Unit testing, integration testing and system testing essentials

The difference between unit testing and integration testing:

Unit tests differ from test objects in comparison to integration tests:

? The tested object of integration testing is a combination of units, where different modules are often assigned to different personnel to develop. Integration testing focuses on interfaces and mates between different unit modules

The test object of the unit test is the unit that implements the specific function under these modules, which is generally the design content described in the corresponding detailed design. Unit testing focuses on whether the logical structure and function are correct within each specific unit module

Compared with system testing, unit testing focuses on discovering the logic errors of program design or implementation, which is basically the scope of white box testing.

?? Unit testing makes it easy to expose problems early, and to solve the problem, unit testing is an early test, so it is clear that a unit is produced by mistake.

?? Unit testing allows for simultaneous testing of multiple DUT units

system Test Definition:

? The system test is to test the software system which the Software project group undertakes to develop, the main purpose is to verify whether the software system satisfies the definition of the software Requirement specification.

System test object:

? Software Project Team undertakes the development of software system, is software project-level system

System Test Basis：

? Software Requirements Specification, various technical specifications

? The basis of system testing is by no means the software itself

design principles for System test cases:

System test cases should cover all test points of the software Requirements specification

System test cases should indicate actual input values and expected results

System test cases should take into account various input and output conditions and various boundary values

The design of system test cases should consider the feasibility of test execution

objects for integration testing:

module as the base unit

interface and synchronization mechanism between test modules

Test the correctness of global data between modules

Test if the sub-function is implemented

unit, integration, System test comparison:

Test Type	Object	Objective	Test basis	Test method
Unit Test	Level error inside the module	Eliminates logical and functional errors and flaws in local modules	Module Detail Design	A large number of white box test methods are used
Integration Testing	Assembly and invocation relationships between modules	Find out the program structure related to the software design, the module call relation, the interface problem between the modules	Software Overview Design	Combined with white box and black box test method, more Use black box method to construct test case
System Testing	The entire software system	A series of overall and validity tests for the entire system	Software Requirements Specification, etc.	Black box test

Integration Testing Features ---Complementary advantages :

? Unit testing is not exhaustive, the interface between the modules of the correctness of the content, the mutual invocation of the relationship between the design, helpless, can only rely on integration testing to ensure

　　Compared with the system test, because the integration test case is from the program structure, the goal, the pertinence is stronger, the test item discovers the problem the efficiency is higher, the localization question efficiency is also high

? It is easy to test to a special exception process that is difficult to simulate in a system test case, and from a purely theoretical point of view, integration testing can simulate all actual situations

　　Positioning problems faster, because the integration test has a strong repeatability, the characteristics of the test personnel transparent, found that the problem is easy to locate, so can effectively speed up progress, reduce hidden dangers

Unit testing, integration testing and system testing essentials