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Diffstat (limited to 'usth/ICT2.7/P4L3 White-Box Testing Subtitles/29 - Review Quiz Solution - lang_en_vs4.srt')
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diff --git a/usth/ICT2.7/P4L3 White-Box Testing Subtitles/29 - Review Quiz Solution - lang_en_vs4.srt b/usth/ICT2.7/P4L3 White-Box Testing Subtitles/29 - Review Quiz Solution - lang_en_vs4.srt deleted file mode 100644 index 1e3228c..0000000 --- a/usth/ICT2.7/P4L3 White-Box Testing Subtitles/29 - Review Quiz Solution - lang_en_vs4.srt +++ /dev/null @@ -1,119 +0,0 @@ -1 -00:00:00,230 --> 00:00:02,520 -And the answer in this case is no. And - -2 -00:00:02,520 --> 00:00:05,480 -the reason for this is because this code is - -3 -00:00:05,480 --> 00:00:08,950 -unreachable. This is dead code because no matter the - -4 -00:00:08,950 --> 00:00:12,560 -value of j, this condition will always be false because - -5 -00:00:12,560 --> 00:00:14,770 -i will always be 0. And notice that this - -6 -00:00:14,770 --> 00:00:17,670 -is a small example, but another important truth is - -7 -00:00:17,670 --> 00:00:22,520 -that any non-trivial program contains dead or unreachable code, - -8 -00:00:22,520 --> 00:00:25,610 -code that no matter how well we test our system, - -9 -00:00:25,610 --> 00:00:28,450 -we will never be able to exercise. Why is that? Various - -10 -00:00:28,450 --> 00:00:31,030 -reasons. For example, defensive programming or, - -11 -00:00:31,030 --> 00:00:33,600 -for example, developing for future releases. - -12 -00:00:33,600 --> 00:00:36,320 -So there might be pieces of code that are added, but they're - -13 -00:00:36,320 --> 00:00:39,380 -still not activated. They're still not invoked by any other part of - -14 -00:00:39,380 --> 00:00:41,970 -the code because of modifications to the code. There are some - -15 -00:00:41,970 --> 00:00:44,480 -parts that were executed before and in the new version of the - -16 -00:00:44,480 --> 00:00:47,915 -program, they are no longer exercised. They are no longer executable. But - -17 -00:00:47,915 --> 00:00:50,760 -they still remain in the code base. And this is a very, - -18 -00:00:50,760 --> 00:00:54,560 -very normal situation for this reason and many more. And this is - -19 -00:00:54,560 --> 00:00:56,790 -an important concept because this affects - -20 -00:00:56,790 --> 00:00:58,760 -the very meaning of coverage measures. If - -21 -00:00:58,760 --> 00:01:01,225 -there is some unreachable code, we will never be able to reach - -22 -00:01:01,225 --> 00:01:04,709 -100% code coverage. And in fact, if you remember, at the beginning of - -23 -00:01:04,709 --> 00:01:07,380 -the lesson, we discussed this concept and asked you why you think - -24 -00:01:07,380 --> 00:01:10,470 -that, in the industry, the target for coverage is not 100% but less - -25 -00:01:10,470 --> 00:01:12,850 -that that. And that's the answer, to account for the fact that there - -26 -00:01:12,850 --> 00:01:15,890 -are infeasibility problems that I have to take into account when I test - -27 -00:01:15,890 --> 00:01:19,920 -the code, infeasible paths, unexecutable statements, conditions that can never - -28 -00:01:19,920 --> 00:01:22,780 -be true, and so on. So most criteria, if not - -29 -00:01:22,780 --> 00:01:24,620 -all, are affected, and we need to take that into - -30 -00:01:24,620 --> 00:01:27,270 -account when we try to achieve a given coverage target. |