[xwiki-devs] [VOTE] Add new check to measure quality of tests
Hi devs, As part of the STAMP research project, we’ve developed a new tool (Descartes, based on Pitest) to measure the quality of tests. It generates a mutation score for your tests, defining how good the tests are. Technical Descartes performs some extreme mutations on the code under test (e.g. remove content of void methods, return true for methods returning a boolean, etc - See https://github.com/STAMP-project/pitest-descartes). If the test continues to pass then it means it’s not killing the mutant and thus its mutation score decreases. So in short: * Jacoco/Clover: measure how much of the code is tested * Pitest/Descartes: measure how good the tests are Both provide a percentage value. I’m proposing to compute the current mutation scores for xwiki-commons and xwiki-rendering and fail the build when new code is added that reduce the mutation score threshold (exactly the same as our jacoco threshold and strategy). I consider this is an experiment to push the limit of software engineering a bit further. I don’t know how well it’ll work or not. I propose to do the work and test this for over 2-3 months and see how well it works or not. At that time we can then decide whether it works or not (i.e whether the gains it brings are more important than the problems it causes). Here’s my +1 to try this out. Some links: * pitest: http://pitest.org/ * descartes: https://github.com/STAMP-project/pitest-descartes * http://massol.myxwiki.org/xwiki/bin/view/Blog/ControllingTestQuality * http://massol.myxwiki.org/xwiki/bin/view/Blog/MutationTestingDescartes If you’re curious, you can see a screenshot of a mutation score report at http://massol.myxwiki.org/xwiki/bin/download/Blog/MutationTestingDescartes/r... Please cast your votes. Thanks -Vincent
+1 On Thu, Mar 15, 2018 at 9:30 AM, Vincent Massol <[email protected]> wrote:
Hi devs,
As part of the STAMP research project, we’ve developed a new tool (Descartes, based on Pitest) to measure the quality of tests. It generates a mutation score for your tests, defining how good the tests are. Technical Descartes performs some extreme mutations on the code under test (e.g. remove content of void methods, return true for methods returning a boolean, etc - See https://github.com/STAMP-project/pitest-descartes). If the test continues to pass then it means it’s not killing the mutant and thus its mutation score decreases.
So in short: * Jacoco/Clover: measure how much of the code is tested * Pitest/Descartes: measure how good the tests are
Both provide a percentage value.
I’m proposing to compute the current mutation scores for xwiki-commons and xwiki-rendering and fail the build when new code is added that reduce the mutation score threshold (exactly the same as our jacoco threshold and strategy).
I consider this is an experiment to push the limit of software engineering a bit further. I don’t know how well it’ll work or not. I propose to do the work and test this for over 2-3 months and see how well it works or not. At that time we can then decide whether it works or not (i.e whether the gains it brings are more important than the problems it causes).
Here’s my +1 to try this out.
Some links: * pitest: http://pitest.org/ * descartes: https://github.com/STAMP-project/pitest-descartes * http://massol.myxwiki.org/xwiki/bin/view/Blog/ControllingTestQuality * http://massol.myxwiki.org/xwiki/bin/view/Blog/MutationTestingDescartes
If you’re curious, you can see a screenshot of a mutation score report at http://massol.myxwiki.org/xwiki/bin/download/Blog/MutationTestingDescartes/r...
Please cast your votes.
Thanks -Vincent
-- Thomas Mortagne
+1 2018-03-15 11:26 GMT+01:00 Thomas Mortagne <[email protected]>:
+1
On Thu, Mar 15, 2018 at 9:30 AM, Vincent Massol <[email protected]> wrote:
Hi devs,
As part of the STAMP research project, we’ve developed a new tool (Descartes, based on Pitest) to measure the quality of tests. It generates a mutation score for your tests, defining how good the tests are. Technical Descartes performs some extreme mutations on the code under test (e.g. remove content of void methods, return true for methods returning a boolean, etc - See https://github.com/STAMP-project/pitest-descartes). If the test continues to pass then it means it’s not killing the mutant and thus its mutation score decreases.
So in short: * Jacoco/Clover: measure how much of the code is tested * Pitest/Descartes: measure how good the tests are
Both provide a percentage value.
I’m proposing to compute the current mutation scores for xwiki-commons and xwiki-rendering and fail the build when new code is added that reduce the mutation score threshold (exactly the same as our jacoco threshold and strategy).
I consider this is an experiment to push the limit of software engineering a bit further. I don’t know how well it’ll work or not. I propose to do the work and test this for over 2-3 months and see how well it works or not. At that time we can then decide whether it works or not (i.e whether the gains it brings are more important than the problems it causes).
Here’s my +1 to try this out.
Some links: * pitest: http://pitest.org/ * descartes: https://github.com/STAMP-project/pitest-descartes * http://massol.myxwiki.org/xwiki/bin/view/Blog/ControllingTestQuality * http://massol.myxwiki.org/xwiki/bin/view/Blog/MutationTestingDescartes
If you’re curious, you can see a screenshot of a mutation score report at http://massol.myxwiki.org/xwiki/bin/download/Blog/ MutationTestingDescartes/report.png
Please cast your votes.
Thanks -Vincent
-- Thomas Mortagne
-- Guillaume Delhumeau ([email protected]) Research & Development Engineer at XWiki SAS Committer on the XWiki.org project
Sounds interesting, +1. Thanks, Eduard On Thu, Mar 15, 2018 at 12:26 PM, Thomas Mortagne <[email protected]
wrote:
+1
On Thu, Mar 15, 2018 at 9:30 AM, Vincent Massol <[email protected]> wrote:
Hi devs,
As part of the STAMP research project, we’ve developed a new tool (Descartes, based on Pitest) to measure the quality of tests. It generates a mutation score for your tests, defining how good the tests are. Technical Descartes performs some extreme mutations on the code under test (e.g. remove content of void methods, return true for methods returning a boolean, etc - See https://github.com/STAMP-project/pitest-descartes). If the test continues to pass then it means it’s not killing the mutant and thus its mutation score decreases.
So in short: * Jacoco/Clover: measure how much of the code is tested * Pitest/Descartes: measure how good the tests are
Both provide a percentage value.
I’m proposing to compute the current mutation scores for xwiki-commons and xwiki-rendering and fail the build when new code is added that reduce the mutation score threshold (exactly the same as our jacoco threshold and strategy).
I consider this is an experiment to push the limit of software engineering a bit further. I don’t know how well it’ll work or not. I propose to do the work and test this for over 2-3 months and see how well it works or not. At that time we can then decide whether it works or not (i.e whether the gains it brings are more important than the problems it causes).
Here’s my +1 to try this out.
Some links: * pitest: http://pitest.org/ * descartes: https://github.com/STAMP-project/pitest-descartes * http://massol.myxwiki.org/xwiki/bin/view/Blog/ControllingTestQuality * http://massol.myxwiki.org/xwiki/bin/view/Blog/MutationTestingDescartes
If you’re curious, you can see a screenshot of a mutation score report at http://massol.myxwiki.org/xwiki/bin/download/Blog/ MutationTestingDescartes/report.png
Please cast your votes.
Thanks -Vincent
-- Thomas Mortagne
+1 Thanks, Caty On Thu, Mar 15, 2018 at 12:48 PM, Eduard Moraru <[email protected]> wrote:
Sounds interesting, +1.
Thanks, Eduard
On Thu, Mar 15, 2018 at 12:26 PM, Thomas Mortagne < [email protected]
wrote:
+1
On Thu, Mar 15, 2018 at 9:30 AM, Vincent Massol <[email protected]> wrote:
Hi devs,
As part of the STAMP research project, we’ve developed a new tool (Descartes, based on Pitest) to measure the quality of tests. It generates a mutation score for your tests, defining how good the tests are. Technical Descartes performs some extreme mutations on the code under test (e.g. remove content of void methods, return true for methods returning a boolean, etc - See https://github.com/STAMP-project/pitest-descartes). If the test continues to pass then it means it’s not killing the mutant and thus its mutation score decreases.
So in short: * Jacoco/Clover: measure how much of the code is tested * Pitest/Descartes: measure how good the tests are
Both provide a percentage value.
I’m proposing to compute the current mutation scores for xwiki-commons and xwiki-rendering and fail the build when new code is added that reduce the mutation score threshold (exactly the same as our jacoco threshold and strategy).
I consider this is an experiment to push the limit of software engineering a bit further. I don’t know how well it’ll work or not. I propose to do the work and test this for over 2-3 months and see how well it works or not. At that time we can then decide whether it works or not (i.e whether the gains it brings are more important than the problems it causes).
Here’s my +1 to try this out.
Some links: * pitest: http://pitest.org/ * descartes: https://github.com/STAMP-project/pitest-descartes * http://massol.myxwiki.org/xwiki/bin/view/Blog/ControllingTestQuality * http://massol.myxwiki.org/xwiki/bin/view/Blog/ MutationTestingDescartes
If you’re curious, you can see a screenshot of a mutation score report at http://massol.myxwiki.org/xwiki/bin/download/Blog/ MutationTestingDescartes/report.png
Please cast your votes.
Thanks -Vincent
-- Thomas Mortagne
+1 Thanks, Marius On Thu, Mar 15, 2018 at 12:49 PM, Ecaterina Moraru (Valica) < [email protected]> wrote:
+1
Thanks, Caty
On Thu, Mar 15, 2018 at 12:48 PM, Eduard Moraru <[email protected]> wrote:
Sounds interesting, +1.
Thanks, Eduard
On Thu, Mar 15, 2018 at 12:26 PM, Thomas Mortagne < [email protected]
wrote:
+1
On Thu, Mar 15, 2018 at 9:30 AM, Vincent Massol <[email protected]> wrote:
Hi devs,
As part of the STAMP research project, we’ve developed a new tool (Descartes, based on Pitest) to measure the quality of tests. It generates a mutation score for your tests, defining how good the tests are. Technical Descartes performs some extreme mutations on the code under test (e.g. remove content of void methods, return true for methods returning a boolean, etc - See https://github.com/STAMP-project/pitest-descartes). If the test continues to pass then it means it’s not killing the mutant and thus its mutation score decreases.
So in short: * Jacoco/Clover: measure how much of the code is tested * Pitest/Descartes: measure how good the tests are
Both provide a percentage value.
I’m proposing to compute the current mutation scores for xwiki-commons and xwiki-rendering and fail the build when new code is added that reduce the mutation score threshold (exactly the same as our jacoco threshold and strategy).
I consider this is an experiment to push the limit of software engineering a bit further. I don’t know how well it’ll work or not. I propose to do the work and test this for over 2-3 months and see how well it works or not. At that time we can then decide whether it works or not (i.e whether the gains it brings are more important than the problems it causes).
Here’s my +1 to try this out.
Some links: * pitest: http://pitest.org/ * descartes: https://github.com/STAMP-project/pitest-descartes * http://massol.myxwiki.org/xwiki/bin/view/Blog/ ControllingTestQuality * http://massol.myxwiki.org/xwiki/bin/view/Blog/ MutationTestingDescartes
If you’re curious, you can see a screenshot of a mutation score report at http://massol.myxwiki.org/xwiki/bin/download/Blog/ MutationTestingDescartes/report.png
Please cast your votes.
Thanks -Vincent
-- Thomas Mortagne
FYI I’ve implemented it locally for all modules of xwiki-commons and did some build time measurements: * With pitest/descartes: 37:16 minutes * Without pitest/descartes 5:10 minutes So that’s a pretty important hit…. So I think one strategy could be to not run pitest/descartes by default in the quality profile (i.e. have it off by default with <xwiki.pitest.skip>true</xwiki.pitest.skip>) and run it on the CI, from time to time, like once per day for example, or once per week. Small issue: I need to find/test a way to run a crontab type of job in a Jenkins pipeline script. I know how to do in theory but I need to test it and verify it works. I still have some doubts ATM... WDYT? Thanks -Vincent
On 15 Mar 2018, at 09:30, Vincent Massol <[email protected]> wrote:
Hi devs,
As part of the STAMP research project, we’ve developed a new tool (Descartes, based on Pitest) to measure the quality of tests. It generates a mutation score for your tests, defining how good the tests are. Technical Descartes performs some extreme mutations on the code under test (e.g. remove content of void methods, return true for methods returning a boolean, etc - See https://github.com/STAMP-project/pitest-descartes). If the test continues to pass then it means it’s not killing the mutant and thus its mutation score decreases.
So in short: * Jacoco/Clover: measure how much of the code is tested * Pitest/Descartes: measure how good the tests are
Both provide a percentage value.
I’m proposing to compute the current mutation scores for xwiki-commons and xwiki-rendering and fail the build when new code is added that reduce the mutation score threshold (exactly the same as our jacoco threshold and strategy).
I consider this is an experiment to push the limit of software engineering a bit further. I don’t know how well it’ll work or not. I propose to do the work and test this for over 2-3 months and see how well it works or not. At that time we can then decide whether it works or not (i.e whether the gains it brings are more important than the problems it causes).
Here’s my +1 to try this out.
Some links: * pitest: http://pitest.org/ * descartes: https://github.com/STAMP-project/pitest-descartes * http://massol.myxwiki.org/xwiki/bin/view/Blog/ControllingTestQuality * http://massol.myxwiki.org/xwiki/bin/view/Blog/MutationTestingDescartes
If you’re curious, you can see a screenshot of a mutation score report at http://massol.myxwiki.org/xwiki/bin/download/Blog/MutationTestingDescartes/r...
Please cast your votes.
Thanks -Vincent
On 27 Mar 2018, at 19:32, Vincent Massol <[email protected]> wrote:
FYI I’ve implemented it locally for all modules of xwiki-commons and did some build time measurements:
* With pitest/descartes: 37:16 minutes * Without pitest/descartes 5:10 minutes
Actually I was able to reduce the time to 15:12 minutes with configuring pitest with 4 threads. Thanks -Vincent
So that’s a pretty important hit….
So I think one strategy could be to not run pitest/descartes by default in the quality profile (i.e. have it off by default with <xwiki.pitest.skip>true</xwiki.pitest.skip>) and run it on the CI, from time to time, like once per day for example, or once per week.
Small issue: I need to find/test a way to run a crontab type of job in a Jenkins pipeline script. I know how to do in theory but I need to test it and verify it works. I still have some doubts ATM...
WDYT?
Thanks -Vincent
On 15 Mar 2018, at 09:30, Vincent Massol <[email protected]> wrote:
Hi devs,
As part of the STAMP research project, we’ve developed a new tool (Descartes, based on Pitest) to measure the quality of tests. It generates a mutation score for your tests, defining how good the tests are. Technical Descartes performs some extreme mutations on the code under test (e.g. remove content of void methods, return true for methods returning a boolean, etc - See https://github.com/STAMP-project/pitest-descartes). If the test continues to pass then it means it’s not killing the mutant and thus its mutation score decreases.
So in short: * Jacoco/Clover: measure how much of the code is tested * Pitest/Descartes: measure how good the tests are
Both provide a percentage value.
I’m proposing to compute the current mutation scores for xwiki-commons and xwiki-rendering and fail the build when new code is added that reduce the mutation score threshold (exactly the same as our jacoco threshold and strategy).
I consider this is an experiment to push the limit of software engineering a bit further. I don’t know how well it’ll work or not. I propose to do the work and test this for over 2-3 months and see how well it works or not. At that time we can then decide whether it works or not (i.e whether the gains it brings are more important than the problems it causes).
Here’s my +1 to try this out.
Some links: * pitest: http://pitest.org/ * descartes: https://github.com/STAMP-project/pitest-descartes * http://massol.myxwiki.org/xwiki/bin/view/Blog/ControllingTestQuality * http://massol.myxwiki.org/xwiki/bin/view/Blog/MutationTestingDescartes
If you’re curious, you can see a screenshot of a mutation score report at http://massol.myxwiki.org/xwiki/bin/download/Blog/MutationTestingDescartes/r...
Please cast your votes.
Thanks -Vincent
If you’re curious I’ve also added some more information at https://github.com/STAMP-project/pitest-descartes/issues/54 ATM, and even with a time of “only” 10mn to run pitest/descartes on xwiki-commons, it’s still too much IMO so I’ll work on turning it off by default but having a job to run it on the CI. Let me know if you have remarks. Thanks -Vincent
On 27 Mar 2018, at 20:09, Vincent Massol <[email protected]> wrote:
On 27 Mar 2018, at 19:32, Vincent Massol <[email protected]> wrote:
FYI I’ve implemented it locally for all modules of xwiki-commons and did some build time measurements:
* With pitest/descartes: 37:16 minutes * Without pitest/descartes 5:10 minutes
Actually I was able to reduce the time to 15:12 minutes with configuring pitest with 4 threads.
Thanks -Vincent
So that’s a pretty important hit….
So I think one strategy could be to not run pitest/descartes by default in the quality profile (i.e. have it off by default with <xwiki.pitest.skip>true</xwiki.pitest.skip>) and run it on the CI, from time to time, like once per day for example, or once per week.
Small issue: I need to find/test a way to run a crontab type of job in a Jenkins pipeline script. I know how to do in theory but I need to test it and verify it works. I still have some doubts ATM...
WDYT?
Thanks -Vincent
On 15 Mar 2018, at 09:30, Vincent Massol <[email protected]> wrote:
Hi devs,
As part of the STAMP research project, we’ve developed a new tool (Descartes, based on Pitest) to measure the quality of tests. It generates a mutation score for your tests, defining how good the tests are. Technical Descartes performs some extreme mutations on the code under test (e.g. remove content of void methods, return true for methods returning a boolean, etc - See https://github.com/STAMP-project/pitest-descartes). If the test continues to pass then it means it’s not killing the mutant and thus its mutation score decreases.
So in short: * Jacoco/Clover: measure how much of the code is tested * Pitest/Descartes: measure how good the tests are
Both provide a percentage value.
I’m proposing to compute the current mutation scores for xwiki-commons and xwiki-rendering and fail the build when new code is added that reduce the mutation score threshold (exactly the same as our jacoco threshold and strategy).
I consider this is an experiment to push the limit of software engineering a bit further. I don’t know how well it’ll work or not. I propose to do the work and test this for over 2-3 months and see how well it works or not. At that time we can then decide whether it works or not (i.e whether the gains it brings are more important than the problems it causes).
Here’s my +1 to try this out.
Some links: * pitest: http://pitest.org/ * descartes: https://github.com/STAMP-project/pitest-descartes * http://massol.myxwiki.org/xwiki/bin/view/Blog/ControllingTestQuality * http://massol.myxwiki.org/xwiki/bin/view/Blog/MutationTestingDescartes
If you’re curious, you can see a screenshot of a mutation score report at http://massol.myxwiki.org/xwiki/bin/download/Blog/MutationTestingDescartes/r...
Please cast your votes.
Thanks -Vincent
On Wed, Mar 28, 2018 at 1:25 PM, Vincent Massol <[email protected]> wrote:
If you’re curious I’ve also added some more information at https://github.com/STAMP-project/pitest-descartes/issues/54
ATM, and even with a time of “only” 10mn to run pitest/descartes on xwiki-commons, it’s still too much IMO so I’ll work on turning it off by default but having a job to run it on the CI.
Sounds good. I agree that we can't enable it all the time given the time lost.
Let me know if you have remarks.
Thanks -Vincent
On 27 Mar 2018, at 20:09, Vincent Massol <[email protected]> wrote:
On 27 Mar 2018, at 19:32, Vincent Massol <[email protected]> wrote:
FYI I’ve implemented it locally for all modules of xwiki-commons and did some build time measurements:
* With pitest/descartes: 37:16 minutes * Without pitest/descartes 5:10 minutes
Actually I was able to reduce the time to 15:12 minutes with configuring pitest with 4 threads.
Thanks -Vincent
So that’s a pretty important hit….
So I think one strategy could be to not run pitest/descartes by default in the quality profile (i.e. have it off by default with <xwiki.pitest.skip>true</xwiki.pitest.skip>) and run it on the CI, from time to time, like once per day for example, or once per week.
Small issue: I need to find/test a way to run a crontab type of job in a Jenkins pipeline script. I know how to do in theory but I need to test it and verify it works. I still have some doubts ATM...
WDYT?
Thanks -Vincent
On 15 Mar 2018, at 09:30, Vincent Massol <[email protected]> wrote:
Hi devs,
As part of the STAMP research project, we’ve developed a new tool (Descartes, based on Pitest) to measure the quality of tests. It generates a mutation score for your tests, defining how good the tests are. Technical Descartes performs some extreme mutations on the code under test (e.g. remove content of void methods, return true for methods returning a boolean, etc - See https://github.com/STAMP-project/pitest-descartes). If the test continues to pass then it means it’s not killing the mutant and thus its mutation score decreases.
So in short: * Jacoco/Clover: measure how much of the code is tested * Pitest/Descartes: measure how good the tests are
Both provide a percentage value.
I’m proposing to compute the current mutation scores for xwiki-commons and xwiki-rendering and fail the build when new code is added that reduce the mutation score threshold (exactly the same as our jacoco threshold and strategy).
I consider this is an experiment to push the limit of software engineering a bit further. I don’t know how well it’ll work or not. I propose to do the work and test this for over 2-3 months and see how well it works or not. At that time we can then decide whether it works or not (i.e whether the gains it brings are more important than the problems it causes).
Here’s my +1 to try this out.
Some links: * pitest: http://pitest.org/ * descartes: https://github.com/STAMP-project/pitest-descartes * http://massol.myxwiki.org/xwiki/bin/view/Blog/ControllingTestQuality * http://massol.myxwiki.org/xwiki/bin/view/Blog/MutationTestingDescartes
If you’re curious, you can see a screenshot of a mutation score report at http://massol.myxwiki.org/xwiki/bin/download/Blog/MutationTestingDescartes/r...
Please cast your votes.
Thanks -Vincent
-- Thomas Mortagne
FYI I’ve now committed this on issue https://jira.xwiki.org/browse/XCOMMONS-1385 for xwiki-commons. And I’ve created an adhoc job at http://ci.xwiki.org/job/xwiki-commons_pitest/ which executes PIT/Descartes (to be moved to our Jenkins pipeline later on). Let’s now make sure we fix the build when this job breaks and verify if the strategy works or not! Thanks -Vincent
On 15 Mar 2018, at 09:30, Vincent Massol <[email protected]> wrote:
Hi devs,
As part of the STAMP research project, we’ve developed a new tool (Descartes, based on Pitest) to measure the quality of tests. It generates a mutation score for your tests, defining how good the tests are. Technical Descartes performs some extreme mutations on the code under test (e.g. remove content of void methods, return true for methods returning a boolean, etc - See https://github.com/STAMP-project/pitest-descartes). If the test continues to pass then it means it’s not killing the mutant and thus its mutation score decreases.
So in short: * Jacoco/Clover: measure how much of the code is tested * Pitest/Descartes: measure how good the tests are
Both provide a percentage value.
I’m proposing to compute the current mutation scores for xwiki-commons and xwiki-rendering and fail the build when new code is added that reduce the mutation score threshold (exactly the same as our jacoco threshold and strategy).
I consider this is an experiment to push the limit of software engineering a bit further. I don’t know how well it’ll work or not. I propose to do the work and test this for over 2-3 months and see how well it works or not. At that time we can then decide whether it works or not (i.e whether the gains it brings are more important than the problems it causes).
Here’s my +1 to try this out.
Some links: * pitest: http://pitest.org/ * descartes: https://github.com/STAMP-project/pitest-descartes * http://massol.myxwiki.org/xwiki/bin/view/Blog/ControllingTestQuality * http://massol.myxwiki.org/xwiki/bin/view/Blog/MutationTestingDescartes
If you’re curious, you can see a screenshot of a mutation score report at http://massol.myxwiki.org/xwiki/bin/download/Blog/MutationTestingDescartes/r...
Please cast your votes.
Thanks -Vincent
Note: Now that this is done for xwiki-commons, I’d like to also do that for xwiki-rendering when I get the time. Thanks -Vincent
On 4 Apr 2018, at 16:14, Vincent Massol <[email protected]> wrote:
FYI I’ve now committed this on issue https://jira.xwiki.org/browse/XCOMMONS-1385 for xwiki-commons.
And I’ve created an adhoc job at http://ci.xwiki.org/job/xwiki-commons_pitest/ which executes PIT/Descartes (to be moved to our Jenkins pipeline later on).
Let’s now make sure we fix the build when this job breaks and verify if the strategy works or not!
Thanks -Vincent
On 15 Mar 2018, at 09:30, Vincent Massol <[email protected]> wrote:
Hi devs,
As part of the STAMP research project, we’ve developed a new tool (Descartes, based on Pitest) to measure the quality of tests. It generates a mutation score for your tests, defining how good the tests are. Technical Descartes performs some extreme mutations on the code under test (e.g. remove content of void methods, return true for methods returning a boolean, etc - See https://github.com/STAMP-project/pitest-descartes). If the test continues to pass then it means it’s not killing the mutant and thus its mutation score decreases.
So in short: * Jacoco/Clover: measure how much of the code is tested * Pitest/Descartes: measure how good the tests are
Both provide a percentage value.
I’m proposing to compute the current mutation scores for xwiki-commons and xwiki-rendering and fail the build when new code is added that reduce the mutation score threshold (exactly the same as our jacoco threshold and strategy).
I consider this is an experiment to push the limit of software engineering a bit further. I don’t know how well it’ll work or not. I propose to do the work and test this for over 2-3 months and see how well it works or not. At that time we can then decide whether it works or not (i.e whether the gains it brings are more important than the problems it causes).
Here’s my +1 to try this out.
Some links: * pitest: http://pitest.org/ * descartes: https://github.com/STAMP-project/pitest-descartes * http://massol.myxwiki.org/xwiki/bin/view/Blog/ControllingTestQuality * http://massol.myxwiki.org/xwiki/bin/view/Blog/MutationTestingDescartes
If you’re curious, you can see a screenshot of a mutation score report at http://massol.myxwiki.org/xwiki/bin/download/Blog/MutationTestingDescartes/r...
Please cast your votes.
Thanks -Vincent
On 22 May 2018, at 14:10, Vincent Massol <[email protected]> wrote:
Note: Now that this is done for xwiki-commons, I’d like to also do that for xwiki-rendering when I get the time.
It’s now done for xwiki-rendering too. Thanks -Vincent
Thanks -Vincent
On 4 Apr 2018, at 16:14, Vincent Massol <[email protected]> wrote:
FYI I’ve now committed this on issue https://jira.xwiki.org/browse/XCOMMONS-1385 for xwiki-commons.
And I’ve created an adhoc job at http://ci.xwiki.org/job/xwiki-commons_pitest/ which executes PIT/Descartes (to be moved to our Jenkins pipeline later on).
Let’s now make sure we fix the build when this job breaks and verify if the strategy works or not!
Thanks -Vincent
On 15 Mar 2018, at 09:30, Vincent Massol <[email protected]> wrote:
Hi devs,
As part of the STAMP research project, we’ve developed a new tool (Descartes, based on Pitest) to measure the quality of tests. It generates a mutation score for your tests, defining how good the tests are. Technical Descartes performs some extreme mutations on the code under test (e.g. remove content of void methods, return true for methods returning a boolean, etc - See https://github.com/STAMP-project/pitest-descartes). If the test continues to pass then it means it’s not killing the mutant and thus its mutation score decreases.
So in short: * Jacoco/Clover: measure how much of the code is tested * Pitest/Descartes: measure how good the tests are
Both provide a percentage value.
I’m proposing to compute the current mutation scores for xwiki-commons and xwiki-rendering and fail the build when new code is added that reduce the mutation score threshold (exactly the same as our jacoco threshold and strategy).
I consider this is an experiment to push the limit of software engineering a bit further. I don’t know how well it’ll work or not. I propose to do the work and test this for over 2-3 months and see how well it works or not. At that time we can then decide whether it works or not (i.e whether the gains it brings are more important than the problems it causes).
Here’s my +1 to try this out.
Some links: * pitest: http://pitest.org/ * descartes: https://github.com/STAMP-project/pitest-descartes * http://massol.myxwiki.org/xwiki/bin/view/Blog/ControllingTestQuality * http://massol.myxwiki.org/xwiki/bin/view/Blog/MutationTestingDescartes
If you’re curious, you can see a screenshot of a mutation score report at http://massol.myxwiki.org/xwiki/bin/download/Blog/MutationTestingDescartes/r...
Please cast your votes.
Thanks -Vincent
participants (6)
-
Ecaterina Moraru (Valica) -
Eduard Moraru -
Guillaume Delhumeau -
Marius Dumitru Florea -
Thomas Mortagne -
Vincent Massol