Lec.unit testing control flow

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UNIT TESTING - Complexity

Reference:

+ Software Testing Course @ Lonsdale System

+Structured Testing: A Testing Methodology Using the Cyclomatic Complexity Metric

@ Arthur: H. Watson + Thomas J. McCabe

HCMUNS – FIT – SE Dept - ST Course

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Control flow graphs

Cyclomatic complexity can be used for 2 purposes:

As a defect prevention technique

To determine the number of structural test cases that will execute all of independent paths through a program

HCMUNS – FIT – SE Dept - ST Course

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Control flow graph

HCMUNS – FIT – SE Dept - ST Course

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Control flow graph

HCMUNS – FIT – SE Dept - ST Course

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Cyclomatic complexity

Complexity = number of edges –number of nodes + 2

Sequence = 1-2+2 =1

If … then ... Else = (2-2+2) = 2

Repeat … until = (3-3+2) = 2

While do … end = (3-3+2) = 2

Case = (7-5+2) = 4

HCMUNS – FIT – SE Dept - ST Course

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HCMUNS – FIT – SE Dept - ST Course

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HCMUNS – FIT – SE Dept - ST Course

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Complexity = 13 -10 + 2=5

HCMUNS – FIT – SE Dept - ST Course

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Comlexity for AND & OR

Complexity = (9-7+2) = 4

HCMUNS – FIT – SE Dept - ST Course

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HCMUNS – FIT – SE Dept - ST Course

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HCMUNS – FIT – SE Dept - ST Course

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Exercise

HCMUNS – FIT – SE Dept - ST Course

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Exercise

HCMUNS – FIT – SE Dept - ST Course

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HCMUNS – FIT – SE Dept - ST Course

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HCMUNS – FIT – SE Dept - ST Course

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Alternative Approaches to Counting Complexity

Too simple

Complexity = number of decision predicates + 1

Let check examples again !