Merge pull request #5 from vinniegarcia/multi-return

Support multiple return values via array, fixes #4

.travis.yml

@@ -1,8 +1,8 @@
 language: node_js
 node_js:
   - "0.12"
-  - "0.11"
   - "0.10"
   - "iojs-v1.4.2"
+  - "iojs-v2.3.3"
 install: npm i
 script: npm test

README.md

@@ -3,7 +3,7 @@
 [![travis build information](https://api.travis-ci.org/vinniegarcia/proposal.svg)](https://travis-ci.org/vinniegarcia/proposal)
 [![Coverage Status](https://coveralls.io/repos/vinniegarcia/proposal/badge.svg)](https://coveralls.io/r/vinniegarcia/proposal)
 
-Callback to Promise converter. A `Proposal` is a bridge function between node-style asynchronous functions with callbacks in the form of `(err, data) => void` (which from here on out I'll refer to as `nodebacks`) and ECMAScript 6 `Promises`.
+Callback to Promise converter. A `Proposal` is a bridge function between node-style asynchronous functions with callbacks in the form of `(err, data) => void` or `(err, [data]) => void` (which from here on out I'll refer to as `nodebacks`) and ECMAScript 6 `Promises`.
 
 ## Installation
 Required: [nodejs](http://nodejs.org/) (tested against v0.10 and 0.12), or [io.js](https://iojs.org/) (tested against v1.4.2), [npm](https://www.npmjs.com/).
@@ -96,6 +96,11 @@ var fs = require('fs'),
   var buffy = Proposal(crypto.randomBytes, 512);
   console.log(buffy instanceof Promise); // => true, is not a value
   ```
-3. _I have another question that's not listed here._
+3. _My nodeback has several data return values, like [`child_process.exec`](https://nodejs.org/api/child_process.html#child_process_child_process_exec_command_options_callback), which, on success, returns an `stdout` and an `stderr` Buffer. Is this supported?_
+
+  Yes, in this case `resolve` will return an `Array` with the data return values. While ugly-ish,
+  it does work well in practice, as multiple arguments are [not allowed](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/then) in `onFulfilled`.
+
+4. _I have another question that's not listed here._
 
     Raise an issue and I'll get to it as soon as I can. Thanks for reading this far!

package.json

@@ -1,15 +1,15 @@
 {
   "name": "proposal",
-  "version": "1.1.1",
+  "version": "1.2.0",
   "description": "Takes a node-style callbacking function and converts it into a Promise automagically",
   "main": "dist/index.js",
   "scripts": {
     "lint": "eslint src/**/*.es6",
-    "compile": "babel --experimental -d dist/ src/",
+    "compile": "babel --stage 0 -d dist/ src/",
     "copydata": "mkdir -p dist/test/fixtures && cp -R src/test/fixtures/* dist/test/fixtures/",
     "cc": "npm run compile && npm run copydata",
     "prepublish": "npm run cc",
-    "mocha": "npm run cc && ./node_modules/mocha/bin/_mocha dist/test/*.js",
+    "mocha": "npm run cc && ./node_modules/mocha/bin/_mocha dist/test/*.js --timeout 10000",
     "istanbul": "npm run cc && istanbul cover ./node_modules/mocha/bin/_mocha --report lcovonly dist/test/*.js",
     "coverage": "npm run cc && istanbul cover ./node_modules/mocha/bin/_mocha --report html dist/test/*.js",
     "coveralls": "cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js && rm -rf ./coverage",
@@ -32,12 +32,13 @@
   "homepage": "https://github.com/vinniegarcia/proposal",
   "devDependencies": {
     "coveralls": "^2.11.2",
-    "istanbul": "^0.3.7",
-    "mocha": "^2.1.0",
+    "httpreq": "^0.4.12",
+    "istanbul": "^0.3.17",
+    "mocha": "^2.2.5",
     "mocha-lcov-reporter": "0.0.2",
     "node-emoji": "^0.1.0"
   },
   "dependencies": {
-    "babel": "^4.6.3"
+    "babel": "^5.6.14"
   }
 }

src/.eslintrc

@@ -0,0 +1,16 @@
+{
+
+  "parser": "babel-eslint",
+  "env": {
+    "browser": false,
+    "es6": true,
+    "node": true
+  },
+
+  "rules": {
+    "quotes": [2, "single"],
+    "eol-last": [0],
+    "no-mixed-requires": [0],
+    "no-underscore-dangle": [0]
+  }
+}

src/index.es6

@@ -2,18 +2,20 @@
 
 import 'babel/polyfill';
 
-//convert the err,data callback to promise resolve/reject calls
-const denode = (resolve, reject) => (err, data) => (err) ? reject(err) : resolve(data);
+// Converts the (err, data) or (err, [data]) callback to Promise resolve/reject calls.
+// Resolves with either the data or the [data] fulfillment argument, as onFulfilled
+// takes exactly one argument (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/then).
+const denode = (resolve, reject) => (err, ...args) => (err) ? reject(err) : resolve((args.length > 1) ? args : args[0]);
 
-//take a node-style function that sends an (err, result)
-//callback and turns it into a promise
+// Takes a node-style function that sends an (err, result) or (err, [result])
+// callback and turns it into a Promise.
 const promiseMe = (f, ...args) => new Promise((resolve, reject) => f(...args, denode(resolve, reject)));
 
-//waits for parameters before creating the Promise
+// Waits for parameters before creating the Promise.
 const curryWrap = (f) => (...more) => promiseMe(f, ...more);
 
-// if args given, return a promise for the operation.
-// if not, return a new function that waits for more input.
+// If args are given, returns a Promise for the operation.
+// Else, returns a new function that waits for more input.
 const Proposal = (nodefn, ...args) => (args.length > 0) ? promiseMe(nodefn, ...args) : curryWrap(nodefn);
 
 export default Proposal;

src/test/.eslintrc

@@ -0,0 +1,18 @@
+{
+
+  "parser": "babel-eslint",
+  "env": {
+    "browser": false,
+    "es6": true,
+    "node": true,
+    "mocha": true
+  },
+
+  "rules": {
+    "quotes": [2, "single"],
+    "new-cap": false,
+    "eol-last": [0],
+    "no-mixed-requires": [0],
+    "no-underscore-dangle": [0]
+  }
+}

src/test/multi-return.es6

@@ -0,0 +1,54 @@
+'use strict';
+
+import {ok} from 'assert';
+import http from 'http';
+import req from 'httpreq';
+import {exec} from 'child_process';
+import { h1, cool, fw } from './fixtures/emoji';
+import Proposal from '../index';
+
+describe(h1('multiple return values test'), () => {
+  const handler = (req, res) => {
+      res.writeHead(200);
+      res.end(fw('TEST RESULT\n'));
+    },
+      serv = http.createServer(handler);
+    serv.on('listening', () => {
+       console.log(fw('server listening'));
+    });
+
+  before((done) => {
+    serv.listen(8912);
+    done();
+  });
+
+  after((done) => {
+    serv.close(done);
+  });
+
+  it(cool('returns one value, the response of a http get call'), (done) => {
+    const getIt = Proposal(req.get);
+
+    getIt('http://localhost:8912/').then((response) => {
+      ok(!Array.isArray(response));
+      done();
+    })
+    .catch(done);
+  });
+
+  it(cool('returns multiple values, the stdout and stderr from an executed child process'),
+    async function (done) {
+      this.timeout(10000);
+
+      const futureExec = Proposal(exec);
+      try {
+        const [stout, sterr] = await futureExec('curl -# http://127.0.0.1:8912/', {});
+        ok(typeof stout === 'string' && typeof sterr === 'string');
+        done();
+      } catch (err) {
+        done(err);
+      }
+    }
+  );
+
+});