version of the application ready for client delivery, encompassing several builds.