Agile Testing: A Practical Guide for Testers and Agile Teams

While this provided a lot of test coverage, it didn’t actually test the reason the device was used, which was to read data from RTUs. A simulator was written in Ruby with a FOX (FXRuby) GUI. This allowed mock data to be fed into the device. Because the simulator could be controlled remotely, it was incorporated into automated tests that exercised the embedded device’s ability to read data, respond to error conditions, and generate alarms when the input data exceeded a predetermined threshold.

Embedded testing is highly technical, but with the power provided by the simulator, the whole team was able to participate in testing the device. The simulator was written to support testing for the test team, but the programmer for the firmware found it valuable and used it to help with his development efforts as well. That was a positive unexpected side effect. Quadrant 2 tests that support the team may incorporate a variety of technologies, as they did in this project.

Critiquing the Product with Business-Facing Tests

The business-facing tests that critique the product are outlined in this section.

Exploratory Testing

The automated tests were simple and easy for everyone on the team to use. Individual test scripts could be run to set up specific conditions, allowing effective exploratory testing to be done without having to spend a lot of time manually entering data. This worked for all three test frameworks: functional, web services, and embedded.

Exploratory testing, usability testing, and other Quadrant 3 tests are discussed in Chapter 10, “Business-Facing Tests that Critique the Product.”

The team performed exploratory testing to supplement the automated test suites and get the best coverage possible. This human interaction with the system found issues that automation didn’t find.

Usability testing was not a critical requirement for the system, but the testers watched so that the interface made sense and flowed smoothly. The testers used exploratory testing extensively to critique the product. The product engineer also used exploratory testing for his solution verification tests.

Testing Data Feeds

As shown in Figure 12-2, the data from the system is available on a JMS queue, as well as the web browser. To test the JMS queue, the development group wrote a Java proxy. It connected to a queue and printed any arriving data to the console. They also wrote a Ruby client that received this data via a pipe, which was then available in the Ruby automated test system.

Emails were automatically sent when alarm conditions were encountered. The alarm emails contained both plain text email and email with attachments. The MIME attachments contained data useful for testing, so a Ruby email client that supported attachments was written.

The End-to-End Tests

Quadrant 3 includes end-to-end functional testing that demonstrates the desired behavior of every part of the system. From the beginning, it was apparent that correct operation of the whole Remote Data Monitoring system could only be determined when all components were used. Once the simulator, embedded device tests, web services tests, and application tests were written, it was a relatively simple matter to combine them to produce an automated test of the entire system. Once again, Excel spreadsheets were used to hold the test data, and Ruby classes were written to access the data and expected results.

The end-to-end tests were complicated by the unpredictable response of the satellite transmission path. A predefined timeout value was set, and if the test’s actual value did not match the expected value, the test would cycle until it matched or the timeout was reached. When the timeout expired, the test was deemed to have failed. Most transmission issues were found and eliminated this way. It would have been highly unlikely that they would have been found with manual testing, because they were sporadic issues.

Because end-to-end tests such as these can be fragile, they may not be kept as part of the automated regression suite. If all of the components of the system are well covered with automated regression tests, automated end-to-end tests might not be necessary. However, due to the nature of this system, it wasn’t possible to do a full test without automation.

User Acceptance Testing

User Acceptance Testing (UAT) is the final critique of the product by the customer, who should have been involved in the project from the start. In this example, the real customer was in France, thousands of miles from the development team. The team had to be inventive to have a successful UAT. The customer came to work with the team members a couple of times during the year and so was able to interact with the team a little easier than if they’d never met.