From 8a7dfa0972c83fd811a4296e7373574bea4a28d0 Mon Sep 17 00:00:00 2001 From: Nguyễn Gia Phong Date: Sun, 19 Jul 2020 20:34:40 +0700 Subject: [usth/ICT2.7] Remove Udacity transcribes --- ...ify Constraints Among Choices - lang_en_vs4.srt | 239 --------------------- 1 file changed, 239 deletions(-) delete mode 100644 usth/ICT2.7/P4L2 Black-Box Testing Subtitles/20 - Identify Constraints Among Choices - lang_en_vs4.srt (limited to 'usth/ICT2.7/P4L2 Black-Box Testing Subtitles/20 - Identify Constraints Among Choices - lang_en_vs4.srt') diff --git a/usth/ICT2.7/P4L2 Black-Box Testing Subtitles/20 - Identify Constraints Among Choices - lang_en_vs4.srt b/usth/ICT2.7/P4L2 Black-Box Testing Subtitles/20 - Identify Constraints Among Choices - lang_en_vs4.srt deleted file mode 100644 index 0278cc8..0000000 --- a/usth/ICT2.7/P4L2 Black-Box Testing Subtitles/20 - Identify Constraints Among Choices - lang_en_vs4.srt +++ /dev/null @@ -1,239 +0,0 @@ -1 -00:00:00,160 --> 00:00:02,080 -Something that we saw when we were looking at the split - -2 -00:00:02,080 --> 00:00:05,760 -program before is that if we just combine the interesting values that - -3 -00:00:05,760 --> 00:00:08,490 -we identify, we might end up with a lot of cases. - -4 -00:00:08,490 --> 00:00:11,030 -And I mentioned that we, we're going to look at some way of - -5 -00:00:11,030 --> 00:00:13,720 -addressing that problem. And this is exactly what happens in the - -6 -00:00:13,720 --> 00:00:17,420 -next step of the category partition method, in which we identify constraints - -7 -00:00:17,420 --> 00:00:20,510 -among choices. And why do we identify these constraints? We do - -8 -00:00:20,510 --> 00:00:23,440 -that to eliminate meaningless combinations of - -9 -00:00:23,440 --> 00:00:25,460 -inputs. If you remember, for example, - -10 -00:00:25,460 --> 00:00:27,260 -we had the case in which we were trying to - -11 -00:00:27,260 --> 00:00:30,110 -create a string with a size less than 0, which - -12 -00:00:30,110 --> 00:00:32,930 -doesn't make any sense. And very importantly, we also do - -13 -00:00:32,930 --> 00:00:37,070 -that to reduce the number of test cases. Because every time - -14 -00:00:37,070 --> 00:00:40,930 -we constrain one of the possible choices, we eliminate possible - -15 -00:00:40,930 --> 00:00:43,250 -test cases, so we can use it to keep under - -16 -00:00:43,250 --> 00:00:45,960 -control the number of tests that we generate. There are - -17 -00:00:45,960 --> 00:00:47,571 -three types of properties. The - -18 -00:00:47,571 --> 00:00:50,610 -pair property...if, error properties, and properties - -19 -00:00:50,610 --> 00:00:52,610 -of type single. So we're going to look at what these - -20 -00:00:52,610 --> 00:00:56,230 -properties mean, using, once more, our example of the split program. - -21 -00:00:56,230 --> 00:00:58,750 -In particular, we're going to use some of the choices that we - -22 -00:00:58,750 --> 00:01:02,080 -identified earlier. So let's look, for example, at choice 0, for - -23 -00:01:02,080 --> 00:01:04,599 -category length of the string. All we can say is that, - -24 -00:01:04,599 --> 00:01:07,860 -if the length is 0, this define a special property of - -25 -00:01:07,860 --> 00:01:11,160 -the string. And that was specified in this way by saying - -26 -00:01:11,160 --> 00:01:15,610 -that this identifies property zerovalue. So every time that we use - -27 -00:01:15,610 --> 00:01:19,080 -this choice, zerovalue is defined. At this point, we can use - -28 -00:01:19,080 --> 00:01:20,550 -this to exclude some meaningless - -29 -00:01:20,550 --> 00:01:23,170 -combinations. For instance, consider special characters. - -30 -00:01:23,170 --> 00:01:25,130 -If we have a string of length 0, which means a - -31 -00:01:25,130 --> 00:01:26,850 -string with no characters. Obviously, there - -32 -00:01:26,850 --> 00:01:28,760 -cannot be special characters. So, considering - -33 -00:01:28,760 --> 00:01:31,020 -this combination will just be a waste of time. So what - -34 -00:01:31,020 --> 00:01:33,770 -we do is that we specify next to this choice, that we - -35 -00:01:33,770 --> 00:01:36,360 -will only consider this if length is not 0. And we - -36 -00:01:36,360 --> 00:01:41,110 -do this by saying that we consider this only if not zerovalue. - -37 -00:01:41,110 --> 00:01:43,970 -So, if zerovalue is not defined. So this pair is an - -38 -00:01:43,970 --> 00:01:47,640 -example of a property...if case. Define a property and use that - -39 -00:01:47,640 --> 00:01:49,770 -property. Now let's look at a case in which we might - -40 -00:01:49,770 --> 00:01:52,580 -want to use an error property. For instance, when we look at - -41 -00:01:52,580 --> 00:01:56,480 -the category value for the input size, the choice value less - -42 -00:01:56,480 --> 00:01:59,510 -than 0 is an erroneous choice. So it's a choice that - -43 -00:01:59,510 --> 00:02:02,630 -we selected to test a possibly erroneous situation, so we can - -44 -00:02:02,630 --> 00:02:06,160 -mark this as an error property. And what that means is that - -45 -00:02:06,160 --> 00:02:09,949 -when generating a combination of choices, we will consider this only - -46 -00:02:09,949 --> 00:02:12,990 -once because we assume that we just want to test this error condition - -47 -00:02:12,990 --> 00:02:16,260 -once. Finally, the single property is a property that we use - -48 -00:02:16,260 --> 00:02:19,050 -when we want to limit the number of test cases. And it's - -49 -00:02:19,050 --> 00:02:21,900 -similar as an effect to error. It just has a different - -50 -00:02:21,900 --> 00:02:24,410 -meaning. So what we do when we use the single property is - -51 -00:02:24,410 --> 00:02:27,420 -that we're saying that this choice, we want to use in only - -52 -00:02:27,420 --> 00:02:31,120 -one combination. So don't combine it multiple times. And that, of course, - -53 -00:02:31,120 --> 00:02:34,260 -given the combinatorial nature of the problem, cuts down dramatically - -54 -00:02:34,260 --> 00:02:36,370 -the number of test cases. And we might use, for - -55 -00:02:36,370 --> 00:02:39,500 -instance, the single property for maxint, which means that we - -56 -00:02:39,500 --> 00:02:41,890 -will only have one test case in which the size is - -57 -00:02:41,890 --> 00:02:44,300 -equal to maxint. We're actually going to see a demo - -58 -00:02:44,300 --> 00:02:46,880 -on this topic so we'll have more chances of seeing how - -59 -00:02:46,880 --> 00:02:49,370 -properties work in practice and how good they are at - -60 -00:02:49,370 --> 00:02:53,022 -eliminating meaningless combinations and at reducing the number of test cases. -- cgit 1.4.1