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And the answer in this case is no. And
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the reason for this is because this code is
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unreachable. This is dead code because no matter the
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value of j, this condition will always be false because
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i will always be 0. And notice that this
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is a small example, but another important truth is
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that any non-trivial program contains dead or unreachable code,
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code that no matter how well we test our system,
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we will never be able to exercise. Why is that? Various
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reasons. For example, defensive programming or,
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for example, developing for future releases.
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So there might be pieces of code that are added, but they're
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still not activated. They're still not invoked by any other part of
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the code because of modifications to the code. There are some
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parts that were executed before and in the new version of the
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program, they are no longer exercised. They are no longer executable. But
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they still remain in the code base. And this is a very,
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very normal situation for this reason and many more. And this is
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an important concept because this affects
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the very meaning of coverage measures. If
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there is some unreachable code, we will never be able to reach
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100% code coverage. And in fact, if you remember, at the beginning of
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the lesson, we discussed this concept and asked you why you think
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that, in the industry, the target for coverage is not 100% but less
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that that. And that's the answer, to account for the fact that there
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are infeasibility problems that I have to take into account when I test
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the code, infeasible paths, unexecutable statements, conditions that can never
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be true, and so on. So most criteria, if not
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all, are affected, and we need to take that into
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account when we try to achieve a given coverage target.
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