MapWorkspace.tsx was 3.157 lines: a props interface, 1.200 lines of derived
state and handlers, and two complete render paths — the map-first explorer and
the advanced workbench behind it. It is now five modules, and the container is
nineteen lines that choose between the two.
The obstacle was the props signature. The explorer reads 97 derived values and
the workbench 40, so passing them individually would have produced a 97-field
interface — worse than the file it replaced. Extracting the derived state into
a hook that returns one object solves it: MapWorkspaceViewModel is
ReturnType<typeof useMapWorkspaceViewModel>, so the shape is derived from what
the hook actually produces and cannot drift from it. Each view then names two
typed objects, and the JSX moved unchanged.
The contract tests found the one place where widening a negative assertion is
wrong. "The map workspace performs no transport" was true of the old file and
false of the whole feature, because the hooks call the API by design. It is now
scoped to the presentational modules, which is what it always meant.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
MapWorkspace held five near-identical useMemo blocks deciding which raster
image the map draws under the active theme — terrain, flood depth, thematic
raster, WALOUS land cover and bathymetry. Each filtered partitions by source
name, read bbox_epsg4326 and assembled the same overlay shape, so the parts
that genuinely differ per theme were buried in the repetition.
One builder makes the rule testable and leaves only the source, the label and
the opacity varying. A raster whose bounds are unusable is now skipped rather
than drawn from a partial bbox: an overlay in the wrong place is worse than no
overlay.
The legend asked "are these thematic or WALOUS overlays" by inspecting two of
the five lists. That is a property of the source, so it says so directly.
Two contract tests needed fixing rather than repointing. One asserted
`"api" not in source.lower()`, which the new hook name useMapImageOverlays
matches inside "useM-api-mageOverlays" — as would rapid, capital or therapy.
The contract is that this component talks to no API client, so it now says
that.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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