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Published byDorthy Mason Modified over 9 years ago
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White Box Testing
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Path yang berbeda dalam modul software akan dibentuk oleh pilihan kondisional statement seperti IF-THEN-ELSE atau DO WHILE atau DO UNTIL atau REPEAT-UNTIL
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Dikembangkan oleh McCabe (1976) untuk mengukur kompleksitas program atau modul pada waktu yang sama sebagai jumlah maksimum independent path yang dibutuhkan untuk mencapai full line coverage pada program. Dasar ukuran adalah teori graf dan dihitung berdasarkan kesesuaian ke sifat program yang dicapture oleh program flow graph Independent path adalah setiap path pada program flow graph sedikitnya satu baris yang tidak dibentuk oleh independent path lain.
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20 times A B How many test cases ?
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0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 void main (void) { int a, b, c; int min, med, max; if (a>b) { max=a; min=b; } else { max=b; min=a; } if (c>max) {max=c;} else if (c<min) {min=c;} med=a+b+c-min-max; if (max>min+med) {printf("impossible triangle \n");} else if (max==min) {printf("equilateral triangle \n");} else if (max==med || med==min) {printf("isoceles triangle \n");} else if ( max *max == min*min+med*med) {printf("rightangled triangle\n");} else {printf("any triangle\n");} } v(G) = 25 - 19 + 2 = 8 8 Path = ?? 1 10 11 12 13 14 3 4 5 6 7 8 9 17 15 16 18 19 2 Example : if ( a > b and b > c) then max=a; else max = 100; end if ;
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V(G) = R V(G) = E – N +2 V(G) = P + 1 Keterangan V(G) = cyclometic complexity metric R = jumlah region dalam program flow graph Setiap area yang melingkungi graph disebut sebuah region E = Jumlah Edge (garis) N = Jumlah node P= Jumlah decision
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if... else... v(G)=2 if..... v(G)=2 while... v(G)=2 2 1 2 3 1 3 1 2 3 4
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b eg a c fd v(g)=10-7+2=5 This graph has 5 independent paths: C1abcbcg C2abefg C3adfg C4adefg C5abcg All the other paths are derived from the preceding 5 by linear combination example: abcbcbefg=C1+C1+C2-C5-C5
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1 2 4 7 8 3 65 Next, we derive the independent paths: Since V(G) = 4, there are four paths Path 1:1,2,3,6,7,8 Path 2:1,2,3,5,7,8 Path 3:1,2,4,7,8 Path 4:1,2,4,7,2,4…7,8 Finally, we derive test cases to exercise these paths, i.e. choose inputs that lead to traversing the paths
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Statement coverage Decision coverage Condition coverage Decision-condition coverage Multiple-condition coverage
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complete path testing is not a realistic goal for a program with loops.
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writing a single test case that traverses path ace. by setting A=2, B=0, and X=3 at point a, Every statement would be executed once (actually, X could be assigned any value).
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Unfortunately, this criterion is a rather poor one. Perhaps the first decision should be an or rather than an and Perhaps the second decision should have stated X>0 Also, there is a path through the program in which X goes unchanged (the path abd) the statement coverage criterion is so weak that it generally is useless.
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This criterion states that you must write enough test cases that each decision has a true and a false outcome at least once. each branch direction must be traversed at least once. Decision coverage usually can satisfy statement coverage.
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decision coverage requires that each decision have a true and a false outcome, and that each statement be executed at least once. has to be modified for programs that contain multiway decisions. Java programs containing select (case) statements,
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decision coverage can be met by two test cases covering paths ace and abd or, alternatively, acd and abe ▪ A = 3, B = 0, X = 3 ▪ A = 2, B = 1, and X = 1.
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stronger criterion than statement coverage, but it still is rather weak. there is only a 50 percent chance that we would explore the path where X is not changed (abd) only if we chose the former alternative ▪ ace and abd
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A criterion that is sometimes stronger than decision coverage is condition coverage. write enough test cases to ensure that each condition in a decision takes on all possible outcomes at least once. this does not always lead to the execution of each statement, an addition to the criterion is that each point of entry to the program or subroutine, as well as ON units, be invoked at least once.
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Figure 4.1 has four conditions: A>1, B=0, A=2, and X>1. enough test cases are needed to force the situations where A>1, A 0 are present at point a and where A=2, A<>2, X>1, and X<=1 are present at point b. ▪ 1. A=2, B=0, X=4 ace ▪ 2. A=1, B=1, X=1 abd
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Alternative 1. A=1, B=0, X=3 2. A=2, B=1, X=1 cover all condition outcomes, but they cover only two of the four decision outcomes. both of them cover path abe
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requires sufficient test cases that each condition in a decision takes on all possible outcomes at least once, Each decision takes on all possible outcomes at least once, and each point of entry is invoked at least once.
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A weakness with decision/condition coverage is that, although it may appear to exercise all outcomes of all conditions, it frequently does not because certain conditions mask other conditions.
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Figure 4.2 is the way a compiler would generate machine code A more thorough test coverage, appears to be the exercising of all possible outcomes of each primitive decision The two previous decision coverage test cases do not accomplish this; they fail to exercise the false outcome of decision H and the true outcome of decision K.
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This criterion requires that you write sufficient test cases that all possible combinations of condition outcomes in each decision, and all points of entry, are invoked at least once.
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It should be easy to see that a set of test cases satisfying the multiple condition criterion also satisfies the decision-coverage, condition coverage, and decision/condition-coverage criteria.
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These combinations to be tested do not necessarily imply that eight test cases are needed. In fact, they can be covered by four test cases. A=2, B=0, X=4 Covers 1, 5 A=2, B=1, X=1 Covers 2, 6 A=1, B=0, X=2 Covers 3, 7 A=1, B=1, X=1 Covers 4, 8
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The fact that there are four test cases and four distinct paths in Figure 4.1 is just coincidence. In fact, these four test cases do not cover every path; they miss the path acd.
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In the case of loops, the number of test cases required by the multiple-condition criterion is normally much less than the number of paths.
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