Persist explicit provider toggles through the layer state coordinator

src/data/idSwitches.js

@@ -45,3 +45,19 @@ export function decodeIdSwitches(value) {
       : [],
   );
 }
+
+/** Persist only explicitly requested switch IDs, not unrelated live changes. */
+export function patchRequestedIdSwitches(previous, applied, requested) {
+  const current = decodeIdSwitches(applied);
+  const next = new Map(
+    [...decodeIdSwitches(previous)].filter(([id]) => current.has(id)),
+  );
+  let changed = false;
+  for (const [id, on] of current) {
+    if (Object.hasOwn(requested, id) && typeof requested[id] === 'boolean') {
+      next.set(id, on);
+      changed = true;
+    }
+  }
+  return changed ? encodeIdSwitches(next) : undefined;
+}

src/data/layerState.js

@@ -1,4 +1,4 @@
-import { normalizeIdSwitches } from './idSwitches.js';
+import { normalizeIdSwitches, patchRequestedIdSwitches } from './idSwitches.js';
 import reservationRows from './layerStateTokenReservations.json' with { type: 'json' };
 
 const VALID_DISPOSITIONS = new Set([
@@ -416,6 +416,7 @@ const OPTION_GROUPS = Object.freeze({
     booleanOption('mapillary', 'm', true),
     Object.freeze({
       key: 'providerSwitches',
+      patchRequested: patchRequestedIdSwitches,
       token: 'r',
       defaultValue: '',
       normalize: (value) => normalizeIdSwitches(value, ['mapillary']),

src/data/layerState.test.mjs

@@ -1,3 +1,4 @@
+import { encodeParams, decodeParams } from '../layers/streetLevel/params.js';
 import { readShellSource } from '../testSupport/readShellSource.mjs';
 import { expandApplicationHtml } from '../../build/application-html.js';
 import { readLayerSource } from '../testSupport/readLayerSource.mjs';
@@ -243,7 +244,11 @@ test('production registry is exact, canonical, and rejects incomplete contracts'
   }
   assert.equal(nextLayerStateToken(), '3');
   assert.equal(
-    nextLayerStateToken({ ...LAYER_STATE_TOKEN_RESERVATIONS, alpha: '3', bravo: '4' }),
+    nextLayerStateToken({
+      ...LAYER_STATE_TOKEN_RESERVATIONS,
+      alpha: '3',
+      bravo: '4',
+    }),
     '5',
   );
   const digitsExhausted = {
@@ -276,7 +281,9 @@ test('production registry is exact, canonical, and rejects incomplete contracts'
           [
             ...'0123456789',
             ...[...LAYER_STATE_TOKEN_ALPHABET].flatMap((first) =>
-              [...LAYER_STATE_TOKEN_ALPHABET].map((second) => `${first}${second}`),
+              [...LAYER_STATE_TOKEN_ALPHABET].map(
+                (second) => `${first}${second}`,
+              ),
             ),
           ].map((token, index) => [`occupied-${index}`, token]),
         ),
@@ -298,33 +305,37 @@ test('production registry is exact, canonical, and rejects incomplete contracts'
     true,
   );
   assert.equal(
-    validateLayerStateAllocations(
-      LAYER_STATE_TOKEN_RESERVATIONS,
-      { ...LAYER_STATE_TOKEN_RESERVATIONS, future: '3', next: '4' },
-    ),
+    validateLayerStateAllocations(LAYER_STATE_TOKEN_RESERVATIONS, {
+      ...LAYER_STATE_TOKEN_RESERVATIONS,
+      future: '3',
+      next: '4',
+    }),
     true,
   );
   assert.throws(
-    () => validateLayerStateAllocations(LAYER_STATE_TOKEN_RESERVATIONS, {
-      ...LAYER_STATE_TOKEN_RESERVATIONS,
-      future: '00',
-    }),
+    () =>
+      validateLayerStateAllocations(LAYER_STATE_TOKEN_RESERVATIONS, {
+        ...LAYER_STATE_TOKEN_RESERVATIONS,
+        future: '00',
+      }),
     /next free token 3/,
   );
   const beforeLastDigit = { ...digitsExhausted };
   delete beforeLastDigit['prior-9'];
   assert.equal(
-    validateLayerStateAllocations(
-      beforeLastDigit,
-      { ...beforeLastDigit, futurePair: '00', futureDigit: '9' },
-    ),
+    validateLayerStateAllocations(beforeLastDigit, {
+      ...beforeLastDigit,
+      futurePair: '00',
+      futureDigit: '9',
+    }),
     true,
   );
   assert.equal(
-    validateLayerStateAllocations(
-      digitsExhausted,
-      { ...digitsExhausted, pairB: '01', pairA: '00' },
-    ),
+    validateLayerStateAllocations(digitsExhausted, {
+      ...digitsExhausted,
+      pairB: '01',
+      pairA: '00',
+    }),
     true,
   );
   assert.throws(
@@ -2706,3 +2717,73 @@ test('Street Level: a link without the provider switch keeps Mapillary on', () =
     true,
   );
 });
+
+test('explicit provider switches reach durable state without adopting unrelated live switches', () => {
+  const manager = new DataLayerManager({});
+  const providers = new Map([
+    ['mapillary', true],
+    ['alpha', true],
+    ['beta', true],
+  ]);
+  const filter = { pano: 'all', sinceDays: 0 };
+  for (const id of REGISTERED_LAYER_IDS) {
+    manager.register(
+      id === 'street-level'
+        ? {
+            ...fakeLayer(id),
+            getParams: () => encodeParams({ providers, filter }),
+            setParams(params) {
+              const decoded = decodeParams(params, {
+                providerIds: providers.keys(),
+                filter,
+              });
+              for (const [id, on] of decoded.providers) providers.set(id, on);
+              return true;
+            },
+          }
+        : fakeLayer(id),
+    );
+  }
+  manager.finalizeRegistrations(LAYER_STATE_REGISTRY);
+  const storage = memoryStorage();
+  const coordinator = new LayerStateCoordinator(manager, shareSink(), {
+    storage,
+  });
+  try {
+    providers.set('beta', false); // Passive state does not belong to the next action.
+    assert.equal(
+      manager.setLayerParams(
+        'street-level',
+        { alpha: false },
+        { origin: 'user' },
+      ),
+      true,
+    );
+    let saved = parseStoredLayerState(storage.getItem(LAYER_STATE_STORAGE_KEY));
+    assert.equal(saved.options['street-level'].providerSwitches, 'alpha-0');
+    const shared = decodeLayerStateParams(new URLSearchParams(encode(saved)));
+    const restored = decodeParams(shared.options['street-level'], {
+      providerIds: ['beta', 'alpha'],
+      filter,
+    });
+    assert.deepEqual([...restored.providers], [['alpha', false]]);
+    manager.setLayerParams('street-level', { beta: true }, { origin: 'user' });
+    saved = parseStoredLayerState(storage.getItem(LAYER_STATE_STORAGE_KEY));
+    assert.equal(
+      saved.options['street-level'].providerSwitches,
+      'alpha-0*beta-1',
+    );
+    manager.setLayerParams(
+      'street-level',
+      { alpha: true },
+      { origin: 'local-restore' },
+    );
+    saved = parseStoredLayerState(storage.getItem(LAYER_STATE_STORAGE_KEY));
+    assert.equal(
+      saved.options['street-level'].providerSwitches,
+      'alpha-0*beta-1',
+    );
+  } finally {
+    coordinator.destroy();
+  }
+});

src/data/layerStateCoordinator.js

@@ -255,8 +255,22 @@ export class LayerStateCoordinator {
       const explicitlyRequested = Object.hasOwn(requestedParams, spec.key);
       const implicitTrackingSync =
         !explicitlyRequested && spec.key === trackingOptionKey;
-      if (!explicitlyRequested && !implicitTrackingSync) continue;
-      const value = spec.normalize(change.params[spec.key]);
+      // Packed options can persist only the subkeys owned by this request.
+      const requestedValue =
+        explicitlyRequested || implicitTrackingSync
+          ? change.params[spec.key]
+          : spec.patchRequested?.(
+              nextOwnerOptions[spec.key],
+              change.params[spec.key],
+              requestedParams,
+            );
+      if (
+        !explicitlyRequested &&
+        !implicitTrackingSync &&
+        requestedValue === undefined
+      )
+        continue;
+      const value = spec.normalize(requestedValue);
       if (value === null) {
         if (implicitTrackingSync) {
           nextOwnerOptions[spec.key] = null;

src/layers/streetLevel/providerSwitches.test.mjs

@@ -3,6 +3,7 @@ import assert from 'node:assert/strict';
 import { encodeParams, decodeParams } from './params.js';
 import {
   normalizeIdSwitches,
+  patchRequestedIdSwitches,
   decodeIdSwitches,
   encodeIdSwitches,
 } from '../../data/idSwitches.js';
@@ -137,3 +138,16 @@ test('neutral switch codec preserves hyphens and numeric suffixes in IDs', () =>
   for (const [id, on] of switches) assert.equal(decoded.get(id), on);
   assert.equal(decodeIdSwitches('valid-1*broken').size, 0);
 });
+
+test('editing a receiving composition drops unknown IDs before enforcing the share bound', () => {
+  const previous = `${'x'.repeat(254)}-1`;
+  assert.equal(normalizeIdSwitches(previous), previous);
+  assert.equal(
+    patchRequestedIdSwitches(previous, 'alpha-0*beta-0', { alpha: false }),
+    'alpha-0',
+  );
+  assert.equal(
+    patchRequestedIdSwitches(previous, 'alpha-0', { pano: 'flat' }),
+    undefined,
+  );
+});