renamed options

Author: Eetay Natan

README.md

@@ -26,8 +26,8 @@ function nextPromise({index, data}) {
 
 var all = promisePool({
   threads: 3,                 // maximum parallel promises
-  next_promise: nextPromise,  // function to get/generate next promise
-  next_promise_data: 17       // user data for the next_promise function
+  promises: nextPromise,  // function to get/generate next promise
+  context_data: 17       // user data for the next_promise function
 })
 
 all.then(function(result) {
@@ -78,34 +78,49 @@ const promiseList = [
 
 promisePool({
   threads: 3,
-  next_promise: promiseList,              // List of promises
-  next_promise_data: 'data for context'
+  promises: promiseList,              // List of promises
+  context_data: 'data for context'
 }).then(function(result) {
   ...
 })
 ```
 
+## Using generator to generate promises:
+
+```javascript
+function *createPromiseMaker() {
+  for (var i=0; i<10; i+=1) {
+    yield new Promise(...)
+  }
+}
+
+const pool = promisePool({
+  threads: 3,
+  promises: createPromiseMaker()
+})
+```
+
 ## Nested promise pools:
 
 ```javascript
 const innerPool = promisePool({
   threads: 2,
-  next_promise: [
+  promises: [
     makePromise(2),
     makePromise(3),
     makePromise(4),
     makePromise(5)
   ],
-  next_promise_data: 'secondary promise pool'
+  context_data: 'secondary promise pool'
 })
 const pool = promisePool({
   threads: 3,
-  next_promise: [
+  promises: [
     makePromise(0),
     makePromise(1),
     innerPool
   ],
-  next_promise_data: 'primary promise pool'
+  context_data: 'primary promise pool'
 })
 pool.then(function(result) {
   ...
@@ -119,3 +134,11 @@ pool.then(function(result) {
   - wait for all to resolve even if some are rejected (same as Promise.when)
 - support listeners for individual promise completions/rejections
 
+## migration from previous versions:
+the following option keys are renamed:
+1. next_promise_data -> context_data
+2. next_promise -> promises
+2. max_parallel -> threads
+
+you can still use the older option keys, but they are deprecated
+

promise-pool.js

@@ -1,11 +1,11 @@
-function promisePool({max_parallel, next_promise, next_promise_data, threads, promises, user_data}) {
+function promisePool({max_parallel, next_promise, next_promise_data, threads, promises, context_data}) {
   var promises_generator = promises || next_promise
   var self = {
     threads: max_parallel || threads,
     started: 0,
     ended: 0,
     promises_generator: Array.isArray(promises_generator) ? [...promises_generator] : promises_generator,
-    next_promise_data: next_promise_data || user_data,
+    next_promise_data: next_promise_data || context_data,
     results: []
   }
   self.live = self.threads
@@ -17,7 +17,7 @@ function promisePool({max_parallel, next_promise, next_promise_data, threads, pr
         data: self.next_promise_data,
         ended: false
       }
-      const next = Array.isArray(self.promises_generator) ? self.promises_generator.shift() : self.promises_generator({ index: self.started, data: self.next_promise_data })
+      const next = promises_generator.next ? promises_generator.next().value : (Array.isArray(self.promises_generator) ? self.promises_generator.shift() : self.promises_generator({ index: self.started, data: self.next_promise_data }))
       self.started += 1
       if (next && next.then) {
         //console.log('promise ' + JSON.stringify(context))

spec/promise-pool.spec.js

@@ -54,11 +54,31 @@ test('Nested promise pools', (done) => {
   })
 })
 
-test('Array of promises', (done) => {
-  expect.assertions(1)
+test('Generator functions', (done) => {
+  expect.assertions(2)
+  var total = 10
+  function *createPromiseMaker() {
+    for (var i=0; i<total; i+=1) {
+      yield makePromise(i, randomTimeout())
+    }
+  }
+  const pool = promisePool({
+    threads: 3,
+    promises: createPromiseMaker()
+  })
+  pool.then(function(result) {
+    expect(result.length).toBe(total)
+    expect(result[2].result).toEqual(2)
+    done()
+  })
+})
+
+
+test('Array of promises & order of execution', (done) => {
+  expect.assertions(3)
   const promiseList = [
-    makePromise(0),
-    makePromise(1)
+    makePromise(0,20),
+    makePromise(1,10)
   ]
   const pool = promisePool({
     threads: 3,
@@ -67,6 +87,8 @@ test('Array of promises', (done) => {
   })
   pool.then(function(result) {
     expect(result.length).toBe(promiseList.length)
+    expect(result[1].result).toBe(1)
+    expect(result[1].context.ended).toBe(0) // first to finish
     done()
   })
 })