Native, Web and Hybrid - How related and different these apps are?

During discussion on mobile apps with a tester, one of the question was - "What is native app? What is the difference between hybrid app and native app?" Like one uses the mobile apps in and out almost all days on mobile devices, yet there is confusion in knowing what these apps are and the differences among them.  In this post, I do not share about advantages and disadvantages for the types of mobile apps, rather I share what I understand for what they are.  And, this should help to start learning on advantages and disadvantages if any.

Further knowing what is the technology stack being used for the native mobile app, web app and hybrid mobile app, a tester can design the tests better.  This helps to figure out the testability and from here one can get the idea which are good to automate and assess, and those which requires human skills to assess further and test.

Mobile web app and mobile device

I will walk through briefly on native mobile app and hybrid mobile app in this post. Before I do that, let me tell bit about web app with Responsive Web Design (RWD) for mobile devices.  Do you know any website that you use often? Open that site on your mobile device browser now and experience how it is rendered. Now, why not changing the orientation of your device and view it in portrait and landscape. What was your experience? Were you able to use it on mobile device? Did it render in same width and height as in desktop browser or it gut customized to your mobile device's screen?

Along with RWD, HTML5 and latest web technologies of JS with CSS, their exists frameworks to build web app for mobile which uses the nativity of mobile devices. They are evolving and exists, today.  One such example is Ionic framework.

While mobile OS extends the support of web view to display the web contents within the activity of an app, the above said web technologies and framework supports to build mobile web app.  With this the mobile web app can make use of device's hardware and sensor, as a native mobile app does.

This mobile web app is not available as an app in the Google's Play Store and Apple's App Store. However it can look like a mobile app in an experience but the implementation way differs. When a website can be rendered to mobile device's screen size, is it possible now to get a feel like not a browser based website though address bar is shown?  Frameworks available today to build the mobile web app will help to do so.

Some examples for the mobile web app are GMail, Flipkart, Amazon, and Facebook.



Native app and mobile device

Mobile app which is installed on mobile device and that can make use of hardware and sensor available on mobile device, is typically a native app.  This app is built for a particular mobile device's OS and platform.  With mobile device's few apps come pre-installed and user can still look for an app what she or he needs on Google's Play Store and Apple's Play Store.

A native app can access what it requires on mobile device provided it has the permission to do so. Now make a list of permissions you have seen which app asks you for installing and using it on the mobile device.

Some example for the native mobile app are Contacts, Message, Camera, Calendar, and the one which can be downloaded from the respective store of Google and Apple.

Note: In this context, I'm taking Google and Apple platforms as it is well known to most.



Hybrid app and mobile device

In above said, HTML5 and JS technologies have the major role in mobile web app. Now, the same can be used to build apps which can be installed on Android an iOS?

Technically the hybrid app will have HTML5 web app within a native wrapper which is supported by the mobile OS.  This mobile app is developed with HTML5, JS technologies and CSS, then compiled into native Android or native iOS or any other mobile OS using wrapper support.

Apache Cordova is one such mobile application development framework which  helps to wrap up an app that can run in WebView by having nativity extension to mobile device's (OS) platform. The plugins of Cordova can be used to access the device's hardware support. On knowing the word as Cordova, now if happened to explore further we will hear the words -- Phonegap, Titanium, Ionic, Xamarin etc. Knowing how they support to develop mobile application will help to understand better about the hybrid mobile app.

If the hybrid mobile app is also a kind of web app, then the HTML, CSS and JS files are stored in the app which will be installed on the device? Or, will it get from the server on launch of the web on a desktop browser?  This depends on how the hybrid app will be designed. If it is packaged into the .apk or .ipa file, then web APIs can be used send and received data.  If it is received from server then a layer around the WebView will have to built and web APIs will be still used.

The apps built in this sort are called hybrid because

• they are neither native apps as the rendering is on via WebViews instead of platform's UI framework
• they are neither web apps because they are packaged as an app for distribution across platforms using the platform nativity via its APIs

Have you used, GMail app on your phone by downloading it from store? Are you using Instagram, Facebook, Youtube, Maps apps on your mobile device on downloading it from store? Then that is an example of the hybrid app which combines the strength of native app and mobile web app together.

So whats the point

To end this post, if asked what is best i.e. whether native app or hybrid app, it depends on context and what is trying to be solved with negotiation.  Both helps to accomplish the needs of app developing organization, programmer, tester and user.  While each have they their own strength and weakness, it is the choice to be made by people who builds for whom.  In this post, I have not shared the advantages and disadvantages of it.

Now starts the fun of exploration around testing and automation.  How to test the apps built in hybrid way? What are the level of isolation I can identify so that I can layer it out layer by layer and test? Where to start if it is getting packaged into nativity of the platform on mobile OS?

If you are doing it or figured it out, pull me to pair with you and test together. Let us do it!

The Testability and a Tester

In one of the recent discussion with fellow testers, the topic was "testability".  While fellow testers asked, "what is testability?", I had a question which I shared in the discussion -- "What is codability?".


Codability and Testability

I see both of these are inter related.  If it is codable then it is testable to a degree.  What is that degree? That's the question of interest.  But, what is that one will accomplish by knowing the order of degree, here?  This forms the base in having the curiosity or wish to know about testability.

I have a product's feature which I have to implement. The feature has cases which I need to handle in run time for different situations which a user can encounter. Well, I can code for situations which I can think and which is of priority from point view of using the product. Then for other situations which I'm not seeing or not thought off, will it be a hit for my product?  What is the complexity level of the code I'm writing for this feature and what are the risks that are subtle in code I have written? The written code will always have the risk that is tied along with it.

Now, can I tell that testability is influenced by multiple factors and not just on the basis of the test identified? Well, after knowing this, it is essential to understand -- "testability is the easiness at which I can test the system in a given situation.".


Factors influencing testability

The few factors which will potentially influence the order of  easiness -- in learning the test challenge, identifying the test, approaching the test and executing it, are as below:

• The testing skills of a tester
• The programming skills of a tester
• The technology skills of a tester
• The experience of a tester in testing such systems
• What is know by tester about the product -- purpose of product; people who are building the product; people who will use or who are using the product; the features and functionality of product; technology of the product; code written for the product; how the product is built with limitations from business team; information available about the product; process, practice and culture followed by teams in building product; availability of the system and its present state
• Time available for system development
• Time available for testing
• The level or order to which the testability aid is built and can be provided in system to test, and the complexity or simplicity level of same
• Measures taken to improvise and include testability aiding stuffs in system
• Existing tools or utilities for testing the product or code, or to build one such utilities
• The freedom to tester and testing to control and guide the testing activity
• Information expected out of testing and priority of it
• Relationship with fellow testers, fellow programmers, business teams and any other who are involved and interested in the system being programmed and tested
• The audience interested in test report or outcome of testing and their expectation

Testability and Test Coverage

The test coverage accomplished by a tester in given context is relational to the skills set of tester and the testability factors of the system and environment.

While I have understood this, I tried to learn the scale of testability keeping the test coverage as base. Here is what I have observed for now.

By keeping the test coverage as a base scale might mislead me to learn what I can accomplish in coverage. Because, the testability might be available and easy one for me to accomplish the 10th level of coverage with my skills and other influencing factors of testability. But to cover and accomplish the first three levels can be not the easy one given my skills and other influencing factors of testability. The vice versa is also possible.  Here, I can take longer time to learn and know how could I have cut short and still accomplish the same coverage given the testability level to me in a context, if I had learned about the complexity level of of it. While I reach to a intended level of coverage, I would have done the moves which does not favor business timeline, learned from them and repeated few stuffs.  This is not wrong but I have consumed time which I could have invested in testing to accomplish much more coverage.  The same is represented in below image.

Keeping the test coverage in base and assessing the testability on vertical scale marking the breadth and width of coverage spread out in parallel which  I want accomplish or what I can accomplish, here is what I observe for now:

Understanding the test coverage I want to reach by my testing and automation, so I provide the information expected is a challenge each time.  The reason for simple to quote for first is the 'testability' for that coverage mark.  Once I get an idea of what is the skills that I need to build and use in such situations, it will help me to make strategic decisions in testing execution and its management.  The is very important as per me from point of view testing strategic base.  This is helping me and allows me to test the perceived level of testability itself for marked coverage boundary or milestones.

This base of strategic thinking in learning and identifying the testability can be used in timelines of a project. Not just during the execution of testing, also in pre-execution and post-execution, it can be used. It gives an idea of how the tester has to be equipped in changing needs of testing and engineering. For me this is working in context where I'm exposed and in few cases I had to add few vectors along with test coverage such as technology and programming factors specific. I'm experimenting this in varied projects having different technology and skill challenges.


Visibility out of testability

With this, for now I see,

• Testability is related with codability, programmer, tester, environment, process, people, situation, priorities
• Codability gives the first hint on testability and skills needed to test the same.
• Testability influences the Test Coverage
• Testability influences the time taken by a tester to test the system in a given context
• Like codability requires the skills of a programmer, testability requires skills of a tester

Note: Automation when leveraged with testability, wonders can be done via automation in assisting the testing.