caco - npm Package Compare versions

Comparing version 0.0.1 to 1.0.0

index.js

@@ -0,1 +1,8 @@
+var isGenerator = function (val) {
+  return val && typeof val.next === 'function' && typeof val.throw === 'function'
+}
+var isPromise = function (val) {
+  return val && typeof val.then === 'function'
+}
+
 module.exports = function caco (gen) {
@@ -8,9 +15,5 @@ return function () {
 
-    args.push(function next (err, res) {
-      process.nextTick(function () {
-        step(err, res)
-      })
-    })
+    args.push(next)
 
-    var iter = gen.apply(self, args)
+    var iter = isGenerator(gen) ? gen : gen.apply(self, args)
 
@@ -24,3 +27,3 @@ function step (err, res) {
 
-        if (state.value && typeof state.value.then === 'function') {
+        if (isPromise(state.value)) {
           // handle thenable
@@ -32,2 +35,4 @@ state.value.then(function (value) {
           })
+        } else if (isGenerator(state.value)) {
+          caco(state.value)(next)
         } else if (state.done) {
@@ -42,2 +47,8 @@ step(null, state.value)
 
+    function next (err, res) {
+      process.nextTick(function () {
+        step(err, res)
+      })
+    }
+
     if (callback) {
@@ -44,0 +55,0 @@ step()

package.json

 {
   "name": "caco",
-  "version": "0.0.1",
-  "description": "Async generator control flow that supports both callback and promise",
+  "version": "1.0.0",
+  "description": "Generator based control flow that supports both callbacks and promises",
   "scripts": {
@@ -6,0 +6,0 @@ "test": "standard && node test.js"

README.md

@@ -1,33 +0,39 @@
-# sema
+# caco
 
-Async semaphore for shared or exclusive execution of JavaScript functions.
+Generator based control flow that supports both callbacks and promises.
 
-[![Build Status](https://travis-ci.org/cshum/sema.svg?branch=master)](https://travis-ci.org/cshum/sema)
+[![Build Status](https://travis-ci.org/cshum/caco.svg?branch=master)](https://travis-ci.org/cshum/caco)
 
+Many of the existing async libraries require wrapping callback functions into promises to be usuable, which creates unnecessary complication. 
+
+In caco, both callbacks and promises are 'yieldable'; 
+resulting function can be used by both callbacks and promises. 
+This enables a powerful control flow while maintaining compatibility.
+
+```bash
+npm install caco
 ```
-npm install sema
-```
 
 ```js
-var sema = require('sema')
-var s = sema()
+var caco = require('caco')
 
-// exclusive mode
-s.acquire(function () {
-  ...
-  doReadWrite(function (err) {
-    ...
-    s.release()
-  })
-})
+var fn = caco(function * (next) {
+  var foo = yield Promise.resolve('bar') // yield promise
+  yield setTimeout(next, 100) // yield callback using 'next' argument
 
-// shared mode
-s.acquire(sema.SHARED, function () {
-  ...
-  doReadOnly(function (err) {
-    ...
-    s.release()
-  })
+  // try/catch errors
+  try {
+    yield Promise.reject('boom')
+  } catch (err) {
+    console.log(err) // 'boom'
+  }
+
+  var data = yield fs.readFile('./foo/bar', next)
+  return data
 })
 
+// consume with callback
+fn(function (err, res) { })
+
+fn().then(...).catch(...)
 ```
@@ -37,30 +43,26 @@
 
-### var s = sema()
-Creates a semaphore instance.
+#### var fn = caco(fn *)
 
-### s.acquire([mode], [fn])
-Acquire semaphore. Defaults to exclusive mode. Setting mode `sema.SHARED` to acquire a shared mode.
+Wraps a generator into a regular function that acceots callback or promise.
 
-Callback to asynchronous function `fn` when semaphore available. 
-Invoked immediately if semaphore is free or shared only. Otherwise pushed to the wait queue.
+```js
+var getN = caco(function * (n, next) {
+  if (n === 689) yield Promise.reject('boom') // yield reject throws error
+  return yield Promise.resolve(n)
+})
 
-Returns a promise if no `fn` provided. However this yields a slight delay when acquiring, due to the nature of promise. If such timing is important then callback function should be used.
+getN(123, function (err, val) {
+  console.log(val) // 123
+})
+getN(123).then(...)
 
-### s.release()
-Release semaphore.
+getN(689).catch(function (err) {
+  console.log(err) // boom
+})
+```
 
-Invokes function from the wait queue if queue is not empty.
+Generator accepts optional `next` argument for yieldable callback
 
-### s.mode()
+## License
 
-Returns mode constant, the current state of semaphore.
-
-### Mode Constants
-
-* **`sema.FREE = null`** 
-* **`sema.SHARED = 1`** 
-* **`sema.EXCLUSIVE = 2`** 
-* **`sema.WAIT = 3`** 
-
-## License
 MIT

test.js

@@ -5,5 +5,9 @@ var test = require('tape')
 test('caco', function (t) {
-  t.plan(3)
-  var v = caco(function * () {
-    return 167
+  t.plan(5)
+
+  function * v (n) {
+    return yield Promise.resolve(n)
+  }
+  var n = caco(function * (n) {
+    return yield Promise.reject(n)
   })
@@ -15,3 +19,7 @@ var v1 = caco(function * (next) {
   var v2 = caco(function * () {
-    return yield v()
+    try {
+      return yield n(689)
+    } catch (e) {
+      return yield v(167)
+    }
   })
@@ -23,2 +31,10 @@ var f = caco(function * (str, next) {
 
+  n('boom', function (err) {
+    t.equal(err, 'boom', 'correct callback error')
+  })
+
+  n('boom').then(t.error).catch(function (err) {
+    t.equal(err, 'boom', 'correct promise reject')
+  })
+
   f('D7', function (err, res) {
@@ -25,0 +41,0 @@ t.notOk(err, 'no error')

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Improved metrics

Total package byte prevSize

5764

increased by16.26%

Lines of code

95

increased by30.14%

Number of low quality alerts

1

decreased by-50%

Number of lines in readme file

68

increased by3.03%

No dependency changes