Introduces the RadarSource seam and the manifest it speaks, plus the demo
frames that make the app runnable with no network and no credentials.
MockRadarSource is a real adapter rather than test scaffolding, and that is
what makes the rest of milestone 3 testable: the timeline, prefetching, cache
eviction and every degraded path can be exercised offline because the demo
frames parse the same manifest document the Python worker will publish. Its
assets come from tool/generate_mock_frames.py — committed so the app runs from
a clone, generated by a script so they can be regenerated instead of
hand-edited. Twenty-four 512x512 frames total 108 KB, and the generator is
pure standard library so nobody needs Pillow to build the app.
The manifest parser rejects three things that would otherwise fail silently and
look plausible:
- A CRS other than EPSG:3857. The map overlays each PNG on a lat/lng quad,
which only lines up if the image is already in Web Mercator; anything else
renders visibly skewed with no error to explain why.
- A missing attribution. The frames are a derived product of CC BY-SA data, so
the credit has to travel with them rather than be remembered at render time.
- Legend stops that do not ascend, which would silently mislabel intensities.
The legend travels in the manifest rather than living as a constant here,
because the worker chose those colours when it rendered the PNGs and a local
copy could drift. RadarLegend.colorFor returns null below the lowest stop:
"no precipitation" has to be transparent, not the first colour of the ramp, or
a dry region renders as drizzle everywhere.
Every failure reaches the caller as a single RadarUnavailableException
regardless of cause, because the app's response is the same in all of them —
hold the last good frame and say how old it is — and branching on cause would
only invite divergence.
ArpaRadarSource is a stub whose every method throws. It is named by the region
config as unavailable and must fail loudly: quietly serving something else
would misreport where the data came from.
Verified: analyze clean, 95 tests passing, including a check that every frame
the manifest lists exists and is a real PNG, and that its bbox matches the
region config.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Creates the app skeleton and the seam everything else in the project hangs
off: region-specific data lives in an asset file, not in code, so adding a
region later is a new JSON file rather than a refactor.
Notable choices:
- applicationId and namespace are it.nuvolari.app rather than the doubled
it.nuvolari.nuvolari that `flutter create` produces, with the Kotlin package
and the iOS bundle identifiers moved to match.
- SDK levels are pinned instead of inherited from `flutter.*`. Google Play
requires API 36, and that is a release blocker rather than something to let a
Flutter upgrade change silently. minSdk 24 is the highest floor the planned
dependencies impose.
- Riverpod and Dio-free for now, no code generation: see docs/stack-decisions.md.
- Italian is the l10n source language, so app_it.arb is the template rather
than a translation of an English original.
The region parser rejects rather than repairs. An inverted bounding box, a map
centre outside its own bounds, an unknown adapter name, a duplicate zone code
or an empty attribution list all throw with the offending field named. Each of
those would otherwise fail silently and visibly wrong: a swapped latitude and
longitude renders the radar in the wrong place, an unknown adapter falling back
to mock would show demo frames where live data was expected, and a missing
attribution is a licence violation rather than a cosmetic gap.
Tests run against the asset that actually ships and against a captured copy of
the live ARPA CAP feed, so the eleven zone codes in the config are checked
against the eleven the feed really emits rather than against a list retyped
from documentation.
Verified: dart format clean, flutter analyze 0 issues, 50 tests passing,
flutter build appbundle --debug produces an AAB with applicationId
it.nuvolari.app, minSdk 24, targetSdk 36.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Alby96andClaude Opus 5