Migrate GeoJSON blob viewer from Leaflet (raster) to MapLibre GL (vector)

Release notes

Replace the Leaflet raster tile library with MapLibre GL vector tiles for rendering GeoJSON files, removing a patched dependency and improving map rendering quality.

Problem to solve

The GeoJSON blob viewer depends on a patched version of Leaflet (patches/leaflet+1.9.4.patch). Maintaining a patched dependency is fragile and the raster tile approach produces blurry maps at high zoom levels with stepped/discrete zoom instead of continuous smooth zooming.

Proposal

Replace Leaflet with MapLibre GL JS using OpenFreeMap vector tiles:

  • Swap leaflet for maplibre-gl in package.json
  • Rewrite utils.js to use MapLibre's source/layer API with native geometry type styling (points, lines, polygons)
  • Add https://tiles.openfreemap.org to CSP connect_src
  • Delete patches/leaflet+1.9.4.patch
  • Update all related specs

Intended users

Feature Usage Metrics

No change — this replaces the rendering engine for an existing feature.

Does this feature require an audit event?

No.

Links / references

Edited by 🤖 GitLab Bot 🤖