fix(weather): preserve enable during first-load replacement

src/layers/weather/index.js

@@ -357,7 +357,7 @@ export function createWeatherLayer({
           signal: controller.signal,
         });
         if (!enabled || controller.signal.aborted || request !== controller)
-          return false;
+          return enabled && !signal?.aborted && request !== controller;
         if (snapshot.unavailable) {
           error = msg(
             'Weather source unavailable; previous observation retained',
@@ -376,7 +376,9 @@ export function createWeatherLayer({
           )
             await show(snapshot.latest, controller.signal);
           return (
-            !controller.signal.aborted && request === controller && enabled
+            enabled &&
+            !signal?.aborted &&
+            (!controller.signal.aborted || request !== controller)
           );
         }
         const time =
@@ -388,9 +390,14 @@ export function createWeatherLayer({
           (satellite && rendering.getDiagnostics().infrared !== infrared)
         )
           await show(time, controller.signal);
-        return !controller.signal.aborted && request === controller && enabled;
+        return (
+          enabled &&
+          !signal?.aborted &&
+          (!controller.signal.aborted || request !== controller)
+        );
       } catch (cause) {
-        if (controller.signal.aborted || request !== controller) return false;
+        if (controller.signal.aborted || request !== controller)
+          return enabled && !signal?.aborted && request !== controller;
         error = cause?.message || msg('Weather unavailable');
         stop();
         return true;

src/layers/weather/weather.test.mjs

@@ -694,7 +694,11 @@ test('superseding a pending stage preserves the newer manifest loading state', a
   await flush();
   const newer = h.layer.update();
   await flush();
-  assert.equal(await old, false);
+  assert.equal(
+    await old,
+    true,
+    'replacement is accepted by the enable lifecycle',
+  );
   assert.equal(
     h.layer.getStats().loading,
     true,
@@ -2311,3 +2315,29 @@ for (const product of ['radar', 'clouds-regional', 'lightning']) {
     assert.equal(h.viewer.camera.moveEnd.size, 0);
   });
 }
+
+test('a product replacement accepts supersession but never paints the obsolete first response', async () => {
+  const pending = [];
+  const h = layerHarness({
+    id: 'weather-satellite',
+    feed: {
+      getSnapshot: (args) => {
+        const task = deferred();
+        pending.push({ ...args, ...task });
+        return task.promise;
+      },
+    },
+  });
+  const first = h.layer.update();
+  h.layer.setParams({ product: 'clouds' });
+  assert.equal(pending.length, 2);
+  pending[0].resolve({ ...snapshot, product: 'clouds-regional' });
+  assert.equal(await first, true);
+  assert.equal(h.stages.length, 0);
+  pending[1].resolve({ ...snapshot, product: 'clouds' });
+  await flush();
+  h.stages.at(-1).finish();
+  await flush();
+  assert.equal(h.layer.getParams().product, 'clouds');
+  h.layer.destroy();
+});