In
software engineering
Software engineering is a branch of both computer science and engineering focused on designing, developing, testing, and maintaining Application software, software applications. It involves applying engineering design process, engineering principl ...
, a test case is a specification of the inputs, execution conditions, testing procedure, and expected results that define a single test to be executed to achieve a particular
software testing
Software testing is the act of checking whether software satisfies expectations.
Software testing can provide objective, independent information about the Quality (business), quality of software and the risk of its failure to a User (computin ...
objective, such as to exercise a particular program path or to verify compliance with a specific requirement. Test cases underlie testing that is methodical rather than haphazard. A
battery of test cases can be built to produce the desired coverage of the software being tested. Formally defined test cases allow the same tests to be run repeatedly against successive versions of the software, allowing for effective and consistent
regression testing
Regression testing (rarely, ''non-regression testing'') is re-running functional and non-functional tests to ensure that previously developed and tested software still performs as expected after a change. If not, that would be called a '' regr ...
.
Formal test cases
In order to fully test that all the requirements of an application are met, there must be at least two test cases for each requirement: one positive test and one negative test. If a requirement has sub-requirements, each sub-requirement must have at least two test cases. Keeping track of the link between the requirement and the test is frequently done using a
traceability matrix. Written test cases should include a description of the functionality to be tested, and the preparation required to ensure that the test can be conducted.
A formal written test case is characterized by a known input and by an expected output, which is worked out before the test is executed. The known input should test a
precondition
In computer programming, a precondition is a condition or predicate that must always be true just prior to the execution of some section of code or before an operation in a formal specification.
If a precondition is violated, the effect of the ...
and the expected output should test a
postcondition In computer programming, a postcondition is a condition or predicate that must always be true just after the execution of some section of code or after an operation in a formal specification. Postconditions are sometimes tested using assertions w ...
.
Informal test cases
For applications or systems without formal requirements, test cases can be written based on the accepted normal operation of programs of a similar class. In some schools of testing, test cases are not written at all but the activities and results are reported after the tests have been run.
In
scenario testing, hypothetical stories are used to help the tester think through a complex problem or system. These scenarios are usually not written down in any detail. They can be as simple as a diagram for a testing environment or they could be a description written in prose. The ideal scenario test is a story that is motivating, credible, complex, and easy to evaluate. They are usually different from test cases in that test cases are single steps while scenarios cover a number of steps of the key.
Typical written test case format
A test case usually contains a single step or a sequence of steps to test the correct behavior/functionality and features of an application. An expected result or expected outcome is usually given.
Additional information that may be included:
*Test case ID - A unique identifier for the test case.
*Description/summary - The test case objective.
*Test steps - The exact steps to perform.
*Expected result - The expected outcome and how to determine whether it has been realized.
*Actual result
*Pre-requisites - Conditions that must exist or preparation required before test execution.
*Test category
*Author - name of the tester.
*Automation - whether this test case is automated or not and, if so, how.
*Pass/fail
*Remarks
Larger test cases may also contain prerequisite states or steps, and descriptions.
A written test case should also contain a place for the actual result.
These steps can be stored in a word processor document, spreadsheet, database or other common repository.
In a database system, you may also be able to see past test results and who generated the results and the system configuration used to generate those results. These past results would usually be stored in a separate table.
Test suite
In software development, a test suite, less commonly known as a validation suite, is a collection of test cases that are intended to be used to test a software program to show that it has some specified set of behaviors. A test suite often conta ...
s often also contain
* Test summary
* Configuration
Besides a description of the functionality to be tested, and the preparation required to ensure that the test can be conducted, the most time-consuming part in the test case is creating the tests and modifying them when the system changes.
Under special circumstances, there could be a need to run the test, produce results, and then a team of experts would evaluate if the results can be considered as a pass. This happens often on new products' performance number determination. The first test is taken as the base line for subsequent test and product release cycles.
Acceptance tests, which use a variation of a written test case, are commonly performed by a group of
end-user
In product development, an end user (sometimes end-user) is a person who ultimately uses or is intended to ultimately use a product. The end user stands in contrast to users who support or maintain the product, such as sysops, system administrato ...
s or clients of the system to ensure the developed system meets the requirements specified or the contract. User acceptance tests are differentiated by the inclusion of
happy path or positive test cases to the almost complete exclusion of negative test cases.
See also
*
Classification Tree Method
References
External links
Software Test Case EngineeringBy Ajay Bhagwat
{{Software engineering
Case
Case or CASE may refer to:
Instances
* Instantiation (disambiguation), a realization of a concept, theme, or design
* Special case, an instance that differs in a certain way from others of the type
Containers
* Case (goods), a package of relate ...