Fall, 2006SW Eng Standalone Progs, Univ of Colorado Boulder 1 Wk 11 Glass Box Testing, Flow Graphs, Test Coverage SW Engineering of Standalone Programs.

Fall, 2006 SW Eng Standalone Progs, Univ of Colorado Boulder

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Wk 11 Glass Box Testing, Flow Graphs, Test Coverage

SW Engineering of Standalone Programs


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Basis set for statement coverage testing

• Draw the flow graph• Count the bounded regions including the “outside

region”– N is the number of linearly independent paths through the

program control structure

– A linearly independent path includes one node of the control flow graph not contained in any other

– Create a basis set of linearly independent paths

• Prepare test cases to force execution of each path in the basis set.

• Execution of these test cases yields ______ coverage


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Flow Graph:McCabe’s is25


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Flow Graph Revelations


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Complexity impact


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Uses of Test Coverage Measurement

• Measure test suite completeness• Identify risk areas

– Combine execution counts with complexity– Understand complex code segments that are

frequently executed– Understand criticality

• Assist in creating new test cases • Assist in manual detection of faults• Prioritize test cases for regression tests


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Some More Test Coverage terms


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Test Coverage MeasuresCompleteness of Test Suite


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Test Coverage MeasurementMinimize and select regression tests 377 Total Tests

Blocks Decisions P-uses All-uses

75% 65% 38% 44%

160 Total Tests


75% 65% 38% 44% 18 Total Tests


62% 52% 30% 37%

42% of the original tests provide identical coverage

5% of original tests provide 85% of original coverage


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Unit Test Coverage vsSystem Test Errors


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System Test Observed & Expected Failures


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System Test Failure Rate over Active Hrs


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System Test Case Completion Graph


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HW 7 start of codegetop(s, lim) /*get next operator or operand */

char all;

int lim;

{

int i, c;

while ((c = getch ( ) ) == ‘ ‘|| c == ‘\t’ || c == ‘\n’)

;

if (c ! = ‘.’ && (c<‘0’ || c>’9’))

return (c);

s[0] = c;

for (i=1; (c=getchar()) >= ‘0’ && c <=‘9’; i++)

if (i < lim)

s[i] = c;

if ...


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Inspections


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What are inspections?

• Means of verifying work products

• Manual examination technique

• One piece at a time

• Small group of peers – at least 4


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Purpose

• Verification of a work product against– established criteria– product specifications


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How performed?

• Planning

• Overview

• Preparation

• Meeting

• Re-work

• Follow up


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Roles of participants

• Author

• Moderator

• Reader

• Recorder

• Inspector


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The meeting

• Each participant reports preparation time• Reader paraphrases

– Pace should be effective

– Not too slow, not too fast

• Inspectors look, listen, and think simultaneously• Author and inspectors speak up if they disagree with

reader’s paraphrase – need to decide which is correct. If Reader, Recorder notes location & brief description of issue

• Moderator can adjust pace and “atmosphere”


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End of meeting

• Recorder’s list goes to author

• After rework, at a minimum, author reviews changes with one inspector.

• Better – inspect the changed item


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Benefits

• Errors found at faster rate

• Errors found early are cheaper to fix

• Cross-training

• Learn good and bad techniques by seeing them, e.g. coding techniques


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A Word about Extreme Programming

• My personal view of extreme programming is that Beck & Cunningham managed to incorporate many effective software engineering tasks into short iterations with high feedback.

• One example: pair programming is ...

Fall, 2006SW Eng Standalone Progs, Univ of Colorado Boulder 1 Wk 11 Glass Box Testing, Flow Graphs, Test Coverage SW Engineering of Standalone Programs.

Documents

sw eng standalone progs

univ of colorado boulder

test coverage terms

new test cases

original coverage

system test failure

complexity impact slide

identical coverage