Re: Email to hackers for test coverage

On Thu, Aug 22, 2019 at 2:46 PM movead(dot)li(at)highgo(dot)ca <movead(dot)li(at)highgo(dot)ca>
wrote:

> Hello hackers,
>
> One of the area that didn't get much attention in the community
> recently is analysing and increasing the code coverage of
> PostgreSQL regession test suite. I have started working on the
> code coverage by running the GCOV code coverage analysis tool in
> order to analyse the current code coverage and come up with test
> cases to increase the code coverage. This is going to be a long
> exercise so my plan is do it incrementaly. I will be analysing
> some area of untested code and then coming up with test cases to
> test those lines of code in regression and then moving on next
> area of untested code and so on.
>
> So far I have come up with 3 test cases to increase the code
> coverage of PostgreSQL regression test suite.
>
> I have performed the regression run for this exercise on this commit:
> (Commit version 75c1921cd6c868c5995b88113b4463a4830b9a27):
>
> The regression is executed with make check-world command and the
> results are gathered using 'make coverage-html' command.
>
> Below are the lines of untested code that i have analysed and the
> test cases added to regression to test these as part of regression.
>
> *1. src/include/utils/float.h:140*
>
> Analyze:
> This is an error report line when converting a big float8 value
> which a float4 can not storage to float4.
>
> Test case:
> Add a test case as below in file float4.sql:
> select float4(1234567890123456789012345678901234567890::float8);
>
> *2. src/include/utils/float.h:145*
>
> Analyze:
> This is an error report line when converting a small float8 value
> which a float4 can not storage to float4.
>
> Test case:
> Add a test case as below in file float4.sql:
> select float4(0.0000000000000000000000000000000000000000000001::float8);
>
> *3.src/include/utils/sortsupport.h:264*
>
> Analyze:
> It is reverse sorting for the data type that has abbreviated for
> sort, for example macaddr, uuid, numeric, network and I choose
> numeric to do it.
>
> Test cast:
> Add a test case as below in file numeric.sql:
> INSERT INTO num_input_test(n1) values('99999999999999999999999999.998');
> INSERT INTO num_input_test(n1) values('99999999999999999999999999.997');
> SELECT * FROM num_input_test ORDER BY n1 DESC;
>
> Result and patch
>
> By adding the test cases, the test coverage of float.h increased from
> 97.7% to 100% and sortsupport.h increased from 76.7% to 80.0%.
>
> The increase in code coverage can be seen in the before and after
> pictures of GCOV test coverage analysis summary.
>
> The attached patch contain the test cases added in regression for
> increasing the coverage.
>
>
> --
> Movead Li
>

Hi Movead,
Please add that to commitfest.

--
Ibrar Ahmed