Stop sharing a Data Library entry as on once its failed Remove switched it off

When Remove switched a layer off and then its destroy failed, the
manager published no visibility change, so the selection still listed
the entry as on: the link shared it as on and a reload restored it on
while its row read off. A failed Remove now drops the entry from what is
on and remembered whenever its layer ended up off.

src/library/controller.js

@@ -388,8 +388,19 @@ export function createDataLibrary({
       if (
         isRegistered(id) &&
         !(await dataManager.unregisterLibraryLayer(libraryLayerId(id)))
-      )
+      ) {
+        // Switched off before teardown failed: it is no longer on, so the
+        // link and what is remembered must not say it is.
+        if (!dataManager.isEnabled?.(libraryLayerId(id))) {
+          selection = {
+            ...selection,
+            on: selection.on.filter((other) => other !== id),
+          };
+          savedOn = savedOn.filter((other) => other !== id);
+          persist();
+        }
         return false;
+      }
       selection = {
         added: selection.added.filter((other) => other !== id),
         on: selection.on.filter((other) => other !== id),

src/library/controller.test.mjs

@@ -581,6 +581,41 @@ test('the URL keeps the opening lib= before availability loads and for entries i
   library.destroy();
 });
 
+test('a layer switched off before its teardown failed is no longer shared as on', async (t) => {
+  const manager = sealedManager(t);
+  const storage = memoryStorage();
+  const shareLink = shareLinkDouble();
+  const library = createDataLibrary({
+    entries,
+    ledger,
+    dataManager: manager,
+    services: {},
+    storage,
+    shareLink,
+    initialHash: '',
+    source: source({}),
+  });
+  await library.start();
+  await library.add('night-lights');
+  assert.equal(shareLink.encode(), '00');
+  const { module } = manager.layers.get('lib-night-lights');
+  const destroy = module.destroy;
+  module.destroy = async () => {
+    throw new Error('stuck');
+  };
+  t.mock.method(console, 'warn', () => {});
+  try {
+    assert.equal(await library.remove('night-lights'), false);
+    assert.equal(manager.isEnabled('lib-night-lights'), false);
+    assert.equal(shareLink.encode(), null);
+    const saved = JSON.parse(storage.store.get(LIBRARY_STORAGE_KEY));
+    assert.deepEqual(saved, { added: ['night-lights'], on: [] });
+  } finally {
+    module.destroy = destroy;
+  }
+  library.destroy();
+});
+
 test('zoom flies to an added layer through the caller, reset removes everything', async (t) => {
   const manager = sealedManager(t);
   const storage = memoryStorage();