How to test maplibre styles loading?

[guimochila]

Hi everyone,

We are implementing tests to our application, however when testing maplibre load/reload styles we are facing lots of instability in our tests, one of our engineers wrote:

the problem is that you apply a style change and need to verify that it was applied correctly on map, but you don’t know when exactly this style changes are done. Sometimes we wait for a specific number of features to be queried, other times we just set arbitrary timeout before we assert

How are can make sure that maplibre load and applied all changes to the map before we assert something?

Thanks in advance.

[IvanSanchez]

My guess would be to listen to data events (see https://maplibre.org/maplibre-gl-js-docs/api/map/#map.event:data and https://maplibre.org/maplibre-gl-js-docs/api/events/#mapdataevent), looking for a dataType property with a value of style.

[wipfli]

Or maybe this one? https://maplibre.org/maplibre-gl-js-docs/api/map/#map.event:render

[HarelM]

There's also the idle event.

[guimochila]

Thanks all, I will have a look at them, 'idle' seems to be an interesting approach.