The concept of shift testing implies that testing begins at the very initial stage of the software development life cycle. The aim of this testing is to reduce long test cycles, enhance quality or to reduce the possibility of defect detection at later stages. Shift left testing avoids delays, rework bring done to fix errors that may occur, by following the strategy of integrating the developed components, as and when they are delivered, in a realistic production-like test lab. If in case any of the component cannot be delivered within the prescribed time limit, then a virtual set up can be sought which emulates the behaviour of the real work environment, until the final product is released.
But why the term shift left? What relevance does left hold ? Shift left has derived its meaning from a model in software testing, in which integration testing lies on the right side of the model, which implies that integration testing is the next subsequent test after unit testing. But the concept of shift left testing has imbibed it in its own form by shifting it to the left side, that is, testing begins at early stage. The positive impact of shift testing can be seen in agile development, where there has been a noteworthy improvement in quality as the developers delivered code in pieces, that made the task of error detection simpler and quicker.
To categorise the various types of testing, we will take the V-model into consideration as that forms the basis of this model.
Ever wondered what would it be like , had the concept of shift left testing never taken place! Or the synonymous statement could be, what if we had considered opting for late testing? Then the situation would have been quite different. Let us have a look at the following few facts, that highlight the impact that our project can face due to late testing.
The focus of this testing is to enable detection of errors at an early stage, in order to save time and cost of fixing the defects. It relies on step by step integration of small pieces of code, therefore minimising the chances of errors. It improves efficiency and effectiveness of the software testing process.