Software testing principles techniques and tools pdf free download

Acceptance Testing Chapter Here are eight tips that can magically transform homework from a super-struggle to some serious fun! Lois lives at 31 Spooner Street with her family and also. We are also looking: Please re-enter recipient e-mail address es. User manual and prjnciples. Find and save ideas about Haircuts for wavy hair on Pinterest.

Add 3 Items to Cart. Security in Computing 4th Edition 4. Your efforts will be much appreciated and surely paid off when the time comes for you to enter this rapidly developing software testing principles techniques and tools m.

A little boy puts all his scientific knowledge to use, trying to work out how to go faster than the speed of light and make time go backwards. Many governments in the world spend large amounts of m. Publishing quality and relevant content you curate on a regular basis will develop your online visibility and traffic. One can define several small variations on the loop boundary criterion. For example, we might excuse from consideration loops that are always ex- ecuted a definite number of times e.

In practice the last part of the 9 Section It is easy enough to define such a coverage criterion for loops, but how can we justify it? Why should we believe that these three cases — zero times through, once through, and several times through — will be more effective in revealing faults than, say, requiring an even and an odd number of iter- ations?

The intuition is that the loop boundary coverage criteria reflect a deeper structure in the design of a program. This can be seen by their re- lation to the reasoning we would apply if we were trying to formally verify the correctness of the loop.

The basis case of the proof would show that the loop is executed zero times only when its postcondition what should be true immediately following the loop is already true. We would also show that an invariant condition is established on entry to the loop, that each iteration of the loop maintains this invariant condition, and that the invariant together with the negation of the loop test i.

The loop boundary criterion does not require us to explicitly state the precondition, invariant, and postcondition, but it forces us to exercise es- sentially the same cases that we would analyze in a proof. There are additional path-oriented coverage criteria that do not explicitly consider loops. Among these are criteria that consider paths up to a fixed length.

We have stated that coverage of individual LCSAJs is almost, but not quite, equivalent to branch coverage. How can they differ? The number of paths to be exercised can also be limited by identifying a subset that can be combined in a manner to be described shortly to form all the others.

To be more precise, the sense in which a basis set of paths can be com- bined to form other paths is to consider each path as a vector of counts in- dicating how many times each edge in the control flow graph was traversed, e. The basis set is combined by adding or subtracting these vectors and not, as one might intuitively expect, by concatenating paths.

Cyclomatic testing does not require that any particular basis set is covered. Rather, it counts the number of independent paths that have actually been covered i. They are not well suited to integration testing or sys- tem testing. It is difficult to steer fine-grained control flow decisions of a unit when it is one small part of a larger system, and the cost of achieving fine- grained coverage for a system or major component is seldom justifiable.

Usu- ally it is more appropriate to choose a coverage granularity commensurate with the granularity of testing. Moreover, if unit testing has been effective, then faults that remain to be found in integration testing will be primarily interface faults, and testing effort should focus on interfaces between units rather than their internal details. In some programming languages FORTRAN, for example , a single pro- cedure may have multiple entry points, and one would want to test invoca- tion through each of the entry points.

More common are procedures with multiple exit points. For example, the code of Figure Each of these ing would have been exercised already if even the simplest statement coverage criterion were satisfied during unit testing, but perhaps only in the context of a simple test driver; testing in the real context could reveal interface faults that were previously undetected.

Exercising all the entry points of a procedure is not the same as exercising all the calls. For example, procedure A may call procedure C from two distinct points, and procedure B may also call procedure C. In this case, coverage of calls of C means exercising all three of the points of calls. Commonly available testing tools can measure coverage of entry and exit points. The search function in Figure It was called at only point, from one other C function in the same unit.

Coverage of calls requires exercis- ing each statement in which the parser and scanner access the symbol table, but this would almost certainly be satisfied by a set of test cases exercising each production in the grammar accepted by the parser.

When procedures maintain internal state local variables that persist from call to call , or when they modify global state, then properties of interfaces may only be revealed by sequences of several calls. In object-oriented pro- gramming, local state is manipulated by procedures called methods, and sys- tematic testing necessarily concerns sequences of method calls on the same object. While these complications may arise even in conventional procedural programs e. Not surprisingly, then, approaches to systematically exercising sequences of pro- cedure calls are beginning to emerge mainly in the field of object-oriented testing, and we therefore cover them in Chapter This is primarily exception handling.

The relations among these criteria are illustrated in Figure The search function was analogous in this case to a private internal method of a class. The hierarchy can be roughly divided into a part that relates requirements for covering program paths, and another part that relates requirements for covering combinations of conditions in branch decisions.

The two parts come together at branch coverage. Above branch coverage, path-oriented criteria and condition-oriented criteria are generally separate, because there is con- siderable cost and little apparent benefit in combining them.

Statement cov- erage is at the bottom of the subsumes hierarchy for systematic coverage of control flow. Applying any of the structural coverage criteria, therefore, im- plies at least executing all the program statements. This is true even for the statement coverage criterion, weak as it is. Unreachable statements can occur as a result of defensive programming e. Stronger coverage criteria tend to require coverage of more infeasible ele- ments. For example, in discussing multiple condition coverage, we implicitly assumed that basic conditions were independent and could therefore occur in any combination.

In reality, basic conditions may be comparisons or other relational expressions and may be interdependent in ways that make certain combinations infeasible.

Fortunately, short- circuit evaluation rules ensure that the combination hFalse; Falsei is not re- quired for multiple condition coverage of this particular expression in a C or Java program. In the trivial case where these if statements occur together, the problem is both easy to understand and to avoid by placing the second if within an else clause , but essentially the same interdependence can occur when the decisions are separated by other code.

The other main option is requiring justification of each element left un- covered. Explaining why each element is uncovered has the salutory effect of distinguishing between defensive coding and sloppy coding or maintenance, and may also motivate simpler coding styles. However, it is more expensive because it requires manual inspection and understanding of each element left uncovered and is unlikely to be cost-effective for criteria that impose test obligations for large numbers of infeasible paths.

This problem, even more than the large number of test cases that may be required, leads us to conclude that stringent path-oriented coverage criteria are seldom useful. Structural coverage criteria are not incremental in this sense. Even a small change has an unpredictable effect on coverage. If a set of test cases has achieved a certain level of coverage before the change, it is impossible to determine what level of coverage the same test set will produce after the program change.

This implies that measurement of structural coverage in quickly evolving software cannot be used in the same way it might for a stable unit. For example, during development of a unit, structural coverage might be used to identify untested elements, but measures of satisfaction of cover- age would be of little value.

When the unit is delivered to an independent test group, structural coverage could be more profitably used as an indicator of the thoroughness of testing by the developers, or as a termination condition.

Open Research Issues Devising and comparing structural criteria was a hot topic in the 80s. It is no longer an active research area for imperative programming, but new pro- gramming paradigms or design techniques present new challanges. Poly- morphism, dynamic binding, object oriented and distributed code open new problems and require new techniques, as discussed in other chapters.

Appli- cability of structural criteria to architectural design descriptions is still under investigation. Usefulness of structural criteria for implicit control flow has been addressed only recently. Early testing research, including research on structural coverage criteria, was concerned largely with improving the fault-detection effectiveness of test- ing. Today, the most pressing issues are cost and schedule.

Alternatively, for many applications it may be more appropriate to gather evidence of feasibility from actual product use; this is called residual test coverage monitoring and is a topic of current re- search. The incrementality problem described above is particularly impor- tant in the context of rapid cycles of product development and change, and will surely be a topic of further testing research for the next several years.

The end user's viewpoint is obviously vital to early phases cost less as compared to later phases. For the success of the software, but it is not all that matters as example, if a problem in the requirements is found after all needs cannot be fulfilled because of technical, releasing the product, then it would cost 10— times budgetary or scheduling limitations.

What was tested, and how it was tested, are needed as part of an ongoing testing process. Such things serve as a means to eliminate duplicate testing effort [8]. Test plans should be clear enough to be re-read and comprehended. We should agree on the common established documentation methods to Cost avoid the chaos and to make documentation more useful in error prevention.

We should know what we are doing, what are we targeting, what will be the possible outcome. Coverage criteria Reqs Design Code Test should expose all defects of a decided nature and priority. Implementation Also, afterward surfacing errors should be categorized as Time to which section in the coverage it would have occurred, Fig. Having clean insight into the Testing is done differently in different contexts. Testing process allows us to better estimate costs and to better should be appropriate and different for different points of direct the overall development.

For example, a safety-critical software is tested differently from an e-commerce site. Even a system III. Even the objectives of Testing Principles offer general guidelines common for testing differ at different point in software development all testing which assists us in performing testing cycle.

For example, the objective of unit and integration effectively and efficiently. Principles for software testing testing is to ensure that code implemented the design are: properly. In system testing the objective is to ensure the 3. Type of Testing is the process of executing a program with the testing approach that will be used depends on a number of intent of finding errors [7].

Our objective should be to factors, including the type of system, regulatory demonstrate that a program has errors, and then only true standards, user requirements, level and type of risk, test value of testing can be accomplished. We should expose objective documentation available, knowledge of the failures as many as possible to make testing process testers, time and budget, development life cycle.

Test plan of the developers. Testing at coverage criteria. Tests at this level are based on other quality characteristics such as portability, a system specification. Development staff shall be maintainability and usability.

Acceptance Testing is usually 3. Release Testing is Complete and precise requirements are crucial for performed by Quality Manager. User Requirements should be well involved at different levels of software testing.

Testing should be performed against those user requirements. The test case scenarios shall be written and scripted before testing Release testing Quality Manager begins. If you do not understand the user requirements and architecture of the product you are testing, then you will not be able to design test cases which will reveal more errors in short amount of time.

A necessary part of test documentation is the specification of expected results, Specialised even if providing such results is impractical [7]. Many errors are discovered when a program under test is used in some new and unexpected way and invalid input conditions seem to have higher error detection yield than do test Testing Levels Performed by cases for valid input conditions [9]. Choose test inputs that possibly will uncover maximum faults by triggering Fig.