Merge remote-tracking branch 'origin/main' into HEAD

# Conflicts:
#	DATA_SOURCES.md
#	docs/CURRENT-STATE.md
#	server/providers/cctv/constants.js
#	server/providers/cctv/sources.js

src/data/cctvNyc.test.mjs

@@ -0,0 +1,391 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+
+import {
+  loadNycSourcesFromOpenData,
+  nycCameraIsOnline,
+  nycCameraName,
+  nycCameraToSource,
+} from '../../server/providers/cctv/sources.js';
+import {
+  DEFAULT_CCTV_MAX_SOURCES,
+  DEFAULT_NYC_MAX_SOURCES,
+  NYC_CAMERAS_URL,
+  NYC_GROUND_ELEVATION_M,
+  NYC_IMAGE_ORIGIN,
+  NYC_IMAGE_URL,
+  NYC_MAX_CATALOG_BYTES,
+} from '../../server/providers/cctv/constants.js';
+import {
+  CAMERA_CODE_MAX_CHARS,
+  isLikelyNycCoordinate,
+} from '../../server/providers/cctv/normalize.js';
+import { createCctvCatalog } from '../../server/providers/cctv/catalog.js';
+
+/**
+ * A response whose body is a live stream, plus a flag that flips when the
+ * stream is cancelled. A rejection path that returns without cancelling holds
+ * the transport open, so the flag is what the refusal tests actually assert.
+ */
+const streamingResponse = (init = {}) => {
+  const state = { cancelled: false };
+  const body = new ReadableStream({
+    start(controller) {
+      controller.enqueue(new TextEncoder().encode('['));
+    },
+    cancel() {
+      state.cancelled = true;
+    },
+  });
+  return { response: new Response(body, init), state };
+};
+
+const MIDTOWN_ID = '8a6bc417-4877-4ebe-8052-88c1b261baf1';
+const BROOKLYN_ID = '11111111-2222-3333-4444-555555555555';
+
+/** One TMC camera row, shaped like the live `webcams.nyctmc.org` payload. */
+const row = (overrides = {}) => ({
+  id: MIDTOWN_ID,
+  name: 'Central Park West @ 86 St',
+  latitude: 40.785302,
+  longitude: -73.969353,
+  area: 'Manhattan',
+  isOnline: 'true',
+  imageUrl: NYC_IMAGE_URL(MIDTOWN_ID),
+  ...overrides,
+});
+
+test('a NYC row maps to a source on the pinned HTTPS frame host', () => {
+  const source = nycCameraToSource(row());
+  assert.equal(source.id, `nyc-${MIDTOWN_ID}`);
+  assert.equal(source.name, 'Central Park West @ 86 St');
+  assert.equal(source.city, 'Manhattan');
+  assert.equal(source.cityId, 'nyc');
+  assert.equal(source.provider, 'NYC DOT Traffic Management Center');
+  assert.equal(source.lat, 40.785302);
+  assert.equal(source.lon, -73.969353);
+  assert.equal(source.feedType, 'image');
+  assert.equal(source.sourceKind, 'nyc-dot-tmc');
+  assert.equal(
+    source.license,
+    'Public NYC DOT Traffic Management Center traffic camera',
+  );
+  assert.equal(source.groundElevationM, NYC_GROUND_ELEVATION_M);
+  assert.equal(source.url, NYC_IMAGE_URL(MIDTOWN_ID));
+  assert.equal(source.url, source.snapshotUrl);
+  assert.ok(source.url.startsWith(NYC_IMAGE_ORIGIN));
+  assert.equal(source.headingConfidence, 'low');
+  assert.ok(Number.isFinite(source.headingDeg));
+});
+
+test('frame URLs are synthesized from the UUID; the payload URL is ignored', () => {
+  const source = nycCameraToSource(
+    row({ imageUrl: 'https://evil.example/cameras/x/image' }),
+  );
+  assert.equal(source.url, NYC_IMAGE_URL(MIDTOWN_ID));
+  assert.equal(source.snapshotUrl, source.url);
+});
+
+test('offline cameras, off-city geometry and unusable ids are dropped', () => {
+  assert.equal(nycCameraToSource(row({ isOnline: 'false' })), null);
+  assert.equal(nycCameraToSource(row({ isOnline: false })), null);
+  assert.equal(
+    nycCameraToSource(row({ isOnline: 'TRUE' })).id,
+    `nyc-${MIDTOWN_ID}`,
+  );
+  assert.equal(
+    nycCameraToSource(row({ isOnline: true })).id,
+    `nyc-${MIDTOWN_ID}`,
+  );
+  // Austin: a plausible lat/lon, but not a New York camera.
+  assert.equal(
+    nycCameraToSource(row({ latitude: 30.2672, longitude: -97.7431 })),
+    null,
+  );
+  assert.equal(nycCameraToSource(row({ latitude: 0, longitude: 0 })), null);
+  assert.equal(nycCameraToSource(row({ id: '../etc/passwd' })), null);
+  assert.equal(nycCameraToSource(row({ id: 'not-a-uuid' })), null);
+  assert.equal(nycCameraToSource(row({ id: `${MIDTOWN_ID}/../x` })), null);
+  assert.equal(nycCameraToSource(null), null);
+});
+
+test('ids lower-case the UUID and unknown boroughs fall back to New York', () => {
+  const mixed = nycCameraToSource(
+    row({ id: MIDTOWN_ID.toUpperCase(), area: 'Long Island' }),
+  );
+  assert.equal(mixed.id, `nyc-${MIDTOWN_ID}`);
+  assert.equal(mixed.city, 'New York');
+  assert.equal(
+    mixed.url,
+    NYC_IMAGE_URL(MIDTOWN_ID.toUpperCase()),
+    'the registered frame path keeps the catalog UUID spelling',
+  );
+});
+
+test('a nameless row still gets a label', () => {
+  assert.equal(
+    nycCameraName({ name: '  FDR Drive @ 23 St ' }, 'nyc-x'),
+    'FDR Drive @ 23 St',
+  );
+  assert.equal(nycCameraName({}, `nyc-${MIDTOWN_ID}`), 'NYC Camera 8a6bc417');
+  assert.equal(nycCameraIsOnline('true'), true);
+  assert.equal(nycCameraIsOnline('false'), false);
+});
+
+test('the unselected label is the intersection, trimmed to the code width', () => {
+  assert.equal(nycCameraToSource(row()).code, 'CENTRAL PARK WEST @ 86 ST');
+  const long = nycCameraToSource(
+    row({
+      name: 'Brooklyn Queens Expressway @ Atlantic Avenue / Flatbush Avenue Extension',
+    }),
+  );
+  assert.ok(long.code.length <= CAMERA_CODE_MAX_CHARS);
+  assert.ok(long.code.endsWith('…'));
+  assert.ok(long.code.startsWith('BROOKLYN'));
+});
+
+test('the loader reads the keyless catalog and collapses duplicate ids', async (t) => {
+  t.mock.method(console, 'log', () => {});
+  const requested = [];
+  t.mock.method(globalThis, 'fetch', async (url, init) => {
+    requested.push([String(url), init.redirect]);
+    return Response.json([
+      row({ latitude: 40.758, longitude: -73.9855 }),
+      row({
+        name: 'Central Park West @ 86 St (duplicate)',
+        latitude: 40.758,
+        longitude: -73.9855,
+      }),
+      row({
+        id: BROOKLYN_ID,
+        name: 'Atlantic Ave @ Flatbush Ave',
+        latitude: 40.65,
+        longitude: -73.96,
+        area: 'Brooklyn',
+        imageUrl: NYC_IMAGE_URL(BROOKLYN_ID),
+      }),
+      row({ isOnline: 'false', name: 'Offline camera' }),
+      row({ id: 'https://evil.example/x' }),
+    ]);
+  });
+  const cameras = await loadNycSourcesFromOpenData();
+  assert.deepEqual(requested, [[NYC_CAMERAS_URL, 'manual']]);
+  assert.deepEqual(
+    cameras.map((camera) => camera.id),
+    // Nearest to a borough anchor first: the Times Square camera before Brooklyn.
+    [`nyc-${MIDTOWN_ID}`, `nyc-${BROOKLYN_ID}`],
+  );
+  assert.equal(cameras[0].name, 'Central Park West @ 86 St');
+  assert.equal(cameras[1].city, 'Brooklyn');
+});
+
+test('an upstream failure yields an empty pack and releases the response', async (t) => {
+  t.mock.method(console, 'warn', () => {});
+  const failed = streamingResponse({ status: 503 });
+  t.mock.method(globalThis, 'fetch', async () => failed.response);
+  assert.deepEqual(await loadNycSourcesFromOpenData(), []);
+  assert.equal(failed.state.cancelled, true, 'the failed body is cancelled');
+
+  t.mock.restoreAll();
+  t.mock.method(console, 'warn', () => {});
+  t.mock.method(globalThis, 'fetch', async () => {
+    throw new Error('network down');
+  });
+  assert.deepEqual(await loadNycSourcesFromOpenData(), []);
+});
+
+test('the catalog fetch refuses redirects and oversized bodies', async (t) => {
+  t.mock.method(console, 'warn', () => {});
+  const seen = [];
+  const redirected = streamingResponse({
+    status: 302,
+    headers: { location: 'https://evil.example/cameras.json' },
+  });
+  t.mock.method(globalThis, 'fetch', async (url, init) => {
+    seen.push([String(url), init.redirect]);
+    return redirected.response;
+  });
+  assert.deepEqual(await loadNycSourcesFromOpenData(), []);
+  assert.deepEqual(seen, [[NYC_CAMERAS_URL, 'manual']]);
+  assert.equal(
+    redirected.state.cancelled,
+    true,
+    'the redirect body is cancelled',
+  );
+
+  t.mock.restoreAll();
+  t.mock.method(console, 'warn', () => {});
+  t.mock.method(globalThis, 'fetch', async () => {
+    const body = JSON.stringify([row()]);
+    return new Response(body, {
+      headers: {
+        'Content-Type': 'application/json',
+        'content-length': String(NYC_MAX_CATALOG_BYTES + 1),
+      },
+    });
+  });
+  assert.deepEqual(await loadNycSourcesFromOpenData(), []);
+
+  t.mock.restoreAll();
+  t.mock.method(console, 'warn', () => {});
+  t.mock.method(globalThis, 'fetch', async () => {
+    const oversized = 'x'.repeat(NYC_MAX_CATALOG_BYTES + 1024);
+    return new Response(
+      new ReadableStream({
+        start(controller) {
+          controller.enqueue(new TextEncoder().encode(oversized));
+          controller.close();
+        },
+      }),
+      { headers: { 'Content-Type': 'application/json' } },
+    );
+  });
+  assert.deepEqual(await loadNycSourcesFromOpenData(), []);
+});
+
+test('a reduced pack cap keeps cameras nearest the borough anchors', async (t) => {
+  t.mock.method(console, 'log', () => {});
+  const saved = process.env.CCTV_NYC_MAX_SOURCES;
+  t.after(() => {
+    if (saved === undefined) delete process.env.CCTV_NYC_MAX_SOURCES;
+    else process.env.CCTV_NYC_MAX_SOURCES = saved;
+  });
+  process.env.CCTV_NYC_MAX_SOURCES = '8';
+  const rows = [
+    // Far southern Staten Island, listed first so only distance can keep them.
+    ...[40.5, 40.505, 40.51, 40.515, 40.52, 40.525].map((lat, i) =>
+      row({
+        id: `aaaaaaaa-bbbb-cccc-dddd-${String(i).padStart(12, '0')}`,
+        latitude: lat,
+        longitude: -74.24,
+        area: 'Staten Island',
+        name: `SI ${i}`,
+      }),
+    ),
+    ...[40.758, 40.757, 40.756, 40.755, 40.754, 40.753].map((lat, i) =>
+      row({
+        id: `bbbbbbbb-cccc-dddd-eeee-${String(i).padStart(12, '0')}`,
+        latitude: lat,
+        longitude: -73.9855,
+        area: 'Manhattan',
+        name: `Midtown ${i}`,
+      }),
+    ),
+  ];
+  t.mock.method(globalThis, 'fetch', async () => Response.json(rows));
+  const cameras = await loadNycSourcesFromOpenData();
+  assert.equal(cameras.length, 8);
+  assert.deepEqual(
+    cameras.map((camera) => camera.city),
+    [
+      'Manhattan',
+      'Manhattan',
+      'Manhattan',
+      'Manhattan',
+      'Manhattan',
+      'Manhattan',
+      'Staten Island',
+      'Staten Island',
+    ],
+    'Midtown fills first; the Staten Island anchor still keeps a share',
+  );
+});
+
+/**
+ * Serve the NYC catalog to the NYC endpoint and an empty payload to every
+ * other pack, so one catalog refresh exercises the registration without
+ * reaching the network.
+ */
+const runCatalogWithMockedUpstreams = async (t) => {
+  const requested = [];
+  t.mock.method(console, 'log', () => {});
+  t.mock.method(console, 'warn', () => {});
+  t.mock.method(globalThis, 'fetch', async (url) => {
+    const href = String(url);
+    requested.push(href);
+    if (href === NYC_CAMERAS_URL) {
+      return Response.json([
+        row({ latitude: 40.758, longitude: -73.9855 }),
+        row({
+          id: BROOKLYN_ID,
+          name: 'Atlantic Ave @ Flatbush Ave',
+          latitude: 40.65,
+          longitude: -73.96,
+          area: 'Brooklyn',
+        }),
+      ]);
+    }
+    return Response.json([]);
+  });
+  const sources = await createCctvCatalog({ sourceRoot: '/nonexistent' })();
+  return { requested, sources };
+};
+
+/** Run one catalog refresh with CCTV_NYC_ENABLED set to `flag` (undefined
+ * leaves it unset), restoring the environment afterwards. */
+const runCatalogWithNycFlag = async (t, flag) => {
+  const saved = { ...process.env };
+  try {
+    delete process.env.CCTV_SOURCES_FILE;
+    delete process.env.CCTV_SOURCES_JSON;
+    if (flag === undefined) delete process.env.CCTV_NYC_ENABLED;
+    else process.env.CCTV_NYC_ENABLED = flag;
+    return await runCatalogWithMockedUpstreams(t);
+  } finally {
+    for (const key of Object.keys(process.env)) {
+      if (!(key in saved)) delete process.env[key];
+    }
+    Object.assign(process.env, saved);
+  }
+};
+
+test('CCTV_NYC_ENABLED=1 wires the NYC lane into the catalog', async (t) => {
+  const { requested, sources } = await runCatalogWithNycFlag(t, '1');
+  assert.ok(
+    requested.includes(NYC_CAMERAS_URL),
+    'the catalog refresh invokes the NYC loader',
+  );
+  assert.deepEqual(
+    sources.filter((s) => s.cityId === 'nyc').map((s) => s.id),
+    [`nyc-${MIDTOWN_ID}`, `nyc-${BROOKLYN_ID}`],
+    'NYC cameras reach the served catalog through the registered lane',
+  );
+});
+
+// NYC DOT requires a data-sharing agreement for this feed, so an install that
+// has not opted in must never contact it.
+for (const [label, flag] of [
+  ['an unset CCTV_NYC_ENABLED', undefined],
+  ['an empty CCTV_NYC_ENABLED', ''],
+  ['CCTV_NYC_ENABLED=0', '0'],
+  ['CCTV_NYC_ENABLED=true', 'true'],
+]) {
+  test(`${label} makes no NYC request`, async (t) => {
+    const { requested, sources } = await runCatalogWithNycFlag(t, flag);
+    assert.ok(requested.length > 0, 'the other packs still refreshed');
+    assert.equal(
+      requested.some((href) => href.includes('nyctmc.org')),
+      false,
+      'the lane never reaches its upstream',
+    );
+    assert.deepEqual(
+      sources.filter((s) => s.cityId === 'nyc'),
+      [],
+    );
+  });
+}
+
+test('the shipped catalog ceiling is not raised to make room for this pack', () => {
+  assert.equal(DEFAULT_CCTV_MAX_SOURCES, 4000);
+  assert.equal(DEFAULT_NYC_MAX_SOURCES, 250);
+});
+
+test('isLikelyNycCoordinate spans the five boroughs and rejects the rest', () => {
+  assert.equal(isLikelyNycCoordinate(40.758, -73.9855), true); // Times Square
+  assert.equal(isLikelyNycCoordinate(40.5795, -74.1502), true); // Staten Island
+  assert.equal(isLikelyNycCoordinate(40.8448, -73.8648), true); // Bronx
+  assert.equal(isLikelyNycCoordinate(40.5077, -74.2304), true); // southern SI slack
+  assert.equal(isLikelyNycCoordinate(30.2672, -97.7431), false); // Austin
+  assert.equal(isLikelyNycCoordinate(0, 0), false);
+  assert.equal(isLikelyNycCoordinate(NaN, -73.98), false);
+});

src/data/dataCredits.js

@@ -91,6 +91,13 @@ export function hideOsmCredit(viewer, owner) {
   return true;
 }
 
+/** NYC DOT asks every application that uses its data to carry this
+ * disclaimer verbatim (nyc.gov/html/dot/html/about/datafeeds.shtml). */
+export const NYC_DOT_DISCLAIMER =
+  'This application may contain and/or utilize information which was originally compiled by the New York City Department of Transportation (NYC DOT) for governmental purposes; the information may subsequently been modified by entity/entities other than NYC DOT. ' +
+  'NYC DOT and the City of New York make no representation as to the accuracy or usefulness of the information provided by this application or the information's suitability for any purpose and disclaim any liability for omissions or errors that may be contained therein. ' +
+  'The public is advised to observe posted signage for compliance with applicable laws and regulations.';
+
 export const DATA_CREDITS = [
   // ── Live sources ────────────────────────────────────────────────
   {
@@ -249,6 +256,13 @@ export const DATA_CREDITS = [
       '<a href="https://kartverket.no/en/api-and-data/terrengdata" target="_blank" rel="noopener">Kartverket</a> ' +
       '(<a href="https://creativecommons.org/licenses/by/4.0/" target="_blank" rel="noopener">CC BY 4.0</a>)',
   },
+  {
+    key: 'nyc-cctv',
+    html:
+      'CCTV cameras &amp; frames (New York City, when enabled): ' +
+      '<a href="https://webcams.nyctmc.org/" target="_blank" rel="noopener">NYC DOT Traffic Management Center</a>. ' +
+      NYC_DOT_DISCLAIMER,
+  },
   {
     key: 'gbfs',
     html: 'Bikeshare availability: GBFS operator feeds (e.g. Austin BCycle)',

src/data/dataCredits.test.mjs

@@ -1,6 +1,6 @@
 import { test } from 'node:test';
 import assert from 'node:assert/strict';
-import { DATA_CREDITS } from './dataCredits.js';
+import { DATA_CREDITS, NYC_DOT_DISCLAIMER } from './dataCredits.js';
 
 test('every credit carries a unique key and some markup to render', () => {
   const keys = DATA_CREDITS.map((entry) => entry.key);
@@ -120,3 +120,11 @@ test('tile attribution follows source changes and viewers have independent owner
   assert.equal(a.credits.size, 0);
   assert.equal(b.credits.size, 1);
 });
+
+test('the NYC camera credit carries NYC DOT’s requested disclaimer', () => {
+  const credit = DATA_CREDITS.find((entry) => entry.key === 'nyc-cctv');
+  assert.ok(credit, 'NYC DOT camera frames must be credited');
+  assert.ok(credit.html.includes(NYC_DOT_DISCLAIMER));
+  assert.match(credit.html, /make no representation as to the accuracy/);
+  assert.match(credit.html, /observe posted signage/);
+});

src/data/layerState.test.mjs

@@ -2703,13 +2703,19 @@ test('Street Level: the link codec accepts exactly the windows the filter keeps'
   assert.equal(streetLevelOptions('0.s.3652').sinceDays, 3652);
 });
 
-test('Street Level: a link without the provider switch keeps Mapillary on', () => {
+test('Street Level: a link without the provider switches keeps Mapillary on and Street View off', () => {
   assert.deepEqual(streetLevelOptions(''), {
     mapillary: true,
     providerSwitches: '',
     pano: 'all',
     sinceDays: 0,
   });
+  // Street View rides the shared provider-switch field, off unless lit.
+  assert.equal(streetLevelOptions('0.r.google-1').providerSwitches, 'google-1');
+  assert.equal(
+    createDefaultLayerState().options['street-level'].providerSwitches,
+    '',
+  );
   assert.equal(streetLevelOptions('0.p.f').mapillary, true);
   assert.equal(streetLevelOptions('0.m.0').mapillary, false);
   assert.equal(

src/data/scenePick.js

@@ -47,3 +47,52 @@ export function isPickedWorldPosition(position) {
   const magnitude = Math.hypot(x, y, z);
   return magnitude >= MIN_PICK_MAGNITUDE_M && magnitude <= MAX_PICK_MAGNITUDE_M;
 }
+
+/**
+ * The world position under a screen point: the rendered surface where the
+ * depth buffer has it, else the ellipsoid; null over the sky.
+ *
+ * @param {object} viewer A Cesium viewer.
+ * @param {{x: number, y: number}} screenPosition
+ * @returns {{x: number, y: number, z: number}|null} A Cartesian3.
+ */
+export function pickGroundPosition(viewer, screenPosition) {
+  const scene = viewer?.scene;
+  let position = null;
+  if (
+    scene?.pickPositionSupported &&
+    typeof scene.pickPosition === 'function'
+  ) {
+    try {
+      position = scene.pickPosition(screenPosition);
+    } catch {
+      position = null;
+    }
+  }
+  if (
+    !isPickedWorldPosition(position) &&
+    typeof viewer?.camera?.pickEllipsoid === 'function'
+  ) {
+    try {
+      position = viewer.camera.pickEllipsoid(screenPosition);
+    } catch {
+      position = null;
+    }
+  }
+  return isPickedWorldPosition(position) ? position : null;
+}
+
+/**
+ * Whether a `scene.pick()` result is the map itself: nothing, or 3D tile
+ * content (which has no id).
+ *
+ * @param {object|null|undefined} picked
+ * @returns {boolean}
+ */
+export function isSurfacePick(picked) {
+  if (!picked) return true;
+  if (picked.id !== undefined) return false;
+  return (
+    picked.content !== undefined || picked.primitive?.isCesium3DTileset === true
+  );
+}

src/data/scenePick.test.mjs

@@ -3,9 +3,8 @@ import assert from 'node:assert/strict';
 import * as Cesium from 'cesium';
 import { isPickedWorldPosition } from './scenePick.js';
 
-const describe = (position) => (position
-  ? `(${position.x}, ${position.y}, ${position.z})`
-  : String(position));
+const describe = (position) =>
+  position ? `(${position.x}, ${position.y}, ${position.z})` : String(position);
 
 test('a degenerate depth pick is rejected before it reaches Cesium', () => {
   // These are the shapes `scene.pickPosition()` can produce when the depth read
@@ -21,7 +20,11 @@ test('a degenerate depth pick is rejected before it reaches Cesium', () => {
     new Cesium.Cartesian3(0.2, -0.3, 0.1),
   ];
   for (const position of degenerate) {
-    assert.equal(isPickedWorldPosition(position), false, `must reject ${describe(position)}`);
+    assert.equal(
+      isPickedWorldPosition(position),
+      false,
+      `must reject ${describe(position)}`,
+    );
   }
 });
 
@@ -38,11 +41,18 @@ test('the guard is an Earth-sized band, not just a non-zero check', () => {
     new Cesium.Cartesian3(0, 0, 5_999_999),
   ];
   for (const position of belowTheFloor) {
-    assert.equal(isPickedWorldPosition(position), false, `must reject ${describe(position)}`);
+    assert.equal(
+      isPickedWorldPosition(position),
+      false,
+      `must reject ${describe(position)}`,
+    );
     // Each one converts WITHOUT throwing — that is exactly what makes it dangerous.
     const carto = Cesium.Cartographic.fromCartesian(position);
     assert.ok(carto, `Cesium converts ${describe(position)} without complaint`);
-    assert.ok(carto.height < -300_000, 'and puts the "target" hundreds of km underground');
+    assert.ok(
+      carto.height < -300_000,
+      'and puts the "target" hundreds of km underground',
+    );
   }
 
   const aboveTheCeiling = [
@@ -52,7 +62,11 @@ test('the guard is an Earth-sized band, not just a non-zero check', () => {
     new Cesium.Cartesian3(1e155, 0, 0),
   ];
   for (const position of aboveTheCeiling) {
-    assert.equal(isPickedWorldPosition(position), false, `must reject ${describe(position)}`);
+    assert.equal(
+      isPickedWorldPosition(position),
+      false,
+      `must reject ${describe(position)}`,
+    );
   }
   assert.throws(
     () => Cesium.Cartographic.fromCartesian(new Cesium.Cartesian3(1e155, 0, 0)),
@@ -61,8 +75,14 @@ test('the guard is an Earth-sized band, not just a non-zero check', () => {
   );
 
   // Both edges of the band are inclusive, and both are real magnitudes.
-  assert.equal(isPickedWorldPosition(new Cesium.Cartesian3(6_000_000, 0, 0)), true);
-  assert.equal(isPickedWorldPosition(new Cesium.Cartesian3(1_000_000_000, 0, 0)), true);
+  assert.equal(
+    isPickedWorldPosition(new Cesium.Cartesian3(6_000_000, 0, 0)),
+    true,
+  );
+  assert.equal(
+    isPickedWorldPosition(new Cesium.Cartesian3(1_000_000_000, 0, 0)),
+    true,
+  );
 });
 
 test('a real picked position is accepted', () => {
@@ -81,13 +101,22 @@ test('a real picked position is accepted', () => {
     Cesium.Cartesian3.fromDegrees(0, 0, 35_786_000),
   ];
   for (const position of real) {
-    assert.equal(isPickedWorldPosition(position), true, `must accept ${describe(position)}`);
+    assert.equal(
+      isPickedWorldPosition(position),
+      true,
+      `must accept ${describe(position)}`,
+    );
   }
 
   // The floor has real margin under the smallest legitimate magnitude, so no
   // plausible pick sits anywhere near the boundary.
-  const polarSurface = Cesium.Cartesian3.magnitude(Cesium.Cartesian3.fromDegrees(0, 90, -10_935));
-  assert.ok(polarSurface > 6_300_000, `smallest real magnitude was ${polarSurface}`);
+  const polarSurface = Cesium.Cartesian3.magnitude(
+    Cesium.Cartesian3.fromDegrees(0, 90, -10_935),
+  );
+  assert.ok(
+    polarSurface > 6_300_000,
+    `smallest real magnitude was ${polarSurface}`,
+  );
 });
 
 test('the guard rejects each way Cesium mishandles a degenerate pick', () => {
@@ -118,7 +147,10 @@ test('the guard rejects each way Cesium mishandles a degenerate pick', () => {
   //    Earth's core. That is the quietest failure of the three and the reason
   //    the guard needs a magnitude band, not just a finiteness check.
   const nearCenter = new Cesium.Cartesian3(0.2, -0.3, 0.1);
-  assert.ok(Cesium.Cartographic.fromCartesian(nearCenter), 'Cesium converts it without complaint');
+  assert.ok(
+    Cesium.Cartographic.fromCartesian(nearCenter),
+    'Cesium converts it without complaint',
+  );
   assert.equal(isPickedWorldPosition(nearCenter), false);
 
   // …and every position the guard accepts must convert to the right place.
@@ -129,3 +161,26 @@ test('the guard rejects each way Cesium mishandles a degenerate pick', () => {
   assert.ok(Math.abs(Cesium.Math.toDegrees(carto.longitude) + 97.7431) < 1e-6);
   assert.ok(Math.abs(Cesium.Math.toDegrees(carto.latitude) - 30.2672) < 1e-6);
 });
+
+test('the ground under a click: the rendered surface, else the ellipsoid, never the sky', async () => {
+  const { pickGroundPosition } = await import('./scenePick.js');
+  const ground = { x: 6378137, y: 0, z: 0 };
+  const sky = { x: 500, y: 0, z: 0 };
+  const viewer = (picked, ellipsoid) => ({
+    scene: { pickPositionSupported: true, pickPosition: () => picked },
+    camera: { pickEllipsoid: () => ellipsoid },
+  });
+  assert.equal(pickGroundPosition(viewer(ground, null), {}), ground);
+  assert.equal(pickGroundPosition(viewer(sky, ground), {}), ground);
+  assert.equal(pickGroundPosition(viewer(undefined, undefined), {}), null);
+  assert.equal(pickGroundPosition(null, {}), null);
+});
+
+test('a surface pick is nothing, or Google 3D tile content without an id', async () => {
+  const { isSurfacePick } = await import('./scenePick.js');
+  assert.equal(isSurfacePick(undefined), true);
+  assert.equal(isSurfacePick({ content: {} }), true);
+  assert.equal(isSurfacePick({ primitive: { isCesium3DTileset: true } }), true);
+  assert.equal(isSurfacePick({ id: 'flight:1', content: {} }), false);
+  assert.equal(isSurfacePick({ primitive: {} }), false, 'an unnamed primitive');
+});