Advantages of Top-Down Integration in Software Engineering

Unit Testing = Tests small program units or modules of a software system Integration Testing = Tests the different components of a software application together as a single unit Performance Testing = Ensures proper response times and system utilization SDLC = Defines the concept of Integration Testing and its position within

Unit Testing = Fully automated, easy to develop using a framework such as Jest Integration Testing = Tests modules working in combination, can be paired with Performance Testing at an early stage Unit Test vs Integration Test = Individual program units, such as procedures, functions, methods in isolation vs Modules are assembled to construct a larger subsystem and tested

Unit Testing = Individual program units, such as procedures, functions, methods in isolation Integration Testing = Modules are assembled to construct a larger subsystem and tested

<p>Top-Down Integration = Isolation of interface errors becomes easier because of the incremental nature of the integration Bottom-Up Integration = A new test driver is used</p> Signup and view all the answers

<p>Top-Down Integration = Test case selection and stub design become increasingly difficult when stubs lie far away from the top-level module Bottom-Up Integration = More modules such as B and D are integrated</p> Signup and view all the answers

<p>Top-Down Integration = Isolation of interface errors becomes easier Bottom-Up Integration = The test driver mimics module C to integrate E, F, and G in a limited way</p> Signup and view all the answers

<p>Integration Testing = Aims to discover defects that may arise when modules are integrated and must interact with each other System Integration Testing (SIT) = Objective is to build a 'working' version of the system Intra-system Testing = Low-level integration testing with the objective of combining the modules together to build a cohesive system Pairwise Testing = Only two interconnected systems in an overall system are tested at a time</p> Signup and view all the answers

<p>Incremental = Integration testing is conducted as a series of test cycles with additional modules integrated with each cycle Top-down = Starts with high-level modules and gradually incorporates lower-level modules using stubs Bottom-up = Involves testing the lowest level components first, then gradually testing higher level components Big-bang = All or most of the modules are integrated together and tested at one go</p> Signup and view all the answers

<p>First Phase = Integrate modules A and B using stubs C' and D' Second Phase = Replace stub D' with its actual instance D and perform interface and regression tests Third Phase = Replace stub C<code> with the actual module C, and incorporate new stubs E</code>, F<code>, and G</code> Final Phase = Perform tests on the interface between A and C and on the combined modules A, B, and D in the presence of C</p> Signup and view all the answers

<p>Fast Testing Process = The testing process is relatively quick High Code Coverage = Large portions of the system's code are tested Efficient Detection of System-Level Issues = An efficient method of detecting issues that occur when the system is functioning as a whole Early Bug Detection = Bugs can be detected early in the development process</p> Signup and view all the answers

<p>Bottom-Up Integration Testing = Discovery of major faults are detected towards the end of the integration process Big Bang Integration Testing = If a bug arises then the integrated modules must be detached in order to find the cause of the bug Sandwich Integration Testing = Does not test the individual subsystems on the target layer thoroughly before integration</p> Signup and view all the answers

<p>Bottom-Up Integration Testing = If the low-level modules and their combined functions are often invoked by other modules, then it is more useful to test them first Big Bang Integration Testing = Big Bang testing has the advantage that everything is finished before integration testing starts Sandwich Integration Testing = Top and bottom layer tests can be done in parallel</p> Signup and view all the answers

<p>Interface integrity = Internal and external interfaces are tested as each module is integrated Functional validity = Tests to uncover functional errors in each module after it is integrated End-to-end validity = Tests are designed to ensure that a completely integrated system works together from end-to-end Pairwise validity = Tests are designed to ensure that any two systems work properly when connected by a network</p> Signup and view all the answers

<p>Bottom-Up Integration Testing = The test driver is replaced with module A and further tests are performed Big Bang Integration Testing = First, all the modules are individually tested with unit tests all those modules are put together to construct the entire system, which is tested as a whole Sandwich Integration Testing = In this approach a system is integrated using a mix of top-down, bottom-up, and big-bang approaches</p> Signup and view all the answers