Fix UMD builds by re-exporting the scheduler priorities

packages/react/src/ReactSharedInternals.js

@@ -18,6 +18,11 @@ import {
   unstable_continueExecution,
   unstable_wrapCallback,
   unstable_getCurrentPriorityLevel,
+  unstable_IdlePriority,
+  unstable_ImmediatePriority,
+  unstable_LowPriority,
+  unstable_NormalPriority,
+  unstable_UserBlockingPriority,
 } from 'scheduler';
 import {
   __interactionsRef,
@@ -60,6 +65,11 @@ if (__UMD__) {
       unstable_pauseExecution,
       unstable_continueExecution,
       unstable_getCurrentPriorityLevel,
+      unstable_IdlePriority,
+      unstable_ImmediatePriority,
+      unstable_LowPriority,
+      unstable_NormalPriority,
+      unstable_UserBlockingPriority,
     },
     SchedulerTracing: {
       __interactionsRef,

packages/scheduler/npm/umd/scheduler.development.js

@@ -108,5 +108,25 @@
     unstable_continueExecution: unstable_continueExecution,
     unstable_pauseExecution: unstable_pauseExecution,
     unstable_getFirstCallbackNode: unstable_getFirstCallbackNode,
+    get unstable_IdlePriority() {
+      return global.React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+        .Scheduler.unstable_IdlePriority;
+    },
+    get unstable_ImmediatePriority() {
+      return global.React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+        .Scheduler.unstable_ImmediatePriority;
+    },
+    get unstable_LowPriority() {
+      return global.React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+        .Scheduler.unstable_LowPriority;
+    },
+    get unstable_NormalPriority() {
+      return global.React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+        .Scheduler.unstable_NormalPriority;
+    },
+    get unstable_UserBlockingPriority() {
+      return global.React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+        .Scheduler.unstable_UserBlockingPriority;
+    },
   });
 });

packages/scheduler/npm/umd/scheduler.production.min.js

@@ -102,5 +102,25 @@
     unstable_continueExecution: unstable_continueExecution,
     unstable_pauseExecution: unstable_pauseExecution,
     unstable_getFirstCallbackNode: unstable_getFirstCallbackNode,
+    get unstable_IdlePriority() {
+      return global.React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+        .Scheduler.unstable_IdlePriority;
+    },
+    get unstable_ImmediatePriority() {
+      return global.React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+        .Scheduler.unstable_ImmediatePriority;
+    },
+    get unstable_LowPriority() {
+      return global.React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+        .Scheduler.unstable_LowPriority;
+    },
+    get unstable_NormalPriority() {
+      return global.React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+        .Scheduler.unstable_NormalPriority;
+    },
+    get unstable_UserBlockingPriority() {
+      return global.React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+        .Scheduler.unstable_UserBlockingPriority;
+    },
   });
 });

packages/scheduler/npm/umd/scheduler.profiling.min.js

@@ -102,5 +102,25 @@
     unstable_continueExecution: unstable_continueExecution,
     unstable_pauseExecution: unstable_pauseExecution,
     unstable_getFirstCallbackNode: unstable_getFirstCallbackNode,
+    get unstable_IdlePriority() {
+      return global.React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+        .Scheduler.unstable_IdlePriority;
+    },
+    get unstable_ImmediatePriority() {
+      return global.React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+        .Scheduler.unstable_ImmediatePriority;
+    },
+    get unstable_LowPriority() {
+      return global.React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+        .Scheduler.unstable_LowPriority;
+    },
+    get unstable_NormalPriority() {
+      return global.React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+        .Scheduler.unstable_NormalPriority;
+    },
+    get unstable_UserBlockingPriority() {
+      return global.React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+        .Scheduler.unstable_UserBlockingPriority;
+    },
   });
 });

packages/scheduler/src/__tests__/SchedulerUMDBundle-test.internal.js

@@ -17,8 +17,17 @@ describe('Scheduling UMD bundle', () => {
   });
 
   function filterPrivateKeys(name) {
-    // TODO: Figure out how to forward priority levels.
-    return !name.startsWith('_') && !name.endsWith('Priority');
+    // Be very careful adding things to this whitelist!
+    // It's easy to introduce bugs by doing it:
+    // https://github.com/facebook/react/issues/14904
+    switch (name) {
+      case '__interactionsRef':
+      case '__subscriberRef':
+        // Don't forward these. (TODO: why?)
+        return false;
+      default:
+        return true;
+    }
   }
 
   function validateForwardedAPIs(api, forwardedAPIs) {