chapter 3: static testing Flashcards
(45 cards)
Testing that involves the execution of the test item
Dynamic testing
A condition that deviates from expectation.
Anomaly
A type of review that follows a defined process with a formally documented output.
Formal review
- A type of review that does not follow a defined process and has no formally documented output
Informal review
A type of formal review that uses defined team roles and measurement to identify defects in a work product, and improve the review process and the software development process.
Inspection
A type of STATIC TESTING in which a work product or process is evaluated by one or more individuals to detect defects or to provide improvements.
Review
The process of evaluating a component or system without executing it, based on its form, structure, content, or documentation
Static analysis
Testing that does not involve the execution of a test item.
Static testing
- A formal review by technical experts that examine the quality of a work product and identify discrepancies (a lack of similarity between two or more facts) from specifications and standards. See also: peer review
Technical review
A type of review in which an author leads members of the review through a work product and the members ask questions and make comments about possible issues. Reference: After ISO 20246 Synonyms: structured walkthrough See also: peer review
Walkthrough
static testing objectives
-improving quality
-detecting defects
-assessing characteristics like readability, completeness, correctness, testability and consistency.
Testers, business representatives and developers work together during example mappings, collaborative user story writing and backlog refinement sessions to ensure that user stories and related work products meet defined criteria,
the Definition of Ready
-Review techniques can be applied to
-ensure user stories are complete and understandable
- include testable acceptance criteria.
-By asking the right questions, testers explore, challenge and help improve the proposed user stories.
Almost any work product can be examined using static testing:
Examples:
requirement specification documents
source code
test plans
test cases
product backlog items
test charters (Documentation of the goal or objective for a test session.)
project documentation
contracts
models.
-Any work product that can be read and understood can be the subject of a review. However, for static analysis, work products need a structure against which they can be checked (e.g., models, code or text with a formal syntax).
-Work products that are not appropriate for static testing include
those that are difficult to interpret by human beings and that should not be analyzed by tools (e.g., 3rd party executable code due to legal reasons).
value of static testing
-Static testing can detect defects in the earliest phases of the SDLC, (principle of early testing)
identifies defects which cannot be detected by dynamic testing (e.g., unreachable code, design patterns not implemented as desired, defects in non-executable work products).
-provides the ability to evaluate the quality of, and to build confidence in work products
-By verifying the documented requirements, the stakeholders can also make sure that these requirements describe their actual needs.
-Communication will also be improved between the involved stakeholders. For this reason, it is recommended to involve a wide variety of stakeholders in static testing.
-Code defects can be detected using static analysis more efficiently than in dynamic testing, usually resulting in both fewer code defects and a lower overall development effort.
Differences between Static Testing and Dynamic Testing
-Static testing and dynamic testing practices complement each other.
-Similar because they support the detection of defects in work products
differences:
Static and dynamic testing (with analysis of failures) can both lead to the detection of defects, however there are some defect types that can only be found by either static or dynamic testing.
Static testing finds defects directly, while dynamic testing causes failures from which the associated defects are determined through subsequent analysis
Static testing may more easily detect defects that lay on paths through the code that are rarely executed or hard to reach using dynamic testing
Static testing can be applied to non-executable work products, while dynamic testing can only be applied to executable work products
Static testing can be used to measure quality characteristics that are not dependent on executing code (e.g., maintainability), while dynamic testing can be used to measure quality characteristics that are dependent on executing code (e.g., performance efficiency)
static testing code execution vs dynamic testing code execution
Static testing can be used to measure quality characteristics that are not dependent on executing code (e.g., MAINTAINBILITY ),
while dynamic testing can be used to measure quality characteristics that are dependent on executing code (e.g., PERFORMANCE EFFICIENCY)
Typical defects that are easier and/or cheaper to find through static testing:
Defects in requirements (e.g., inconsistencies, ambiguities, contradictions, omissions [omission is something that has been left out or excluded], inaccuracies, duplications)
Design defects (e.g., inefficient database structures, poor modularization)
Certain types of coding defects (e.g., variables with undefined values, undeclared variables, unreachable or duplicated code, excessive code complexity)
Deviations from standards (e.g., lack of adherence to naming conventions in coding standards)
Incorrect interface specifications (e.g., mismatched number, type or order of parameters)
Specific types of security vulnerabilities (e.g., buffer overflows)
Gaps or inaccuracies in test basis coverage (e.g., missing tests for an acceptance criterion)
can static and dynamic testing be applied to all test levels?
yes
-A failure to deliver what the stakeholder wants can result in
costly rework,
missed deadlines,
blame games,
and might even lead to complete project failure.
-If the required review is more formal,
then more of the tasks described for the different activities will be needed.
work products with review
The size of many work products makes them too large to be covered by a single review.
The review process may be invoked a couple of times to complete the review for the entire work product.
The activities in the review process are:
Planning. During the planning phase, the scope of the review, which comprises the purpose, the work product to be reviewed, quality characteristics to be evaluated, areas to focus on, exit criteria, supporting information such as standards, effort and the timeframes for the review, shall be defined.
Review initiation. During review initiation, the goal is to make sure that everyone and everything involved is prepared to start the review. This includes making sure that every participant has access to the work product under review, understands their role and responsibilities and receives everything needed to perform the review.
Individual review. Every reviewer performs an individual review to assess the quality of the work product under review, and to identify anomalies, recommendations, and questions by applying one or more review techniques (e.g., checklist-based reviewing, scenario-based reviewing). The ISO/IEC 20246 standard provides more depth on different review techniques. The reviewers log all their identified anomalies, recommendations, and questions.
Communication and analysis. Since the anomalies identified during a review are not necessarily defects, all these anomalies need to be analyzed and discussed. For every anomaly, the decision should be made on its status, ownership and required actions. This is typically done in a review meeting, during which the participants also decide what the quality level of reviewed work product is and what follow-up actions are required. A follow-up review may be required to complete actions.
Fixing and reporting. For every defect, a defect report should be created so that corrective actions can be followed-up. Once the exit criteria are reached, the work product can be accepted. The review results are reported.
