Sounds like we might want to fix whatever parsing is happening inside the code running on maps.wikimedia.org -- it should probably treat an empty properties object the same as an entirely absent one.

Failing that, the extension generating the mapframe tag could be updated to not output this.

There are an awful lot of "Failed to parse color" errors, roughly 40,000 per day. As part of investigating this task, we should make sure that the error is handled gracefully, e.g. a default color is used.

I tried to dig a bit into the code:

• The error message seems to come from a library deep, deep in the nodes_module tree: https://github.com/search?l=JavaScript&q=%22Failed+to+parse+color%22&type=Code
• I found the line of code that adds the empty "properties": {} in the first place. Unfortunately it's in a library we are not supposed to touch. https://phabricator.wikimedia.org/diffusion/EKAR/browse/master/lib/external/mapbox/mapbox-lib.js$11418
• It might still be possible to strip it before it shows up in the VisualEditor dialog.
• However, I don't think we should do this. It's actually useful to have this as boilerplate. This makes it much easier to manually add properties like a "marker-color".
• I tried to find a place where a function is assigned to something related to fill. My best guess is this: https://phabricator.wikimedia.org/diffusion/EKAR/browse/master/lib/external/mapbox/mapbox-lib.js$15116

My current guess is that we updated something to a more recent version, but forgot to update a dependency. It appears like some code intentionally feeds functions to a library for some kind of indirection. The library is supposed to resolve the function by calling it, but instead fails with the error message we see.

I imagine that VE controls the wiring between its input field and the lower-level libraries, so perhaps we just strip the empty properties out at the step of sending this text to the library?

In T308560#7974505, @thiemowmde wrote:

• The error message seems to come from a library deep, deep in the nodes_module tree: https://github.com/search?l=JavaScript&q=%22Failed+to+parse+color%22&type=Code

That one is a test file so not relevant.

I'm afraid this might be coming from the native dependency. I can't find the string anywhere else in kartotherian or its node_modules.

root@99ff4d40246e:/usr/lib# strings libmapnik.so.3.0.22  | grep 'Failed to parse color'
Failed to parse color: "

We discovered that the error starts with bad output from the mapdata API. An empty properties object "properties": {} in GeoJSON gets reserialized by Kartographer as an array, and is sent back to geoshapes as an array, properties: []. We need to fix the output from the mapdata API.

Change 802785 had a related patch set uploaded (by Awight; author: Awight):

[mediawiki/extensions/Kartographer@master] Set empty properties to null

https://gerrit.wikimedia.org/r/802785

Change 802891 had a related patch set uploaded (by Thiemo Kreuz (WMDE); author: Thiemo Kreuz (WMDE)):

[mediawiki/extensions/Kartographer@master] Force empty properties to be JSON serialized as an object

https://gerrit.wikimedia.org/r/802891

An empty properties object […] gets reserialized by Kartographer as an array

Uh, nice find! The JSON serializer responsible for this is FormatJson from core. There is even a comment that explains "Empty arrays are encoded as numeric arrays, not as objects, so cast any associative array that might be empty to an object before encoding it." I gave it a try: https://gerrit.wikimedia.org/r/802891

Change 802785 abandoned by Awight:

[mediawiki/extensions/Kartographer@master] Set empty properties to null

Reason:

https://gerrit.wikimedia.org/r/802785

Change 802891 merged by jenkins-bot:

[mediawiki/extensions/Kartographer@master] Force empty properties to be JSON serialized as an object

https://gerrit.wikimedia.org/r/802891

I found this morning in logstash an undefined offset in Kartographer which I have filed as T311037 , it might be related to a recent fix made for this task?