Properly handle undefined value for input subscribe callback (#4243)

* Close #4240: properly handle undefined value for input subscribe callback

* Refactor normalization into a function

inst/www/shared/shiny.js

@@ -5619,9 +5619,22 @@
       const type = binding.getType(el);
       if (type)
         id = id + ":" + type;
-      inputs.setInput(id, value, { priority, binding, el });
+      const normalizedPriority = normalizeEventPriority(priority);
+      inputs.setInput(id, value, { priority: normalizedPriority, binding, el });
     }
   }
+  function normalizeEventPriority(priority) {
+    if (priority === false || priority === void 0) {
+      return "immediate";
+    }
+    if (priority === true) {
+      return "deferred";
+    }
+    if (typeof priority === "object" && "priority" in priority) {
+      return priority.priority;
+    }
+    return priority;
+  }
   var bindingsRegistry = (() => {
     const bindings = /* @__PURE__ */ new Map();
     function checkValidity(scope) {
@@ -5735,17 +5748,7 @@ ${duplicateIdMsg}`;
           const thisBinding = binding;
           const thisEl = el;
           return function(priority) {
-            let normalizedPriority;
-            if (priority === true) {
-              normalizedPriority = "deferred";
-            } else if (priority === false) {
-              normalizedPriority = "immediate";
-            } else if (typeof priority === "object" && "priority" in priority) {
-              normalizedPriority = priority.priority;
-            } else {
-              normalizedPriority = priority;
-            }
-            valueChangeCallback(inputs, thisBinding, thisEl, normalizedPriority);
+            valueChangeCallback(inputs, thisBinding, thisEl, priority);
           };
         }();
         binding.subscribe(el, thisCallback);

srcts/src/shiny/bind.ts

@@ -29,7 +29,7 @@ function valueChangeCallback(
   inputs: InputValidateDecorator,
   binding: InputBinding,
   el: HTMLElement,
-  priority: EventPriority
+  priority?: SubscribeEventPriority
 ) {
   let id = binding.getId(el);
 
@@ -39,10 +39,32 @@ function valueChangeCallback(
 
     if (type) id = id + ":" + type;
 
-    inputs.setInput(id, value, { priority, binding, el });
+    // Normalize the priority to a valid EventPriority
+    const normalizedPriority = normalizeEventPriority(priority);
+
+    inputs.setInput(id, value, { priority: normalizedPriority, binding, el });
   }
 }
 
+// Narrow the type of the subscribe callback value to EventPriority
+function normalizeEventPriority(
+  priority?: SubscribeEventPriority
+): EventPriority {
+  if (priority === false || priority === undefined) {
+    return "immediate";
+  }
+
+  if (priority === true) {
+    return "deferred";
+  }
+
+  if (typeof priority === "object" && "priority" in priority) {
+    return priority.priority;
+  }
+
+  return priority;
+}
+
 /**
  * Registry for input and output binding IDs. Used to check for duplicate IDs
  * and to keep track of which IDs have already been added to the app. Use an
@@ -264,20 +286,8 @@ function bindInputs(
         const thisBinding = binding;
         const thisEl = el;
 
-        return function (priority: SubscribeEventPriority) {
-          // Narrow the type of priority to EventPriority
-          let normalizedPriority: EventPriority;
-          if (priority === true) {
-            normalizedPriority = "deferred";
-          } else if (priority === false) {
-            normalizedPriority = "immediate";
-          } else if (typeof priority === "object" && "priority" in priority) {
-            normalizedPriority = priority.priority;
-          } else {
-            normalizedPriority = priority;
-          }
-
-          valueChangeCallback(inputs, thisBinding, thisEl, normalizedPriority);
+        return function (priority?: SubscribeEventPriority) {
+          valueChangeCallback(inputs, thisBinding, thisEl, priority);
         };
       })();