fix: invalid configurator state breaks "copy and edit this visualization" button

[mburri]

For this visualization: https://int.visualize.admin.ch/en/v/xyBVyFkko--k?dataSource=Int

If the user clicks "copy and edit this visualization", the editor quickly loads, but the user then gets redirected to the app index page.

The console shows an error: Error while decoding configurator state

The problem was, that the property measureId for MapSymbolLayers was declared as measureId: t.string in the type, but then the property gets unset in the reduces when the user selects "None" as measurement:

In this case, the property was completely removed from the symbol layer - which then broke decoding. Decoding only happens when a config is reopened for editing, but not when the visualization is shown.

Making the measureId property optional fixed the issue.

I transferred the exact same view config to the preview deployment: https://visualization-tool-git-fix-invalid-co-9d0f93-visualize-admin-ch.vercel.app/en/v/xyBVyFkko--k?dataSource=Int

The copy and edit button now works with existing visualizations, no config migration is needed.

• I added a CHANGELOG entry
• I made a self-review of my own code
• I wrote tests for the changes (if applicable)
  - [ ] I wrote configurator and chart config migrations (if applicable)

[vercel]

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Project	Deployment	Actions	Updated (UTC)
visualization-tool	Ready	Preview, Comment	Jul 9, 2026 11:38am