diff options
Diffstat (limited to 'usth/ICT2.7/P4L3 White-Box Testing Subtitles/13 - Condition Coverage - lang_en_vs4.srt')
| -rw-r--r-- | usth/ICT2.7/P4L3 White-Box Testing Subtitles/13 - Condition Coverage - lang_en_vs4.srt | 191 |
1 files changed, 0 insertions, 191 deletions
diff --git a/usth/ICT2.7/P4L3 White-Box Testing Subtitles/13 - Condition Coverage - lang_en_vs4.srt b/usth/ICT2.7/P4L3 White-Box Testing Subtitles/13 - Condition Coverage - lang_en_vs4.srt deleted file mode 100644 index bba72fc..0000000 --- a/usth/ICT2.7/P4L3 White-Box Testing Subtitles/13 - Condition Coverage - lang_en_vs4.srt +++ /dev/null @@ -1,191 +0,0 @@ -1 -00:00:00,470 --> 00:00:03,046 -What I'm going to do next is to introduce a few additional - -2 -00:00:03,046 --> 00:00:06,350 -coverage criteria using a slightly more complex example, but still a - -3 -00:00:06,350 --> 00:00:09,370 -pretty simple one. What I'm showing here is a program that - -4 -00:00:09,370 --> 00:00:12,145 -reads two real numbers, x and y. And then, if x - -5 -00:00:12,145 --> 00:00:15,148 -is equal to 0 or y is greater than 0, it - -6 -00:00:15,148 --> 00:00:19,360 -computes y as y divided by x. Otherwise, it computes x - -7 -00:00:19,360 --> 00:00:22,110 -as y plus 2, then it writes the value of x, - -8 -00:00:22,110 --> 00:00:25,730 -the value of y, and it terminates. Let's also introduce a CFG - -9 -00:00:25,730 --> 00:00:29,160 -for the program. As you can see, the CFG represents the statements - -10 -00:00:29,160 --> 00:00:31,900 -in the code and their control flow. And in this case, I made - -11 -00:00:31,900 --> 00:00:35,800 -explicit over the branches what are the conditions under which those branches - -12 -00:00:35,800 --> 00:00:38,530 -are taken to make it simpler to look at the example. Let's assume - -13 -00:00:38,530 --> 00:00:41,280 -that we have two tests for this code that are shown here. - -14 -00:00:41,280 --> 00:00:44,286 -For the first one, the inputs are 5 and 5. For the second - -15 -00:00:44,286 --> 00:00:47,610 -one, 5 and minus 5. If we consider branch coverage for this code - -16 -00:00:47,610 --> 00:00:50,990 -and we consider the two test cases, for the first one this condition - -17 -00:00:50,990 --> 00:00:53,440 -is true. Because x is not equal to 0 but y - -18 -00:00:53,440 --> 00:00:56,660 -is greater than 0. And therefore, we will follow this tree branch. - -19 -00:00:56,660 --> 00:00:59,640 -For the second one, the condition is false. Because x is not - -20 -00:00:59,640 --> 00:01:03,200 -equal to 0 and y is not greater than 0. Therefore, the - -21 -00:01:03,200 --> 00:01:05,990 -negation of it is true and we will follow this branch. In - -22 -00:01:05,990 --> 00:01:09,530 -other words, these two test cases achieve 100% branch coverage on this - -23 -00:01:09,530 --> 00:01:12,120 -code. If we look at the code though, we can see that - -24 -00:01:12,120 --> 00:01:15,879 -there is the possibility of making this code fail. Consider this statement, - -25 -00:01:15,879 --> 00:01:18,147 -if x is equal to 0, we could have a division - -26 -00:01:18,147 --> 00:01:21,710 -by 0. However, these two test cases, despite the fact that - -27 -00:01:21,710 --> 00:01:25,008 -they achieved 100% branch coverage, will not rebuild this problem. So - -28 -00:01:25,008 --> 00:01:27,564 -how can we be more thorough? I'll let you think about it - -29 -00:01:27,564 --> 00:01:29,964 -for a second, so think about how can we test more - -30 -00:01:29,964 --> 00:01:33,260 -thoroughly, in a more complete way, this code. So, in a way - -31 -00:01:33,260 --> 00:01:37,220 -that goes beyond branch coverage. And the answer is that we - -32 -00:01:37,220 --> 00:01:41,250 -can make each condition true and false. Instead of just considering the - -33 -00:01:41,250 --> 00:01:44,570 -whole predicate here. And that's exactly what is required by - -34 -00:01:44,570 --> 00:01:47,480 -the next criteria that we're going to consider which is condition - -35 -00:01:47,480 --> 00:01:49,880 -coverage. We're going to define it as usual in terms of - -36 -00:01:49,880 --> 00:01:53,070 -test requirements and coverage measure. In this case, the test - -37 -00:01:53,070 --> 00:01:57,540 -requirements for condition coverage are the individual conditions in the - -38 -00:01:57,540 --> 00:02:00,510 -program. So we want each condition in the program to - -39 -00:02:00,510 --> 00:02:03,900 -be both true and false first time execution. So the - -40 -00:02:03,900 --> 00:02:06,420 -way in which we can measure that is by measuring the - -41 -00:02:06,420 --> 00:02:09,150 -number of conditions that were both true and false - -42 -00:02:09,150 --> 00:02:11,580 -when we executed our tests over the total number - -43 -00:02:11,580 --> 00:02:14,180 -of conditions. And that gives us the percentage of - -44 -00:02:14,180 --> 00:02:17,270 -coverage that we achieved for condition coverage. Again, if you - -45 -00:02:17,270 --> 00:02:18,638 -want to look at this criteria in the form - -46 -00:02:18,638 --> 00:02:21,245 -of a question. The question would be, has each boolean - -47 -00:02:21,245 --> 00:02:25,480 -sub-expression, which means every condition in every predicate, evaluated - -48 -00:02:25,480 --> 00:02:28,010 -both to true and false when we run our tests. |