Welcome!

Java IoT Authors: Liz McMillan, Yeshim Deniz, Pat Romanski, Elizabeth White, Carmen Gonzalez

Related Topics: Java IoT

Java IoT: Article

Using Aspects to Unit-Test the Integration of Third-Party Components

Creating proxies to exercise the branches of our code

Unit testing is hard. There I said it. Although I have been developing software for the past 18 years I still find that putting my applications through their paces via unit testing is difficult. I have learned the lesson (I'm sure like many of you) the hard way. Unit testing is probably the most important part of software development. We all get caught in the trap once in a while when we believe that there is no need to test a piece of software we just wrote. We convince ourselves it is too hard to test, the rest of the application is solid, and that if there are any real errors in the code it will be discovered by the QA department. You know and I know this is a bad argument. Of course once the application is in production it is the piece of code that we didn't test that causes system failures.

There's no good reason for not unit testing all pieces of an application. Unit testing is the only way we can be assured that everything works as intended. It is the only way that others can take over our code, change it, and be confident that they didn't break anything unintentionally. Unfortunately fewer and fewer applications are truly standalone. Almost every application that I develop requires the interaction of third-party libraries as well as third-party systems. Creating n-tiered systems is not the exception anymore it's the norm. It's easy to test code that you wrote. You know how to control the inputs and you know the expected outputs.

What is not easy is testing the integration of third-party components and the range of their possible outputs. This is the case when interacting with Web Services, scraping Web pages, information providing systems, etc. You read the third-party's specification that explains their inputs and their expected results. How do you control the third-party environment for every possible scenario that can occur? This is especially difficult when certain results only occur intermittently such as certain times of the year. Even more difficult is how you test for failure scenarios. You can't cause the third-party system to fail but in case that system does fail you want to protect your users. You don't want your user's to have any of their data corrupted; you don't want your system to fail especially if it's a 24x7 system and must be up all the time; and you minimally want to inform your users that the system is not functioning properly due to the failure of an outside system.

One approach for testing third-party components is to create a proxy. All interactions with the outside system are done via an interface and communication with that system is done via an implementation of that interface. Now you are just testing the interface to make sure that you can handle all expected and unexpected results from that interface. When writing your test code you create a test implementation of that interface that mimics the true third-party implementation.  The reasoning behind this approach is that in the end as long as your program interacts correctly with the interface then all is well. This statement is not untrue. The problem with it is that you wind up writing code that is intended only for testing, but is now part of the whole system. It is more code that you have to maintain and it bloats your released application.

More Stories By Mark Nadelson

Mark Nadelson has been working as a software developer for the past 18 years in a variety of industries including telecommunications, Internet, and finance. He has published numerous articles as well as two books. He enjoys exploring new technologies and new techniques to solve complex problems.

Comments (1) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


Most Recent Comments
immohuneke 01/06/09 08:14:24 AM EST

A well written article, an ingenious solution to a real problem often encountered in testing and a neat answer to those who claim that AOP is just a solution looking for a problem. However, I found only the first five listings in the file "Nadelson_source.rtf", which makes the last part of the article harder to understand. Please could you check whether it's all there?

@ThingsExpo Stories
The age of Digital Disruption is evolving into the next era – Digital Cohesion, an age in which applications securely self-assemble and deliver predictive services that continuously adapt to user behavior. Information from devices, sensors and applications around us will drive services seamlessly across mobile and fixed devices/infrastructure. This evolution is happening now in software defined services and secure networking. Four key drivers – Performance, Economics, Interoperability and Trust ...
Data is an unusual currency; it is not restricted by the same transactional limitations as money or people. In fact, the more that you leverage your data across multiple business use cases, the more valuable it becomes to the organization. And the same can be said about the organization’s analytics. In his session at 19th Cloud Expo, Bill Schmarzo, CTO for the Big Data Practice at Dell EMC, introduced a methodology for capturing, enriching and sharing data (and analytics) across the organization...
SYS-CON Events announced today that T-Mobile will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. As America's Un-carrier, T-Mobile US, Inc., is redefining the way consumers and businesses buy wireless services through leading product and service innovation. The Company's advanced nationwide 4G LTE network delivers outstanding wireless experiences to 67.4 million customers who are unwilling to compromise on ...
The explosion of new web/cloud/IoT-based applications and the data they generate are transforming our world right before our eyes. In this rush to adopt these new technologies, organizations are often ignoring fundamental questions concerning who owns the data and failing to ask for permission to conduct invasive surveillance of their customers. Organizations that are not transparent about how their systems gather data telemetry without offering shared data ownership risk product rejection, regu...
Bert Loomis was a visionary. This general session will highlight how Bert Loomis and people like him inspire us to build great things with small inventions. In their general session at 19th Cloud Expo, Harold Hannon, Architect at IBM Bluemix, and Michael O'Neill, Strategic Business Development at Nvidia, discussed the accelerating pace of AI development and how IBM Cloud and NVIDIA are partnering to bring AI capabilities to "every day," on-demand. They also reviewed two "free infrastructure" pr...
New competitors, disruptive technologies, and growing expectations are pushing every business to both adopt and deliver new digital services. This ‘Digital Transformation’ demands rapid delivery and continuous iteration of new competitive services via multiple channels, which in turn demands new service delivery techniques – including DevOps. In this power panel at @DevOpsSummit 20th Cloud Expo, moderated by DevOps Conference Co-Chair Andi Mann, panelists will examine how DevOps helps to meet th...
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place June 6-8, 2017, at the Javits Center in New York City, New York, is co-located with 20th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry p...
With billions of sensors deployed worldwide, the amount of machine-generated data will soon exceed what our networks can handle. But consumers and businesses will expect seamless experiences and real-time responsiveness. What does this mean for IoT devices and the infrastructure that supports them? More of the data will need to be handled at - or closer to - the devices themselves.
Grape Up is a software company, specialized in cloud native application development and professional services related to Cloud Foundry PaaS. With five expert teams that operate in various sectors of the market across the USA and Europe, we work with a variety of customers from emerging startups to Fortune 1000 companies.
Financial Technology has become a topic of intense interest throughout the cloud developer and enterprise IT communities. Accordingly, attendees at the upcoming 20th Cloud Expo at the Javits Center in New York, June 6-8, 2017, will find fresh new content in a new track called FinTech.
Today we can collect lots and lots of performance data. We build beautiful dashboards and even have fancy query languages to access and transform the data. Still performance data is a secret language only a couple of people understand. The more business becomes digital the more stakeholders are interested in this data including how it relates to business. Some of these people have never used a monitoring tool before. They have a question on their mind like “How is my application doing” but no id...
SYS-CON Events announced today that Interoute, owner-operator of one of Europe's largest networks and a global cloud services platform, has been named “Bronze Sponsor” of SYS-CON's 20th Cloud Expo, which will take place on June 6-8, 2017 at the Javits Center in New York, New York. Interoute is the owner-operator of one of Europe's largest networks and a global cloud services platform which encompasses 12 data centers, 14 virtual data centers and 31 colocation centers, with connections to 195 add...
DevOps is often described as a combination of technology and culture. Without both, DevOps isn't complete. However, applying the culture to outdated technology is a recipe for disaster; as response times grow and connections between teams are delayed by technology, the culture will die. A Nutanix Enterprise Cloud has many benefits that provide the needed base for a true DevOps paradigm.
SYS-CON Events announced today that Juniper Networks (NYSE: JNPR), an industry leader in automated, scalable and secure networks, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Juniper Networks challenges the status quo with products, solutions and services that transform the economics of networking. The company co-innovates with customers and partners to deliver automated, scalable and secure network...
The age of Digital Disruption is evolving into the next era – Digital Cohesion, an age in which applications securely self-assemble and deliver predictive services that continuously adapt to user behavior. Information from devices, sensors and applications around us will drive services seamlessly across mobile and fixed devices/infrastructure. This evolution is happening now in software defined services and secure networking. Four key drivers – Performance, Economics, Interoperability and Trust ...
In his keynote at @ThingsExpo, Chris Matthieu, Director of IoT Engineering at Citrix and co-founder and CTO of Octoblu, focused on building an IoT platform and company. He provided a behind-the-scenes look at Octoblu’s platform, business, and pivots along the way (including the Citrix acquisition of Octoblu).
SYS-CON Events announced today that Hitachi Data Systems, a wholly owned subsidiary of Hitachi LTD., will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City. Hitachi Data Systems (HDS) will be featuring the Hitachi Content Platform (HCP) portfolio. This is the industry’s only offering that allows organizations to bring together object storage, file sync and share, cloud storage gateways, and sophisticated search an...
@GonzalezCarmen has been ranked the Number One Influencer and @ThingsExpo has been named the Number One Brand in the “M2M 2016: Top 100 Influencers and Brands” by Analytic. Onalytica analyzed tweets over the last 6 months mentioning the keywords M2M OR “Machine to Machine.” They then identified the top 100 most influential brands and individuals leading the discussion on Twitter.
The Internet of Things is clearly many things: data collection and analytics, wearables, Smart Grids and Smart Cities, the Industrial Internet, and more. Cool platforms like Arduino, Raspberry Pi, Intel's Galileo and Edison, and a diverse world of sensors are making the IoT a great toy box for developers in all these areas. In this Power Panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists discussed what things are the most important, which will have the most profound e...
@ThingsExpo has been named the Most Influential ‘Smart Cities - IIoT' Account and @BigDataExpo has been named fourteenth by Right Relevance (RR), which provides curated information and intelligence on approximately 50,000 topics. In addition, Right Relevance provides an Insights offering that combines the above Topics and Influencers information with real time conversations to provide actionable intelligence with visualizations to enable decision making. The Insights service is applicable to eve...