Make CleanInt CleanNumeric parallel safe

[jsanz]

I realized that I skipped CleanInt and CleanNumeric on my last PR 😞. These two functions implemented the same approach as the as_numeric on OpenMapTiles repo, with the only difference being that these return NULL instead of -1. The approach of using an exception avoids running them in parallel.

Hence, I decided to bring the regular expression approach to these functions I proposed on openmaptiles/openmaptiles#728. Here there is already a testing mechanism, so I added more checks to ensure more cases are covered. I also improved a bit the tests to allow compare rounded results against a given number of decimals, instead of using floor.

Finally, I updated the Travis configuration, since the current one was not working properly. This took more than expected (in fact ended up almost using the same configuration used at CartoDB/cartodb-postgresql, but the outcome is good in my opinion, since we now can test all the functions in PostGIS 2.5 on Postgres 9.6, 10, 11, and 12 and PostGIS 3 on 12. You can see the build execution in my Travis account.

I also found another issue, the function OrientedEnvelope, equivalent to PostGIS 3 ST_OrientedEnvelope but implemented in SQL, yields different results in PostGIS 2.5 and 3. I haven't put time debugging the algorithm, we may want to open a new issue for this, but not sure about how much is worth, being PostGIS 3 the current stable release.

If this PR is merged, we can then make OpenMapTiles as_numeric to be just a wrapper to return a -1, or if it makes more sense, just replace the function to use CleanNumeric I actually prefer a function like this to return a null value instead of a value that is a valid input.

cc. @nyurik

[nyurik]

looks good, thanks! two minor cleanups, and this is good to go.

[nyurik]

@klokan could you enable https://travis-ci.org/openmaptiles/postgis-vt-util to run this? Thanks!

[jsanz]

@nyurik thanks for your feedback 🤗

@eva-j @MartinMikita let me know if there's anything else I can do to improve this PR. After this, we can update the function in the OpenMapTiles repo as a simple case statement wrapping this function.

[nyurik]

thanks, awesome work!

[sfkeller]

Out of curiosity: Which query / function uses CleanInt(text)?
/cc @jsanz

[jsanz]

@sfkeller this is a generic library of SQL functions.

In the context of OpenMapTiles CleanInt is not used (AFAIK) and CleanNumeric will eventually be used to replace as_numeric, but there's no PR for that yet, only a preliminary work here to have a function with the same parameter and expected output.