Improve runPromise

README.md

@@ -8,7 +8,7 @@
 
 ### When running Nodejs version < 8, this module uses [AsyncWrap](https://github.com/nodejs/node-eps/blob/async-wrap-ep/XXX-asyncwrap-api.md) which is an unsupported Nodejs API, so please consider the risk before using it.
 
-### When running Nodejs version >= 8.2.1, this module uses the newer [async_hooks](https://github.com/nodejs/node/blob/master/doc/api/async_hooks.md) API which is considered `Experimental` by Nodejs. 
+### When running Nodejs version >= 8.2.1, this module uses the newer [async_hooks](https://github.com/nodejs/node/blob/master/doc/api/async_hooks.md) API which is considered `Experimental` by Nodejs.
 
 ### Thanks to [@trevnorris](https://github.com/trevnorris) for [AsyncWrap](https://github.com/nodejs/node-eps/blob/async-wrap-ep/XXX-asyncwrap-api.md), [async_hooks](https://github.com/nodejs/node/blob/master/doc/api/async_hooks.md) and all the async work in Node and [@AndreasMadsen](https://github.com/AndreasMadsen) for [async-hook](https://github.com/AndreasMadsen/async-hook)
 
@@ -18,7 +18,7 @@
 2. Second implementation called **[AsyncWrap, async-wrap or async_wrap](https://github.com/nodejs/node-eps/blob/async-wrap-ep/XXX-asyncwrap-api.md)** was included to Nodejs v0.12.
     - `AsyncWrap` is unofficial and undocumented but is currently in Nodejs versions 6 & 7
     - `cls-hooked` uses `AsyncWrap` when run in Node < 8.
-3. Third implementation and [offically Node-eps accepted](https://github.com/nodejs/node-eps/blob/master/006-asynchooks-api.md) **AsyncHooks ([async_hooks](https://github.com/nodejs/node/blob/master/doc/api/async_hooks.md)) API** was included in Nodejs v8. :) 
+3. Third implementation and [offically Node-eps accepted](https://github.com/nodejs/node-eps/blob/master/006-asynchooks-api.md) **AsyncHooks ([async_hooks](https://github.com/nodejs/node/blob/master/doc/api/async_hooks.md)) API** was included in Nodejs v8. :)
 **The latest version of `cls-hooked` uses [async_hooks](https://github.com/nodejs/node/blob/master/doc/api/async_hooks.md) API when run in Node >= 8.2.1**
 
 ---
@@ -219,6 +219,20 @@ when it's called.
 Same as `namespace.run()` but returns the return value of the callback rather
 than the context.
 
+### namespace.runPromise(callback)
+
+* return: the return value of the callback
+
+Create a new context on which values can be set or read. Run all the functions
+that are called (either directly, or indirectly through asynchronous functions
+that take callbacks themselves) from the provided callback within the scope of
+that namespace. The new context is passed as an argument to the callback
+when it's called.
+
+Similar to `namespace.run()` but the callback may return a promise. The
+function returns a promise which resolves or rejects to the value or reason
+of the promise returned by the callback.
+
 ### namespace.bind(callback, [context])
 
 * return: a callback wrapped up in a context closure

context-legacy.js

@@ -126,17 +126,12 @@ Namespace.prototype.runPromise = function runPromise(fn) {
   let context = this.createContext();
   this.enter(context);
 
-  let promise = fn(context);
-  if (!promise || !promise.then || !promise.catch) {
-    throw new Error('fn must return a promise.');
-  }
-
   if (DEBUG_CLS_HOOKED) {
     debug2(' BEFORE runPromise: ' + this.name + ' uid:' + currentUid + ' len:' + this._set.length + ' ' +
       util.inspect(context));
   }
 
-  return promise
+  return new Promise((resolve) => { resolve(fn(context)); })
     .then(result => {
       if (DEBUG_CLS_HOOKED) {
         debug2(' AFTER runPromise: ' + this.name + ' uid:' + currentUid + ' len:' + this._set.length + ' ' +

context.js

@@ -129,16 +129,11 @@ Namespace.prototype.runPromise = function runPromise(fn) {
   let context = this.createContext();
   this.enter(context);
 
-  let promise = fn(context);
-  if (!promise || !promise.then || !promise.catch) {
-    throw new Error('fn must return a promise.');
-  }
-
   if (DEBUG_CLS_HOOKED) {
     debug2('CONTEXT-runPromise BEFORE: (' + this.name + ') currentUid:' + currentUid + ' len:' + this._set.length + ' ' + util.inspect(context));
   }
 
-  return promise
+  return new Promise((resolve) => { resolve(fn(context)); })
     .then(result => {
       if (DEBUG_CLS_HOOKED) {
         debug2('CONTEXT-runPromise AFTER then: (' + this.name + ') currentUid:' + currentUid + ' len:' + this._set.length + ' ' + util.inspect(context));