Thanks for the proposal @mfarmer-ara!

It looks like there is no defined behavior for this detailed in the GeoJSON spec. So we should be free to add additional behavior as needed, as long as it is documented.

Can you explain more what you mean by the "next" key? In JavaScript, object properties do not have a guaranteed order.

4.3.3 Object
An object is a member of the type Object. It is an unordered collection of properties each of which contains a primitive value, object, or function. A function stored in a property of an object is called a method.

Can you explain more what you mean by the "next" key? In JavaScript, object properties do not have a guaranteed order.

It seems like the order Cesium will loop through the keys in that linked function is dependent on the original order it is in the file (observation not guaranteed).

So, while it doesn't really matter what order the keys are in usually, since it appears their order is kept based on the original file, that function will return what it thinks is the best name based on the order they're lopped through.

Though now I'm confusing myself with the precedence that's in that function.

I may play around with this today/tomorrow to see if I can pin things down.

@ggetz I'm still poking at this, but it looks like my example files might have been too simple. I am not able to make it happen with my simpler files but a geojson file with a polygon with 212 points (x,y,z) is consistently saying name (properties.title) is defined and skipping the extra property check. Since I am not sure I can share that one, I made a crazy shape with geojson.io with a similar number of points.

My tests were bad but in the sort of I was tricking myself way. I've figured out a way around this and will put a PR up that will hopefully work for eveyr

Keeping below, but I had an error in my testing files where title was set to be title: and not title for the simple files. So this is only relevant for the randomShape file, whose behavior is what I'm seeing.

Dragging and dropping this with the viewerDragDropMixin then clicking the shape shows the issue. It may be a race condition somewhere and not what I originally thought it might be. A smaller file (those shared earlier) the name is undefined but this file the name is defined as empty.

-- putting console.log({ name, defined: defined(name), properties }); in GeoJsonDataSource.js ~ line 136.

randomShape.json

{ "name": "", "defined": true, "properties": { "title": "", "description": "", "country-name": "North Carolina", "two-letter-code": "NC", "fill": "#f0a3FF", "fill-opacity": "0.5" } }

Files shared earlier (simple shape)
{ "defined": false, "properties": { "title:": "", "description": "", "country-name": "North Carolina", "two-letter-code": "NC", "fill": "#f0a3FF", "fill-opacity": "0.5" } }

Sorry for the extra comments while I explored this issue. The fix I've looked is to simply check if title is empty next to the defined() check for GeoJSON data sources.

With only title (no name or includes name/title keys) present and title equal to empty string, the below behavior happens. Is that fine? It behaves just as if title didn't exist at all.

With only title (no name or includes name/title keys) present and title equal to empty string, the below behavior happens. Is that fine? It behaves just as if title didn't exist at all.

This seems in line with expect behavior, yes.