Clarify doWhilst/doUntil docs. Closes #1107

README.md

@@ -919,7 +919,7 @@ async.whilst(
 ### doWhilst(fn, test, callback)
 
 The post-check version of [`whilst`](#whilst). To reflect the difference in
-the order of operations, the arguments `test` and `fn` are switched.
+the order of operations, the arguments `test` and `fn` are switched. The `test` function is also passed the non-error callback results of `fn`.
 
 `doWhilst` is to `whilst` as `do while` is to `while` in plain JavaScript.
 
@@ -941,7 +941,7 @@ The inverse of [`whilst`](#whilst).
 
 ### doUntil(fn, test, callback)
 
-Like [`doWhilst`](#doWhilst), except the `test` is inverted. Note the argument ordering differs from `until`.
+Like [`doWhilst`](#doWhilst), except the `test` is inverted. Note the argument ordering differs from `until`. The `test` function is also passed the non-error callback results of `fn`.
 
 ---------------------------------------
 

lib/doUntil.js

@@ -14,8 +14,8 @@ import doWhilst from './doWhilst';
  * @param {Function} fn - A function which is called each time `test` fails.
  * The function is passed a `callback(err)`, which must be called once it has
  * completed with an optional `err` argument. Invoked with (callback).
- * @param {Function} test - synchronous truth test to perform before each
- * execution of `fn`. Invoked with ().
+ * @param {Function} test - synchronous truth test to perform after each
+ * execution of `fn`. Invoked with the non-error callback results of `fn`.
  * @param {Function} [callback] - A callback which is called after the test
  * function has passed and repeated execution of `fn` has stopped. `callback`
  * will be passed an error and any arguments passed to the final `fn`'s

lib/doWhilst.js

@@ -16,8 +16,9 @@ import whilst from './whilst';
  * @param {Function} fn - A function which is called each time `test` passes.
  * The function is passed a `callback(err)`, which must be called once it has
  * completed with an optional `err` argument. Invoked with (callback).
- * @param {Function} test - synchronous truth test to perform before each
- * execution of `fn`. Invoked with ().
+ * @param {Function} test - synchronous truth test to perform after each
+ * execution of `fn`. Invoked with Invoked with the non-error callback results
+ * of `fn`.
  * @param {Function} [callback] - A callback which is called after the test
  * function has failed and repeated execution of `fn` has stopped. `callback`
  * will be passed an error and any arguments passed to the final `fn`'s