fix(bikeshare): preserve unknown availability counts

CHANGELOG.md

@@ -74,6 +74,8 @@
 - Tool string length validation counts Unicode characters correctly, including characters outside the basic multilingual plane.
 
 - Director timeline seeks cross the dateline along the short longitude arc.
+- Keep unknown GBFS availability counts neutral instead of turning null or empty
+  values into zero bikes.
 
 - Recent Imagery continues past malformed records in full catalog pages, respects the requested record limit, and reports results as truncated when that limit drops valid records.
 

docs/CURRENT-STATE.md

@@ -1275,6 +1275,9 @@ and stale/error responses remain unchanged. Each has a Node-only package entry
 under `gods-eye-view/server/providers/`. Portable terrain mechanics, traffic tile
 math and GBFS source rules are available under `gods-eye-view/sources/`.
 The browser layers and their rendering remain in their existing modules.
+GBFS null or empty availability counts retain an unknown value through station
+parsing and rendering; they use the neutral station color rather than reporting
+an empty dock. Explicit zero and caller-supplied numeric fallbacks remain valid.
 
 ## Terrain height cache bound
 

src/layers/bikeshare/proxyRoute.test.mjs

@@ -394,3 +394,55 @@ for (const hook of ['configureServer', 'configurePreviewServer']) {
     );
   });
 }
+
+test('unknown GBFS counts stay unknown through the source, model and station color', async () => {
+  const { createRendering } = await import('./rendering.js');
+  const { COLOR_NEUTRAL, COLOR_RED } = await import('./policy.js');
+  for (const missing of [null, '']) {
+    const source = createBikeshareSource({
+      fetchImpl: async () =>
+        Response.json({
+          data: {
+            stations: [
+              {
+                station_id: '2537',
+                num_bikes_available: missing,
+                num_docks_available: 4,
+                is_installed: true,
+                is_renting: true,
+                is_returning: true,
+              },
+            ],
+          },
+        }),
+    });
+    const model = createModel({});
+    const status = model
+      .parseStationStatus(await source.getStations(AUSTIN.stationStatusUrl))
+      .get('2537');
+    const rendering = createRendering({
+      state: {},
+      services: { render: {} },
+      parts: { model },
+    });
+    assert.equal(status.bikesAvailable, null);
+    assert.equal(
+      model.toNonNegativeInteger(status.bikesAvailable),
+      null,
+      'render-map normalization preserves unknown',
+    );
+    assert.equal(rendering.statusToColor(status, 12), COLOR_NEUTRAL);
+    assert.equal(rendering.resolveCapacity(missing, status), 4);
+    assert.equal(
+      rendering.statusToColor({ ...status, bikesAvailable: 0 }, 12),
+      COLOR_RED,
+      'reported zero is still empty',
+    );
+    assert.equal(
+      model.toNonNegativeInteger(missing, 7),
+      7,
+      'caller fallback is preserved',
+    );
+    assert.equal(model.toNonNegativeInteger('3'), 3);
+  }
+});

src/sources/gbfsStations.js

@@ -25,6 +25,7 @@ export function normalizeGbfsBool(value, fallback = true) {
  * @returns {number|null}
  */
 export function toNonNegativeInteger(value, fallback = null) {
+  if (value == null || value === '') return fallback;
   const n = Number(value);
   if (!Number.isFinite(n) || n < 0) return fallback;
   return Math.round(n);