What is code coverage and how do YOU measure it?
I was asked this question regarding our automating testing code coverage. It seems to be that, outside of automated tools, it is more art than science. Are there any real-world examples of how to use code coverage?
This question is related to
testing
computer-science
code-coverage
Code coverage has been explained well in the previous answers. So this is more of an answer to the second part of the question.
We've used three tools to determine code coverage.
We use these tools to
Just remember, having "100% code-coverage" doesn't mean everything is tested completely - while it means every line of code is tested, it doesn't mean they are tested under every (common) situation..
I would use code-coverage to highlight bits of code that I should probably write tests for. For example, if whatever code-coverage tool shows myImportantFunction() isn't executed while running my current unit-tests, they should probably be improved.
Basically, 100% code-coverage doesn't mean your code is perfect. Use it as a guide to write more comprehensive (unit-)tests.
Code coverage is simply a measure of the code that is tested. There are a variety of coverage criteria that can be measured, but typically it is the various paths, conditions, functions, and statements within a program that makeup the total coverage. The code coverage metric is the just a percentage of tests that execute each of these coverage criteria.
As far as how I go about tracking unit test coverage on my projects, I use static code analysis tools to keep track.
In the previous answers Code coverage has been explained well . I am just adding some knowledge related to tools if your are working on iOS
and OSX
platforms, Xcode provides the facility to test and monitor code coverage.
Reference Links:
https://medium.com/zendesk-engineering/code-coverage-and-xcode-6b2fb8756a51
Both are helpful links for learning and exploring code coverage with Xcode.
For Perl there's the excellent Devel::Cover module which I regularly use on my modules.
If the build and installation is managed by Module::Build you can simply run ./Build testcover
to get a nice HTML site that tells you the coverage per sub, line and condition, with nice colors making it easy to see which code path has not been covered.
Code coverage is simply a measure of the code that is tested. There are a variety of coverage criteria that can be measured, but typically it is the various paths, conditions, functions, and statements within a program that makeup the total coverage. The code coverage metric is the just a percentage of tests that execute each of these coverage criteria.
As far as how I go about tracking unit test coverage on my projects, I use static code analysis tools to keep track.
For Perl there's the excellent Devel::Cover module which I regularly use on my modules.
If the build and installation is managed by Module::Build you can simply run ./Build testcover
to get a nice HTML site that tells you the coverage per sub, line and condition, with nice colors making it easy to see which code path has not been covered.
Code coverage basically tells you how much of your code is covered under tests. For example, if you have 90% code coverage, it means 10% of the code is not covered under tests.
I know you might be thinking that if 90% of the code is covered, it's good enough, but you have to look from a different angle. What is stopping you from getting 100% code coverage?
A good example will be this:
if(customer.IsOldCustomer())
{
}
else
{
}
Now, in the code above, there are two paths/branches. If you are always hitting the "YES" branch, you are not covering the "else" part and it will be shown in the Code Coverage results. This is good because now you know that what is not covered and you can write a test to cover the "else" part. If there was no code coverage, you are just sitting on a time bomb, waiting to explode.
NCover is a good tool to measure code coverage.
Code coverage has been explained well in the previous answers. So this is more of an answer to the second part of the question.
We've used three tools to determine code coverage.
We use these tools to
Code coverage is simply a measure of the code that is tested. There are a variety of coverage criteria that can be measured, but typically it is the various paths, conditions, functions, and statements within a program that makeup the total coverage. The code coverage metric is the just a percentage of tests that execute each of these coverage criteria.
As far as how I go about tracking unit test coverage on my projects, I use static code analysis tools to keep track.
For Perl there's the excellent Devel::Cover module which I regularly use on my modules.
If the build and installation is managed by Module::Build you can simply run ./Build testcover
to get a nice HTML site that tells you the coverage per sub, line and condition, with nice colors making it easy to see which code path has not been covered.
For PHP you should take a look at the Github from Sebastian Bergmann
Provides collection, processing, and rendering functionality for PHP code coverage information.
Just remember, having "100% code-coverage" doesn't mean everything is tested completely - while it means every line of code is tested, it doesn't mean they are tested under every (common) situation..
I would use code-coverage to highlight bits of code that I should probably write tests for. For example, if whatever code-coverage tool shows myImportantFunction() isn't executed while running my current unit-tests, they should probably be improved.
Basically, 100% code-coverage doesn't mean your code is perfect. Use it as a guide to write more comprehensive (unit-)tests.
Complementing a few points to many of the previous answers:
Code coverage means, how well your test set is covering your source code. i.e. to what extent is the source code covered by the set of test cases.
As mentioned in above answers, there are various coverage criteria, like paths, conditions, functions, statements, etc. But additional criteria to be covered are
Note: Static code analysis will find if there are any unreachable code or hanging code, i.e. code not covered by any other function call. And also other static coverage. Even if static code analysis reports that 100% code is covered, it does not give reports about your testing set if all possible code coverage is tested.
In the previous answers Code coverage has been explained well . I am just adding some knowledge related to tools if your are working on iOS
and OSX
platforms, Xcode provides the facility to test and monitor code coverage.
Reference Links:
https://medium.com/zendesk-engineering/code-coverage-and-xcode-6b2fb8756a51
Both are helpful links for learning and exploring code coverage with Xcode.
Code coverage has been explained well in the previous answers. So this is more of an answer to the second part of the question.
We've used three tools to determine code coverage.
We use these tools to
Code coverage basically tells you how much of your code is covered under tests. For example, if you have 90% code coverage, it means 10% of the code is not covered under tests.
I know you might be thinking that if 90% of the code is covered, it's good enough, but you have to look from a different angle. What is stopping you from getting 100% code coverage?
A good example will be this:
if(customer.IsOldCustomer())
{
}
else
{
}
Now, in the code above, there are two paths/branches. If you are always hitting the "YES" branch, you are not covering the "else" part and it will be shown in the Code Coverage results. This is good because now you know that what is not covered and you can write a test to cover the "else" part. If there was no code coverage, you are just sitting on a time bomb, waiting to explode.
NCover is a good tool to measure code coverage.
For Perl there's the excellent Devel::Cover module which I regularly use on my modules.
If the build and installation is managed by Module::Build you can simply run ./Build testcover
to get a nice HTML site that tells you the coverage per sub, line and condition, with nice colors making it easy to see which code path has not been covered.
Complementing a few points to many of the previous answers:
Code coverage means, how well your test set is covering your source code. i.e. to what extent is the source code covered by the set of test cases.
As mentioned in above answers, there are various coverage criteria, like paths, conditions, functions, statements, etc. But additional criteria to be covered are
Note: Static code analysis will find if there are any unreachable code or hanging code, i.e. code not covered by any other function call. And also other static coverage. Even if static code analysis reports that 100% code is covered, it does not give reports about your testing set if all possible code coverage is tested.
Code coverage is simply a measure of the code that is tested. There are a variety of coverage criteria that can be measured, but typically it is the various paths, conditions, functions, and statements within a program that makeup the total coverage. The code coverage metric is the just a percentage of tests that execute each of these coverage criteria.
As far as how I go about tracking unit test coverage on my projects, I use static code analysis tools to keep track.
Just remember, having "100% code-coverage" doesn't mean everything is tested completely - while it means every line of code is tested, it doesn't mean they are tested under every (common) situation..
I would use code-coverage to highlight bits of code that I should probably write tests for. For example, if whatever code-coverage tool shows myImportantFunction() isn't executed while running my current unit-tests, they should probably be improved.
Basically, 100% code-coverage doesn't mean your code is perfect. Use it as a guide to write more comprehensive (unit-)tests.
Code coverage has been explained well in the previous answers. So this is more of an answer to the second part of the question.
We've used three tools to determine code coverage.
We use these tools to
Just remember, having "100% code-coverage" doesn't mean everything is tested completely - while it means every line of code is tested, it doesn't mean they are tested under every (common) situation..
I would use code-coverage to highlight bits of code that I should probably write tests for. For example, if whatever code-coverage tool shows myImportantFunction() isn't executed while running my current unit-tests, they should probably be improved.
Basically, 100% code-coverage doesn't mean your code is perfect. Use it as a guide to write more comprehensive (unit-)tests.
Code coverage basically tells you how much of your code is covered under tests. For example, if you have 90% code coverage, it means 10% of the code is not covered under tests.
I know you might be thinking that if 90% of the code is covered, it's good enough, but you have to look from a different angle. What is stopping you from getting 100% code coverage?
A good example will be this:
if(customer.IsOldCustomer())
{
}
else
{
}
Now, in the code above, there are two paths/branches. If you are always hitting the "YES" branch, you are not covering the "else" part and it will be shown in the Code Coverage results. This is good because now you know that what is not covered and you can write a test to cover the "else" part. If there was no code coverage, you are just sitting on a time bomb, waiting to explode.
NCover is a good tool to measure code coverage.
For PHP you should take a look at the Github from Sebastian Bergmann
Provides collection, processing, and rendering functionality for PHP code coverage information.
Code coverage basically tells you how much of your code is covered under tests. For example, if you have 90% code coverage, it means 10% of the code is not covered under tests.
I know you might be thinking that if 90% of the code is covered, it's good enough, but you have to look from a different angle. What is stopping you from getting 100% code coverage?
A good example will be this:
if(customer.IsOldCustomer())
{
}
else
{
}
Now, in the code above, there are two paths/branches. If you are always hitting the "YES" branch, you are not covering the "else" part and it will be shown in the Code Coverage results. This is good because now you know that what is not covered and you can write a test to cover the "else" part. If there was no code coverage, you are just sitting on a time bomb, waiting to explode.
NCover is a good tool to measure code coverage.
Source: Stackoverflow.com