Testing Solutions

Functional Testing

Functional testing with test IO combines automated test case execution with the intuitive perspective of professional testers.

What is Functional Testing?

Functional testing represents the reality check for software developer innovation and creativity. It’s the point at which the hard work to develop something turns to asking the hard questions such as “does this actually work,” “can the user do what we expected,” or “are there ways in which this should work that we hadn’t even considered yet?”

Functional Testing with test IO

Shortchange functional testing at your own peril. We’d liken it to leaving a toddler alone in a room with matches, firecrackers, and an uncapped gas can — there’s a big risk that something will go “boom.” Functional testing makes sure it isn’t your recently released app or app update that is blasted. test IO provides the essential functional testing techniques your product requires and thousands of highly skilled testers to make sure it is ready for the next step.

Fundamentals of Functional Testing

Functional testing ensures that your software works as designed from the user’s perspective by checking the application from head to toe, without a prior understanding of how the code functions internally. You might consider it a little like looking in the mirror and making sure that you have all items of clothing on and accounted for. You’re not making sure the clothing was acquired legally or put away in the right drawers, but that you’re actually wearing a belt (lest your pants fall down) and underwear (in case of the failure of your belt).

Functional testing is the equivalent in that you’re checking every function of the application works as required before the product is released to the public. Uncovering bugs in testing is preferable before the product goes wide scale. Debugging is more manageable in a contained space after all.

“1/4 users abandoned an app after one use in 2016.” — Localytics

Functional testing puts you in the head of the user and helps you identify glitches that could ruin user experience (and ultimately the success of your app).

Good functional testing not only tests that everything functions as expected to, but also uncovers unanticipated issues. In an ideal world, you would have a list of every test case covering every behavior possible in your software, but because most organizations don’t live in the ideal world, functional testing demands creativity and empathy from testers. With the pace of innovation in agile environments, for instance, it can be too easy to make assumptions from user stories about how software “should” work. Only people who think like testers will veer off this happy path to discover the spec based on how the software actually works. Thus, in effect, functional testing assures the developers that they are not inadvertently “should-ing” on the future of their latest and greatest application offering.

Overall functional testing involves checking:

  • User Interface — Testing whether a user can navigate the app without any difficulties. Anticipating what the user wants to do and planning for them to be able to do so is a valuable step in the software development process. Considering, for instance, the criticality of a good impression on app users on their first visit testing the simplicity and efficacy of the sign up process simple and seeking out undetected bugs can have a big impact on retention.
  • Error conditions — Determining that error messages are displayed as needed and errors are handled gracefully. This becomes particularly important for story-driven agile teams, where stories often focus on “happy outcomes” to the exclusion of errors.
  • Text handling — Considering input, copying, pasting, and editing for text including extended characters, special fonts and non-Latin scripts.

Functional testing requires you to identify the test data, compute the expected outcomes, execute test cases, and compare actual and expected results to determine in practical terms what the product does and whether or not it is doing so as planned.

Why Functional Testing?

Effective functional testing replicates user and business requirements for the software. The primary objective is to simulate the actual way the software system or application will be used. This is no longer a bunch of developers or product managers imagining “what if…” or “the user might…” Rather this intends to take out the assumptions and identify what exactly each function is meant to do, what it will look like if it functions correctly, and determine whether or not it actually does that.

Stages of the testing process

The familiar testing pyramid depicts several forms and types of testing, all of which are crucial to the creation of functional software, but only functional testing ensures that all of the parts come together so users can meet their goals. For instance, function testing can highlight:

  • Missing functionality: when the application is not capable of doing what was expected or is not doing what a user will want it to do (when it should).
  • User interface errors: when data is received but the user cannot act on it because of problems in the user interface.
  • Incorrect specifications: when specifications are incomplete, incorrect or inconsistent.
  • Errors communicating among components: when components of a system work correctly in isolation but don’t come together properly.

The functional tester, after all, is not blinded by excitement over building a new feature in the code, or burdened with knowledge of how the code was built. Instead, the tester’s goal is quality assurance and making sure the software is released to users with full functionality — doing what the coders intended and perfectly.

Successful QA testers will also employ both positive and negative testing. While positive testing sets out to make sure that a software application will perform as planned, negative testing does the opposite. Negative testing is a little like trying to get the software to beg for mercy. Determining in advance what causes the software to fail, lets you release more stable and reliable software. Identifying potential problems proactively also allows developers to outline in advance what actions the user cannot take and plan to handle issues in a more user friendly way.

The average app mostly loses its entire user base within a few months. — Andrew Chen

Types of Functional Testing

Software testing isn’t a one-size-fits-all proposition. The right testing techniques should match your requirements at each stage of your process. Fittingly, there are many common types of functional testing. These include:

Smoke testing

Tests if major pieces of the software work well enough to move on to the next stage of testing. Smoke tests are often automated and run as part of a continuous build process, with the failure of a smoke test indicating that the build is not ready to be staged, performance tested, regression tested, or otherwise worked on until the smoke test passes.

Sanity testing

Another non-comprehensive test confirming that any code changes have not created new, serious issues. Sanity tests are typically performed to see whether a new build, often one with bugs fixes, has fixed problems with breaking in strange or unexpected ways. Unlike a smoke test, a sanity test is typically performed by a human tester with knowledge of what has changed in the application.

Compatibility testing

Determines whether a product works across the devices or environments it’s required to support. A compatibilty test often works from a reference platform that is known to work. For example, a web application might work in the latest version of Chrome for Mac, then be tested for compatibility with Firefox, Safari, and Edge on different platforms.

Regression testing

A more in-depth version of smoke testing to determine whether code changes have a negative effect on software functionality or even brings forth problems that were hidden before. Regresssion tests are often automated or semi-automated, wtih human testers covering parts of an application that change rapidly or are heavily front-end dependent.

User acceptance testing

Although this is not typically considered functional testing, in situations where functional specifications are not documented in detail — as is often the case for agile development teams — the two complement each other and may take place concurrently. For example, crowdtesting through a company such as test IO is one great way to gain authentic, objective user input from intelligent users who are not as close to the product development while simultaneously ensuring that user-facing functions work.

Regardless of the approach taken, functional testing shouldn’t stop at the first release of a software application. As new features are added or you change the way your app works, functional testing should continue to verify that the software meets its requirements.

Even if your software was cutting edge when released, with the pace of technological innovation, you need to be sure it remains supported and usable. Browsers change, the OS’s change, and the third party software that you link to changes. Any of these evolutions can create issues you need to address.

“Of the more than 1.5 million apps in the Google Play store, only a few thousand sustain meaningful traffic.” — Andrew Chen

Functional Testing Tools

Functional testing is critical to quality assurance. Some functional testing is straightforward to automate, but an overall approach to functional testing typically combines automated and human-driven elements.

Test automation lets software teams design, write, execute, and review tests for predefined actions. Common actions that do not change frequently can be automated, but (as we’ve seen from the testing pyramid) most experts recommend automating lower level tests in preference to actions taken through the user interface.

Of course, automated tests are only as good as the input data, and only as stable as the software they’re testing. QA departments may use test data generators to gain new data insights that both manual and automated testers can use to try even harder to make their beloved software go boom. These generated data sets offer the advantage of forcing the software to handle unexpected use cases that the testers might have difficulty anticipating otherwise.

Functional testing efforts today also benefit from the availability of hosted test environments, which enable scaled up testing at high speeds, and test case management tools to record and report on status, progress, issue resolution procedures and more.

Crowdtesting further enables functional testing to find problems the developers didn’t anticipate. Rather than simulating the real-world user interaction with the software, crowdtesting sees informed, experienced professional testers anticipate the user experience on various devices and platforms in diverse locations.

Functional Testing with test IO

As of March 2017, there were over 6.5 million apps available to download, according to Localytics. It’s a highly congested environment and with the high expectations users have today for their applications, functional testing is essential to software success.

test IO combines functional test case execution with exploratory testing by a variety of highly skilled professional testers. Don’t worry, though, our exploratory testers know the importance of having a clear, reasonable mission, identifying high and low-value tests, and documenting their testing efforts. We also work to match our customers’ requirements to the right set of testers and testing techniques.

Our savvy QA testers know apps and bring a human touch to their interactions with your software. Testing with real devices under real conditions — you specify the devices, browsers, and operating systems that need the most functional testing — they provide the necessary stamp of approval for your product. With the “A-OK” of real, human end users, you can ship with confidence.

Not Sure if You are Ready for Functional Testing with test IO?

Check out these other testing solutions

Regression Testing
Learn More
Usability Testing
Learn More
Beta Testing
Learn More