feat(layers): add FAA drone restrictions airspace layer

Show US prohibited and restricted special-use airspace from the keyless
FAA SUA FeatureServer as an off-by-default Infrastructure layer, with
share-link token 3 and an informational-only disclaimer.

src/data/dataCredits.js

@@ -160,6 +160,13 @@ export const DATA_CREDITS = [
       ' · Incident information: ' +
       '<a href="https://inciweb.wildfire.gov/" target="_blank" rel="noopener">InciWeb</a>',
   },
+  {
+    key: 'faa-sua',
+    html:
+      'Drone restrictions: ' +
+      '<a href="https://adds-faa.opendata.arcgis.com/" target="_blank" rel="noopener">FAA Special Use Airspace</a>' +
+      ' (prohibited and restricted zones; informational only)',
+  },
   OSM_CREDIT,
   OPENMAPTILES_CREDIT,
   {

src/data/droneAirspaceProxy.test.mjs

@@ -0,0 +1,146 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { droneAirspaceProxy } from '../../server/providers/droneAirspace.js';
+
+const feature = (id = 310, type = 'P') => ({
+  properties: {
+    NAME: `${type}-${id}`,
+    TYPE_CODE: type,
+    OBJECTID: id,
+    UPPER_DESC: 'TNI',
+  },
+  geometry: {
+    type: 'Polygon',
+    coordinates: [
+      [
+        [-77, 38],
+        [-76, 38],
+        [-76, 39],
+        [-77, 38],
+      ],
+    ],
+  },
+});
+
+function install(options = {}, hook = 'configureServer') {
+  let handler;
+  const plugin = droneAirspaceProxy(options);
+  assert.equal(typeof plugin.configureServer, 'function');
+  assert.equal(typeof plugin.configurePreviewServer, 'function');
+  plugin[hook]({
+    middlewares: {
+      use(path, callback) {
+        assert.equal(path, '/api/drone-airspace');
+        handler = callback;
+      },
+    },
+  });
+  return async (url = '/', method = 'GET', peer = 'local') => {
+    const res = {
+      writeHead(status, headers) {
+        this.status = status;
+        this.headers = headers;
+      },
+      end(body) {
+        this.body = JSON.parse(body);
+      },
+    };
+    await handler({ url, method, socket: { remoteAddress: peer } }, res);
+    return res;
+  };
+}
+
+for (const hook of ['configureServer', 'configurePreviewServer']) {
+  test(`${hook}: paging stops at five pages and normalizes the combined snapshot`, async () => {
+    const calls = [];
+    const request = install(
+      {
+        now: () => 1234,
+        fetchImpl: async (url, options) => {
+          calls.push(new URL(url));
+          assert.ok(options.signal instanceof AbortSignal);
+          assert.equal(options.redirect, 'error');
+          return Response.json({
+            features: [feature(calls.length)],
+            exceededTransferLimit: true,
+          });
+        },
+      },
+      hook,
+    );
+    const res = await request('/?url=https://invalid.example&resultOffset=999');
+    assert.equal(res.status, 200);
+    assert.equal(res.body.fetchedAt, 1234);
+    assert.equal(res.body.rows.length, 5);
+    assert.equal(calls.length, 5);
+    assert.equal(calls[0].searchParams.get('where'), "TYPE_CODE IN ('P','R')");
+    assert.equal(calls[0].searchParams.get('f'), 'geojson');
+    assert.equal(calls[0].searchParams.has('resultOffset'), false);
+    assert.equal(calls[1].searchParams.get('resultOffset'), '1');
+  });
+}
+
+test('a cached snapshot is reused until TTL, then refreshed', async () => {
+  let now = 1000;
+  let fetches = 0;
+  const request = install({
+    now: () => now,
+    fetchImpl: async () => {
+      fetches += 1;
+      return Response.json({ features: [feature(fetches)] });
+    },
+  });
+  const first = await request();
+  now += 3_599_000;
+  const cached = await request();
+  now += 2000;
+  const refreshed = await request();
+  assert.equal(first.body.rows[0].stableId, '1');
+  assert.equal(cached.body.rows[0].stableId, '1');
+  assert.equal(refreshed.body.rows[0].stableId, '2');
+  assert.equal(fetches, 2);
+});
+
+test('a failed refresh serves the last good snapshot as stale', async () => {
+  let now = 1000;
+  let fail = false;
+  const request = install({
+    now: () => now,
+    fetchImpl: async () => {
+      if (fail) return new Response('nope', { status: 503 });
+      return Response.json({ features: [feature(7)] });
+    },
+  });
+  const first = await request();
+  fail = true;
+  now += 3_600_001;
+  const stale = await request();
+  assert.equal(first.status, 200);
+  assert.equal(stale.status, 200);
+  assert.equal(stale.headers['X-Data-Stale'], 'true');
+  assert.equal(stale.body.stale, true);
+  assert.equal(stale.body.rows[0].stableId, '7');
+});
+
+test('method, unknown routes and rate limits are rejected', async () => {
+  const request = install({
+    fetchImpl: async () => Response.json({ features: [feature()] }),
+  });
+  assert.equal((await request('/', 'POST')).status, 405);
+  assert.equal((await request('/nope')).status, 404);
+  const limited = install({
+    fetchImpl: async () => Response.json({ features: [feature()] }),
+  });
+  let last;
+  for (let i = 0; i < 61; i++) last = await limited('/', 'GET', '10.0.0.9');
+  assert.equal(last.status, 429);
+});
+
+test('a cold upstream failure is 502, not an empty snapshot', async () => {
+  const request = install({
+    fetchImpl: async () => new Response('nope', { status: 503 }),
+  });
+  const res = await request();
+  assert.equal(res.status, 502);
+  assert.equal(res.body.error, 'drone_airspace_unavailable');
+});

src/data/layerState.js

@@ -595,6 +595,11 @@ export const LAYER_STATE_REGISTRY = Object.freeze([
     optionOwner: 'cctv',
   }),
   Object.freeze({ id: 'directions', token: 'n', disposition: 'enabled-only' }),
+  Object.freeze({
+    id: 'drone-airspace',
+    token: '3',
+    disposition: 'enabled-only',
+  }),
   Object.freeze({ id: 'earthquakes', token: 'e', disposition: 'enabled-only' }),
   Object.freeze({
     id: 'fire-perimeters',

src/data/layerState.test.mjs

@@ -202,8 +202,8 @@ function encode(state) {
 
 test('production registry is exact, canonical, and rejects incomplete contracts', async () => {
   assert.equal(validateLayerStateRegistry(), true);
-  assert.equal(REGISTERED_LAYER_IDS.length, 29);
-  assert.equal(new Set(REGISTERED_LAYER_IDS).size, 29);
+  assert.equal(REGISTERED_LAYER_IDS.length, 30);
+  assert.equal(new Set(REGISTERED_LAYER_IDS).size, 30);
   assert.ok(REGISTERED_LAYER_IDS.includes('transit'));
   assert.deepEqual(REGISTERED_LAYER_IDS, [...REGISTERED_LAYER_IDS].sort());
   assert.deepEqual(LEGACY_LAYER_STATE_TOKENS, {
@@ -242,7 +242,7 @@ test('production registry is exact, canonical, and rejects incomplete contracts'
   for (const [id, token] of Object.entries(LEGACY_LAYER_STATE_TOKENS)) {
     assert.equal(LAYER_STATE_TOKEN_RESERVATIONS[id], token);
   }
-  assert.equal(nextLayerStateToken(), '3');
+  assert.equal(nextLayerStateToken(), '4');
   assert.equal(
     nextLayerStateToken({
       ...LAYER_STATE_TOKEN_RESERVATIONS,
@@ -307,8 +307,8 @@ test('production registry is exact, canonical, and rejects incomplete contracts'
   assert.equal(
     validateLayerStateAllocations(LAYER_STATE_TOKEN_RESERVATIONS, {
       ...LAYER_STATE_TOKEN_RESERVATIONS,
-      future: '3',
-      next: '4',
+      future: '4',
+      next: '5',
     }),
     true,
   );
@@ -318,7 +318,7 @@ test('production registry is exact, canonical, and rejects incomplete contracts'
         ...LAYER_STATE_TOKEN_RESERVATIONS,
         future: '00',
       }),
-    /next free token 3/,
+    /next free token 4/,
   );
   const beforeLastDigit = { ...digitsExhausted };
   delete beforeLastDigit['prior-9'];
@@ -341,10 +341,10 @@ test('production registry is exact, canonical, and rejects incomplete contracts'
   assert.throws(
     () =>
       validateLayerStateAllocations(
-        { ...LAYER_STATE_TOKEN_RESERVATIONS, merged: '3' },
-        { ...LAYER_STATE_TOKEN_RESERVATIONS, merged: '3', competing: '3' },
+        { ...LAYER_STATE_TOKEN_RESERVATIONS, merged: '4' },
+        { ...LAYER_STATE_TOKEN_RESERVATIONS, merged: '4', competing: '4' },
       ),
-    /next free token 4/,
+    /next free token 5/,
   );
   assert.throws(
     () => validateLayerStateAllocations({ future: '00' }, { future: '01' }),
@@ -2639,6 +2639,22 @@ test('the recent-imagery split is share-link only: never stored locally, and a s
   );
 });
 
+test('drone restrictions uses digit 3 without colliding with fire perimeters', () => {
+  const decoded = decodeLayerStateParams(new URLSearchParams('v=2&l=3.2'));
+  assert.deepEqual(decoded.enabledLayerIds, [
+    'drone-airspace',
+    'fire-perimeters',
+  ]);
+  assert.equal(
+    LAYER_STATE_REGISTRY.find(({ id }) => id === 'drone-airspace').token,
+    '3',
+  );
+  assert.deepEqual(
+    decodeLayerStateParams(new URLSearchParams(encode(decoded))),
+    decoded,
+  );
+});
+
 test('fire perimeters uses digit 2 without colliding with wind or recent imagery', () => {
   const decoded = decodeLayerStateParams(new URLSearchParams('v=2&l=2.k.1'));
   assert.deepEqual(decoded.enabledLayerIds, [

src/data/layerStateTokenLedger.test.mjs

@@ -128,10 +128,14 @@ test('reservation ledger is complete, pinned, and rejects duplicate or malformed
     { ...parseLayerStateTokenReservations(reservationRows) },
     { ...LAYER_STATE_TOKEN_RESERVATIONS },
   );
-  assert.equal(Object.keys(LAYER_STATE_TOKEN_RESERVATIONS).length, 29);
+  assert.equal(Object.keys(LAYER_STATE_TOKEN_RESERVATIONS).length, 30);
   assert.deepEqual(
     { ...LAYER_STATE_TOKEN_RESERVATIONS },
-    { ...LEGACY_LAYER_STATE_TOKENS, 'street-level': '0' },
+    {
+      ...LEGACY_LAYER_STATE_TOKENS,
+      'street-level': '0',
+      'drone-airspace': '3',
+    },
   );
   assert.throws(
     () => parseLayerStateTokenReservations(reservationRows.slice(1)),
@@ -151,9 +155,9 @@ test('reservation ledger is complete, pinned, and rejects duplicate or malformed
     /Duplicate layer-state token reservation/,
   );
   assert.equal(
-    parseLayerStateTokenReservations([...reservationRows, ['future', '3']])
+    parseLayerStateTokenReservations([...reservationRows, ['future', '4']])
       .future,
-    '3',
+    '4',
   );
   assert.throws(
     () =>
@@ -171,14 +175,14 @@ test('reservation ledger is complete, pinned, and rejects duplicate or malformed
 
 test('published retired digits and competing PRs advance the merge-time allocation', () => {
   withPublishedBase(
-    { rows: [...reservationRows, ['retired-layer', '3']] },
+    { rows: [...reservationRows, ['retired-layer', '4']] },
     (cwd) => {
       const published = readPublishedLayerStateReservations('HEAD', cwd);
-      assert.equal(nextLayerStateToken(published), '4');
+      assert.equal(nextLayerStateToken(published), '5');
       assert.equal(
         validateLayerStateAllocations(published, {
           ...published,
-          newcomer: '4',
+          newcomer: '5',
         }),
         true,
       );
@@ -186,15 +190,15 @@ test('published retired digits and competing PRs advance the merge-time allocati
         () =>
           validateLayerStateAllocations(published, {
             ...published,
-            competing: '3',
+            competing: '4',
           }),
-        /next free token 4/,
+        /next free token 5/,
       );
       assert.throws(
         () =>
           validateLayerStateAllocations(published, {
             ...LAYER_STATE_TOKEN_RESERVATIONS,
-            newcomer: '3',
+            newcomer: '4',
           }),
         /changed or removed: retired-layer/,
       );
@@ -202,8 +206,8 @@ test('published retired digits and competing PRs advance the merge-time allocati
   );
 });
 
-test('PR B manually replaces provisional 3 with 4 after PR A publishes 3', () => {
-  withPublishedBase({ rows: [...reservationRows, ['pr-a', '3']] }, (cwd) => {
+test('PR B manually replaces provisional 4 with 5 after PR A publishes 4', () => {
+  withPublishedBase({ rows: [...reservationRows, ['pr-a', '4']] }, (cwd) => {
     mkdirSync(path.join(cwd, 'scripts'));
     const fixtureChecker = path.join(
       cwd,
@@ -224,8 +228,8 @@ test('PR B manually replaces provisional 3 with 4 after PR A publishes 3', () =>
 
     writeCodecFixture(
       cwd,
-      [...reservationRows, ['pr-b', '3']],
-      [{ id: 'pr-b', token: '3' }],
+      [...reservationRows, ['pr-b', '4']],
+      [{ id: 'pr-b', token: '4' }],
     );
     const beforeRebase = runCheck();
     assert.equal(beforeRebase.status, 1);
@@ -233,10 +237,10 @@ test('PR B manually replaces provisional 3 with 4 after PR A publishes 3', () =>
 
     writeCodecFixture(
       cwd,
-      [...reservationRows, ['pr-a', '3'], ['pr-b', '3']],
+      [...reservationRows, ['pr-a', '4'], ['pr-b', '4']],
       [
-        { id: 'pr-a', token: '3' },
-        { id: 'pr-b', token: '3' },
+        { id: 'pr-a', token: '4' },
+        { id: 'pr-b', token: '4' },
       ],
     );
     const staleRebase = runCheck();
@@ -244,16 +248,16 @@ test('PR B manually replaces provisional 3 with 4 after PR A publishes 3', () =>
     assert.match(staleRebase.stderr, /Duplicate layer-state token reservation/);
 
     const published = readPublishedLayerStateReservations('HEAD', cwd);
-    assert.equal(nextLayerStateToken(published), '4');
-    const validBaselineRows = [...reservationRows, ['pr-a', '3']];
-    writeCodecFixture(cwd, validBaselineRows, [{ id: 'pr-a', token: '3' }]);
+    assert.equal(nextLayerStateToken(published), '5');
+    const validBaselineRows = [...reservationRows, ['pr-a', '4']];
+    writeCodecFixture(cwd, validBaselineRows, [{ id: 'pr-a', token: '4' }]);
     const helper = spawnSync(
       process.execPath,
       [realpathSync(fixtureNext), 'pr-b'],
       { cwd, encoding: 'utf8' },
     );
     assert.equal(helper.status, 0, helper.stderr);
-    assert.match(helper.stdout, /pr-b: 4/);
+    assert.match(helper.stdout, /pr-b: 5/);
     assert.deepEqual(
       JSON.parse(readFileSync(path.join(cwd, LEDGER_PATH), 'utf8')),
       validBaselineRows,
@@ -261,20 +265,20 @@ test('PR B manually replaces provisional 3 with 4 after PR A publishes 3', () =>
     );
     writeCodecFixture(
       cwd,
-      [...reservationRows, ['pr-a', '3'], ['pr-b', '4']],
+      [...reservationRows, ['pr-a', '4'], ['pr-b', '5']],
       [
-        { id: 'pr-a', token: '3' },
-        { id: 'pr-b', token: '4' },
+        { id: 'pr-a', token: '4' },
+        { id: 'pr-b', token: '5' },
       ],
     );
     const corrected = runCheck();
     assert.equal(corrected.status, 0, corrected.stderr);
-    assert.match(corrected.stdout, /30 published, 1 new/);
+    assert.match(corrected.stdout, /31 published, 1 new/);
   });
 });
 
 test('allocation batches cross the last digit and base-36 pair boundaries in order', () => {
-  const digitRows = [...'3456789'].map((digit) => [`retired-${digit}`, digit]);
+  const digitRows = [...'456789'].map((digit) => [`retired-${digit}`, digit]);
   const allDigits = parseLayerStateTokenReservations([
     ...reservationRows,
     ...digitRows,
@@ -326,7 +330,7 @@ test('allocation batches cross the last digit and base-36 pair boundaries in ord
 test('an isolated valid two-character fixture round-trips an l field beyond the old 64-character cap', async () => {
   const cwd = mkdtempSync(path.join(tmpdir(), 'gev-layer-token-width-'));
   try {
-    const priorDigits = [...'3456789'].map((digit) => [
+    const priorDigits = [...'456789'].map((digit) => [
       `qa-prior-digit-${digit}`,
       digit,
     ]);
@@ -363,7 +367,7 @@ test('an isolated valid two-character fixture round-trips an l field beyond the
     const params = new URLSearchParams([['v', '2']]);
     codec.encodeLayerStateParams(params, state);
     assert.ok(params.get('l').length > 64, 'fixture must cross the old cap');
-    assert.equal(params.get('l').length, 69);
+    assert.equal(params.get('l').length, 71);
     const restored = codec.decodeLayerStateParams(params);
     assert.deepEqual(restored?.enabledLayerIds, expectedLayerIds);
     assert.deepEqual(restored?.options, state.options);
@@ -381,7 +385,7 @@ test('checker reads a complete future base ledger and rejects retired-token reus
     },
     (cwd) => {
       const published = readPublishedLayerStateReservations('HEAD', cwd);
-      assert.equal(Object.keys(published).length, 30);
+      assert.equal(Object.keys(published).length, 31);
       assert.equal(published['retired-layer'], '00');
       assert.throws(
         () =>

src/data/layerStateTokenReservations.json

@@ -6,6 +6,7 @@
   ["bikeshare", "b"],
   ["cctv", "c"],
   ["directions", "n"],
+  ["drone-airspace", "3"],
   ["earthquakes", "e"],
   ["fire-perimeters", "2"],
   ["flights", "f"],