Black Box Test Techniques. Syntax Testing

by Nataliia Vasylyna | September 16, 2011 10:00 am

Introduction to black box testing to can find here[1].

Syntax Testing

Analysis
Syntax Testing uses such model of the formally defined syntax of the inputs to a component. The syntax is described as a number of rules each of which characterizes the probable means of production of a symbol in terms of sequences, iterations, or selections between symbols.

Test cases with valid and invalid syntax are designed from the formally defined syntax of the inputs to the component.

Supplementary rules can also be applied when appropriate:

• whenever an iteration is used, at least 2 options are derived, one with the minimum number of iterated symbols and the other with more than the minimum number of repetitions
• whenever a selection is used, an option is derived for each alternative by replacing the selection with that alternative

For every test case these should be clarified:

• the input to the component;
• the generic mutation used;
• the syntax element to which the mutation is applied;
• the expected result of the test case.

Test cases with invalid syntax should be designed as:

• a checklist of generic mutations should be documented which can be applied to rules in order to generate an invalid area of the input;
• this checklist should be applied to the syntax to identify particular mutations of the valid input;
• test cases should be designed to perform particular mutations.

A test case may exercise any number of options. For each test case these should be clarified:

• option exercised;
• the input to the component;
• the expected result of the test case.

Statement Testing

Design
Test cases should be designed to exercise feasible statements.

For each test case the these should be clarified:

• the input to the component
• identification of statement to be performed by the test case
• the expected result of the test case

Analysis
Statement testing uses such model of the source code which identifies statements as either feasible or non- feasible.

Random Testing

Design
Test cases should be chosen randomly from the input domain of the component according to the input distribution.

The input distribution which used for the test case suite should be recorded.

A test case should include:

• the input to the component
• the expected result of the test case

Analysis
Random Testing uses such model of the input domain of the component that characterizes the set of all probable input values. The input distribution which used in the generation of random input values should be based on the expected operational distribution of inputs. If it happens so that no information of operational distribution is accessible then a uniform input distribution should be used.

More about black box testing you can find here[2].

Related Posts:

• Black Box Test Techniques. Cause-Effect Graphing[3]
• Alpha Testing vs Beta Testing[4]
• ‘Rainbow’ Box Testing[5]

Source URL: https://blog.qatestlab.com/2011/09/16/black-box-test-techniques-syntax-testing/

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