Make catalog feed configuration optional and explicit

src/app/constructCatalog.js

@@ -1,3 +1,4 @@
+import { resolveCatalogSources } from './sourceComposition.js';
 import { createWeatherClock } from '../layers/weather/clock.js';
 import { createWeatherLayer } from '../layers/weather/index.js';
 import { createCyclonesLayer } from '../layers/cyclones/index.js';
@@ -31,33 +32,6 @@ import { localGeoJsonServices } from './localGeojsonServices.js';
 import { createBhoteKoshiEventLayer } from '../data/bhoteKoshiEvent.js';
 import { createBhoteKoshiLocatorLayer } from '../data/bhoteKoshiLocator.js';
 
-const SOURCE_METHODS = Object.freeze({
-  flights: ['getSnapshot'],
-  military: ['getSnapshot'],
-  vessels: ['getSnapshot'],
-  cctv: ['getCatalog', 'getHealth', 'getFrameUrl', 'getMediaUrl'],
-  radio: ['getDirectory', 'recordClick'],
-  traffic: [
-    'requestRoads',
-    'getStatus',
-    'fetchFlowForBounds',
-    'getFlowSessionStats',
-    'resetFlowTileCache',
-  ],
-  bikeshare: ['getStations'],
-  installations: ['getMappedSites', 'searchNearby'],
-  satellites: ['readGroup'],
-  launches: ['getLaunches', 'getActiveTle'],
-  alpr: ['fetch'],
-  firms: ['getSnapshot'],
-  wind: ['getSnapshot'],
-  weather: ['getSnapshot'],
-  cyclones: ['getSnapshot'],
-  earthquakes: ['getSnapshot'],
-  'fire-perimeters': ['getSnapshot'],
-  cables: ['fetch'],
-});
-
 /**
  * Hardware-local layers are registered like any other but never enter share
  * links or stored layer state: another browser cannot have this receiver.
@@ -92,12 +66,8 @@ export function createApplicationCatalog({
   if (!surface?.groundFloor || !surface?.terrain)
     throw new TypeError('Application surface services are required');
 
-  for (const [name, methods] of Object.entries(SOURCE_METHODS)) {
-    if (
-      methods.some((method) => typeof sources?.[name]?.[method] !== 'function')
-    )
-      throw new TypeError(`Invalid catalog source: ${name}`);
-  }
+  const sourceComposition = resolveCatalogSources(sources);
+  sources = sourceComposition.sources;
   const militaryRegistry = createMilitaryRegistry();
   const weatherClock = createWeatherClock();
   const dispose = () => {
@@ -107,7 +77,8 @@ export function createApplicationCatalog({
   };
   signal.addEventListener('abort', dispose, { once: true });
   try {
-    militaryRegistry.configureSource(sources.military, { signal });
+    if (sourceComposition.isConfigured('military'))
+      militaryRegistry.configureSource(sources.military, { signal });
     const flights = createApplicationFlights({
       surface,
       source: sources.flights,
@@ -202,6 +173,7 @@ export function createApplicationCatalog({
       ],
       metadata,
     );
+    sourceComposition.bind(catalog.layers);
     return Object.freeze({
       ...catalog,
       militaryRegistry,

src/app/constructCatalog.test.mjs

@@ -117,7 +117,7 @@ test('invalid or already cancelled construction fails before classification can
   assert.throws(
     () =>
       createApplicationCatalog({
-        sources: {},
+        sources: { flights: {} },
         signal: lifetime.signal,
         surface: fixtureSurface(lifetime.signal),
       }),

src/app/sourceComposition.js

@@ -0,0 +1,101 @@
+const contract = (layers, methods) =>
+  Object.freeze({
+    layers: Object.freeze(layers),
+    methods: Object.freeze(methods),
+  });
+
+/** Acquisition contracts and their consumers; records remain family-specific. */
+export const CATALOG_SOURCE_CONTRACTS = Object.freeze({
+  flights: contract(['flights'], ['getSnapshot']),
+  military: contract(['military'], ['getSnapshot']),
+  vessels: contract(['ais-live-vessels'], ['getSnapshot']),
+  cctv: contract(
+    ['cctv'],
+    ['getCatalog', 'getHealth', 'getFrameUrl', 'getMediaUrl'],
+  ),
+  radio: contract(['radio'], ['getDirectory', 'recordClick']),
+  traffic: contract(
+    ['traffic'],
+    [
+      'requestRoads',
+      'getStatus',
+      'fetchFlowForBounds',
+      'getFlowSessionStats',
+      'resetFlowTileCache',
+    ],
+  ),
+  bikeshare: contract(['bikeshare'], ['getStations']),
+  installations: contract(
+    ['military-installations'],
+    ['getMappedSites', 'searchNearby'],
+  ),
+  satellites: contract(['satellites'], ['readGroup']),
+  launches: contract(['rocket-launches'], ['getLaunches', 'getActiveTle']),
+  alpr: contract(['alpr-cameras'], ['fetch']),
+  firms: contract(['local-firms'], ['getSnapshot']),
+  wind: contract(['wind'], ['getSnapshot']),
+  weather: contract(
+    ['weather-radar', 'weather-satellite', 'weather-lightning'],
+    ['getSnapshot'],
+  ),
+  cyclones: contract(['weather-cyclones'], ['getSnapshot']),
+  earthquakes: contract(['earthquakes'], ['getSnapshot']),
+  'fire-perimeters': contract(['fire-perimeters'], ['getSnapshot']),
+  cables: contract(['telegeography-submarine-cables'], ['fetch']),
+  transit: contract(['transit'], ['requestSnapshot', 'getHistory']),
+});
+
+/** An omitted provider is unavailable, never an authoritative empty dataset. */
+export class SourceUnavailableError extends Error {
+  constructor(name) {
+    super(`Data source not configured: ${name}`);
+    this.name = 'SourceUnavailableError';
+    this.code = 'unavailable';
+    this.unavailable = true;
+    this.retryable = false;
+  }
+}
+
+/** Validate supplied contracts and keep omitted sources inert during construction. */
+export function resolveCatalogSources(supplied = {}) {
+  if (!supplied || typeof supplied !== 'object' || Array.isArray(supplied))
+    throw new TypeError('Catalog sources must be an object');
+  const sources = { ...supplied };
+  const missing = new Set();
+  for (const [name, { methods }] of Object.entries(CATALOG_SOURCE_CONTRACTS)) {
+    const source = sources[name];
+    if (source == null) {
+      missing.add(name);
+      const unavailable = () => {
+        throw new SourceUnavailableError(name);
+      };
+      sources[name] = Object.freeze({
+        label: name,
+        ...Object.fromEntries(methods.map((method) => [method, unavailable])),
+      });
+    } else if (methods.some((method) => typeof source[method] !== 'function')) {
+      throw new TypeError(`Invalid catalog source: ${name}`);
+    }
+  }
+  return {
+    sources,
+    isConfigured: (name) => !missing.has(name),
+    bind(layers) {
+      for (const [name, { layers: ids }] of Object.entries(
+        CATALOG_SOURCE_CONTRACTS,
+      )) {
+        for (const id of ids) {
+          const layer = layers.find((entry) => entry.id === id);
+          if (!layer) throw new Error(`Missing source consumer: ${id}`);
+          layer.getSourceAvailability = () => ({
+            available: !missing.has(name),
+            source: name,
+            reason: missing.has(name)
+              ? `Data source not configured: ${name}`
+              : null,
+          });
+        }
+      }
+    },
+  };
+}

src/app/sourceComposition.test.mjs

@@ -0,0 +1,84 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import {
+  resolveCatalogSources,
+  CATALOG_SOURCE_CONTRACTS,
+} from './sourceComposition.js';
+import { createApplicationCatalog } from './constructCatalog.js';
+import { createSurfaceServices } from './surfaceServices.js';
+import { createStandaloneLayerSources } from '../standalone/layerSources.js';
+import { LayerLifecycle } from '../data/lifecycle.js';
+
+function catalog(sources, t) {
+  const lifetime = new AbortController();
+  t.after(() => lifetime.abort());
+  return createApplicationCatalog({
+    sources,
+    signal: lifetime.signal,
+    surface: createSurfaceServices({
+      terrainSource: { getHeights: async () => [] },
+      signal: lifetime.signal,
+      eventTarget: null,
+    }),
+  });
+}
+
+test('every acquisition source can be omitted without losing catalog membership', (t) => {
+  const baseline = catalog(createStandaloneLayerSources(), t);
+  for (const name of Object.keys(CATALOG_SOURCE_CONTRACTS)) {
+    const sources = createStandaloneLayerSources({ [name]: null });
+    const actual = catalog(sources, t);
+    assert.deepEqual(actual.metadata, baseline.metadata, name);
+    for (const id of CATALOG_SOURCE_CONTRACTS[name].layers) {
+      assert.equal(actual.get(id).getSourceAvailability().available, false, id);
+    }
+  }
+});
+
+test('all acquisition sources may be absent, and enable fails before initializing or fetching', async (t) => {
+  const actual = catalog({}, t);
+  assert.equal(actual.layers.length, 30);
+  const manager = new LayerLifecycle({});
+  for (const layer of actual.layers) manager.register(layer);
+  for (const { layers: ids } of Object.values(CATALOG_SOURCE_CONTRACTS)) {
+    for (const id of ids) {
+      assert.equal(await manager.setEnabled(id, true), false, id);
+      assert.equal(manager.layers.get(id).initialized, false, id);
+      const row = manager.getAll().find((entry) => entry.id === id);
+      assert.equal(row.enabled, false);
+      assert.equal(row.stats.status, 'unavailable');
+      assert.match(row.stats.error, /not configured/);
+    }
+  }
+});
+
+test('configured sources retain identity; invalid implementations never become unavailable silently', () => {
+  const source = { getSnapshot: async () => [] };
+  assert.equal(
+    resolveCatalogSources({ earthquakes: source }).sources.earthquakes,
+    source,
+  );
+  for (const name of Object.keys(CATALOG_SOURCE_CONTRACTS)) {
+    assert.throws(
+      () => resolveCatalogSources({ [name]: {} }),
+      /Invalid catalog source/,
+    );
+  }
+  const missing = resolveCatalogSources({}).sources.earthquakes;
+  assert.throws(() => missing.getSnapshot(), { code: 'unavailable' });
+});
+
+test('standalone defaults allow exact replacements and explicit removal, and reject typos', () => {
+  const source = { getSnapshot: async () => [] };
+  const sources = createStandaloneLayerSources({
+    flights: source,
+    military: null,
+  });
+  assert.equal(sources.flights, source);
+  assert.equal(sources.military, null);
+  assert.equal(typeof sources.cctv.getCatalog, 'function');
+  assert.throws(
+    () => createStandaloneLayerSources({ fligts: source }),
+    /Unknown source/,
+  );
+});