Many C API functions lack tests

[dbaston]

Functions and code paths not tested can be seen in this codecov report: https://codecov.io/gh/libgeos/geos/src/master/capi/geos_ts_c.cpp. You should be able to view it without an account at least once, but it seems to require login after a few page views.

This would be a great task for anyone who wants to begin contributing to GEOS.

The behavior of the underlying operations is generally tested elsewhere, but C API tests should at least verify that

• the function correctly operates with trivial inputs
• it preserves SRID, if applicable
• it returns the documented error code on error (if you can think of a way to trigger an error)

[jericks]

I would like to help out with this. Would you prefer one big pull request or several smaller pull requests (one for function)?

[dbaston]

However you prefer to do it is good by me. Thanks!

[jericks]

I started by writing tests for GEOSDisjoint and GEOSTouches:

master...jericks:codecov

[dbaston]

Thanks! Here are my suggestions:

• instead of creating local variables for the test geometries, use the built-in member variables geom1_, geom2_, etc. These will be automatically cleaned up, so you don't need to call GEOSGeom_destroy. You can peek at the capitest::utility class to see a full list.
• if you can test the necessary code paths with two geometries instead of three, that's better
• if you can test the necessary code paths with easily-readable geometries like POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0)), that's better

[jericks]

To test all the *_r functions should add a struct utility_r to the capi_test_utils?

[dbaston]

I see the appeal but am not sure it's worth it, since the non-_r functions are just trivial wrappers around the _r versions.

[dbaston]

@jericks , any objection to me merging in the commits from your codecov branch?

[jericks]

No objections here.

…

On Wed, Oct 20, 2021, 4:19 PM Dan Baston ***@***.***> wrote: @jericks <https://github.com/jericks> , any objection to me merging in the commits from your codecov branch? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#396 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AABUKTYA3OGLKJJUCCWO4V3UH5FBHANCNFSM4W5CK7QQ> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>.

[dbaston]

Still seems a worthy goal, IMO.

[dbaston]

This is in pretty good shape now.