domain: consolidate run/bound/intercepted into runInDomain

Extract common domain context setup/teardown logic into a single
runInDomain helper function, reducing code duplication.

Author: mcollina

lib/domain.js

@@ -459,26 +459,25 @@ Domain.prototype.remove = function(ee) {
 };
 
 
-Domain.prototype.run = function(fn) {
+// Helper to run a function within a domain context.
+// Uses enterWith instead of ALS.run() so the context is NOT automatically
+// restored on exception - this matches original domain behavior where
+// exit() only runs on success.
+function runInDomain(domain, thisArg, fn, args) {
   const currentStore = getDomainStore() || { domain: null, stack: [] };
   const newStack = ArrayPrototypeSlice(currentStore.stack);
-  ArrayPrototypePush(newStack, this);
-
-  const args = ArrayPrototypeSlice(arguments, 1);
+  ArrayPrototypePush(newStack, domain);
   const previousDomain = currentDomain;
   const previousStack = currentStack;
 
-  // Set currentDomain and currentStack before running so exception handler can see them
-  currentDomain = this;
+  currentDomain = domain;
   currentStack = newStack;
   updateExceptionCapture();
 
-  // Use enterWith instead of run() so the context is NOT automatically restored on exception.
-  // This matches the original domain.run() behavior where exit() only runs on success.
-  setDomainStore({ domain: this, stack: newStack });
-  exports.active = this;
+  setDomainStore({ domain, stack: newStack });
+  exports.active = domain;
 
-  const result = ReflectApply(fn, this, args);
+  const result = ReflectApply(fn, thisArg, args);
 
   // On success, restore context (if exception thrown, context stays for catch blocks)
   setDomainStore(currentStore);
@@ -488,6 +487,10 @@ Domain.prototype.run = function(fn) {
   updateExceptionCapture();
 
   return result;
+}
+
+Domain.prototype.run = function(fn) {
+  return runInDomain(this, this, fn, ArrayPrototypeSlice(arguments, 1));
 };
 
 
@@ -507,31 +510,7 @@ function intercepted(_this, self, cb, fnargs) {
     return;
   }
 
-  const currentStore = getDomainStore() || { domain: null, stack: [] };
-  const newStack = ArrayPrototypeSlice(currentStore.stack);
-  ArrayPrototypePush(newStack, self);
-  const args = ArrayPrototypeSlice(fnargs, 1);
-  const previousDomain = currentDomain;
-  const previousStack = currentStack;
-
-  currentDomain = self;
-  currentStack = newStack;
-  updateExceptionCapture();
-
-  // Use enterWith instead of run() so the context is NOT automatically restored on exception.
-  setDomainStore({ domain: self, stack: newStack });
-  exports.active = self;
-
-  const result = ReflectApply(cb, _this, args);
-
-  // On success, restore context
-  setDomainStore(currentStore);
-  exports.active = currentStore.domain;
-  currentDomain = previousDomain;
-  currentStack = previousStack;
-  updateExceptionCapture();
-
-  return result;
+  return runInDomain(self, _this, cb, ArrayPrototypeSlice(fnargs, 1));
 }
 
 
@@ -547,30 +526,7 @@ Domain.prototype.intercept = function(cb) {
 
 
 function bound(_this, self, cb, fnargs) {
-  const currentStore = getDomainStore() || { domain: null, stack: [] };
-  const newStack = ArrayPrototypeSlice(currentStore.stack);
-  ArrayPrototypePush(newStack, self);
-  const previousDomain = currentDomain;
-  const previousStack = currentStack;
-
-  currentDomain = self;
-  currentStack = newStack;
-  updateExceptionCapture();
-
-  // Use enterWith instead of run() so the context is NOT automatically restored on exception.
-  setDomainStore({ domain: self, stack: newStack });
-  exports.active = self;
-
-  const result = ReflectApply(cb, _this, fnargs);
-
-  // On success, restore context
-  setDomainStore(currentStore);
-  exports.active = currentStore.domain;
-  currentDomain = previousDomain;
-  currentStack = previousStack;
-  updateExceptionCapture();
-
-  return result;
+  return runInDomain(self, _this, cb, fnargs);
 }