Whitebox techniques - Decision Testing and Decision Coverage - prepare yourself for the ISTQB exam with TestCompetence.

1. Decision Testing and Decision Coverage
with
Prepare yourself for the ISTQB exam

2. Dictionary
branch: A basic block that can be selected for execution based on
a program construct in which one of two or more alternative
program paths is available, e.g. case, jump, go to, if-then- else.
branch coverage: The percentage of branches that have been
exercised by a test suite. 100% branch coverage implies both 100%
decision coverage and 100% statement coverage.
branch testing: A white box test design technique in which test
cases are designed to execute branches.
From „Standard glossary of terms used in Software Testing”
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3. Dictionary
decision: A program point at which the control flow has two or
more alternative routes. A node with two or more links to separate
branches.
decision coverage: The percentage of decision outcomes that
have been exercised by a test suite. 100% decision coverage
implies both 100% branch coverage and 100% statement coverage.
decision testing: A white box test design technique in which test
cases are designed to execute decision outcomes.
decision outcome: The result of a decision (which therefore
determines the branches to be taken).
From „Standard glossary of terms used in Software Testing”
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4. What is…?
Decision coverage, related to branch testing, is the
assessment of the percentage of decision outcomes
(e.g. the True and False options of an IF statement) that
have been exercised by a test case suite. Decision
testing derives test cases to execute specific decision
outcomes, normally to increase decision coverage.
Decision testing is a form of control flow testing as it
generates a specific flow of control through the decision
points. Decision coverage is stronger than statement
coverage: 100% decision coverage guarantees 100%
statement coverage, but not vice versa.
From „Certified Tester Foundation Level Syllabus (version 2011)”
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5. Rules!
100% branch coverage implies 100%
decision coverage.
Branch testing = arc testing = algorithm testing
From „Certified Tester Foundation Level Syllabus (version 2011)”
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6. Examples with sequential code
sep = az * wn;
csc = dvz + isc + d;
There are no decisions to
take.
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7. Examples with IF
IF (vz)
{
fuf = azh - e; In order to cover all
} decisions and branches,
ic = pcg + icn / n; you need
2 test cases.
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8. Examples with IF ELSE
IF (lfn)
{
j = ag + vy - f; In order to cover all
} decisions and branches,
ELSE you need
{ 2 test cases.
l = ar * hkh;
}
vgd = i * qla / p;
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9. Examples with SWITCH
SWITCH (i)
{
CASE 0: In order to cover all
krg = z - kz; decisions and branches,
break; you need
CASE 1: 2 test cases.
tob = zrc * cxd;
break;
}
rl = gs / dl * s;
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10. Examples with WHILE
uyn = -9;
WHILE (bo || uyn < -3)
{ In order to cover all
qx = q - ba / i; decisions and branches,
uyn++; you need
} 1 test case.
moa = 4;
WHILE (ei || moa > -3)
{
h = udi * cj;
moa--;
}
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11. Examples with FOR
FOR (a = 5; a > -5; a--)
{
b = c + 1; In order to cover all
} decisions and branches,
you need
1 test case.
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12. More examples
IF (u)
{
IF (s)
{ In order to cover all
l = el * n * iq; decisions and branches,
} you need
ELSE 4 test cases.
{
fz = ga / ca + vd;
}
}
ELSE
{
IF (upd)
{
w = tvo / x + y;
}
ELSE
{
grm = neq + ads;
}
}
e = lcu + b;
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13. More examples
h = -4;
WHILE (ww || h < 6)
{ In order to cover all
zx = 1; decisions and branches,
WHILE (iya || zx > -9) you need
{ 1 test cases.
hm = am * x;
zx--;
}
h++;
}
ye = 7;
WHILE (iob || ye > 2)
{
boi = nk - u + ijy;
ye--;
}
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14. More examples
vc = 8;
WHILE (xa || vc > -2)
{ In order to cover all
FOR (i = 0; i < 2; i++) decisions and branches,
{ you need
FOR (qgn = 1; qgn > -2; qgn--) 1 test cases.
{
p = u * ufi;
}
}
vc--;
}
FOR (ij = -2; ij > -12; ij--)
{
pqr = n + fdq / jx;
}
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15. More examples with…
TestCompetence allows you to generate sample pseudocode to pracitse whitebox
techniques including statement coverage…
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16. More examples with…
TestCompetence allows you to generate sample pseudocode to pracitse whitebox
techniques including decision coverage…
Choose the
maximum
number of
Choose the instructions
level of per level.
nested
statements. Choose the
type of
Choose the coverage
type of from:
statement. statement,
decision,
codition,
multiple
condition,
GENERATE and modified
your exercise. condition.
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17. More examples with…
You get pseudocode and sample answers just like during a regular ISTQB exam.
Choose the right answer.
Pseudocode
Choose
an answer.
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18. More examples with…
You get pseudocode and sample answers just like during a regular ISTQB exam.
Choose the right answer.
Pseudocode
Your answer
Right answer
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19. How to get it…
Visit TestCompetence.com and get one for only…
EURO / USD
Unlimited number of exercises during 24 hours!
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20. Check also examples for…
• Statement testing and coverage >>
• Condition testing and coverage >>
• Multiple condition testing and
coverage >>
• Modified condition decision
combination (MC/CD) coverage >>
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