Close #61 PR: Convert to promise API. Fixes #56

.jshintrc

@@ -9,5 +9,8 @@
 	"noarg": true,
 	"undef": true,
 	"unused": "vars",
-	"strict": true
+	"strict": true,
+	"predef": [
+		"-Promise"
+	]
 }

README.md

@@ -20,21 +20,23 @@ $ npm install --save psi
 var psi = require('psi');
 
 // get the PageSpeed Insights report
-psi('html5rocks.com', function (err, data) {
+psi('html5rocks.com').then(function (data) {
   console.log(data.ruleGroups.SPEED.score);
   console.log(data.pageStats);
 });
 
 // output a formatted report to the terminal
-psi.output('html5rocks.com', function (err) {
+psi.output('html5rocks.com').then(function () {
   console.log('done');
 });
 ```
 
 
 ## API
 
-### psi(url, [options], callback)
+### psi(url, [options])
+
+Returns a promise for the response data from Google PageSpeed Insights.
 
 #### url
 
@@ -76,26 +78,13 @@ Default: `70`
 
 Threshold score to pass the PageSpeed test.
 
-#### callback(error, data)
-
-*Required*  
-Type: `function`
-
-##### data
-
-Type: `object`
-
-The response from Google PageSpeed Insights.
-
-### psi.output(url, [options], [callback])
+### psi.output(url, [options])
 
 Output the formatted report to the terminal.
 
-`url` and `options` is the same as `psi()`.
+Returns a promise for the response data from Google PageSpeed Insights.
 
-#### callback(error)
-
-Type: `function`
+`url` and `options` is the same as `psi()`.
 
 
 ## CLI

cli.js

@@ -30,15 +30,13 @@ if (!cli.input[0]) {
   process.exit(1);
 }
 
-psi.output(cli.input[0], cli.flags, function (err, res) {
-  if (err) {
-    if (err.noStack) {
-      console.error(err.message);
-      process.exit(1);
-    } else {
-      throw err;
-    }
-  }
-
+psi.output(cli.input[0], cli.flags).then(function () {
   process.exit(0);
+}, function (err) {
+  if (err.noStack) {
+    console.error(err.message);
+    process.exit(1);
+  } else {
+    throw err;
+  }
 });

index.js

@@ -1,8 +1,10 @@
 'use strict';
+var Promise = require('pinkie-promise');
 var googleapis = require('googleapis');
 var prependHttp = require('prepend-http');
 var objectAssign = require('object-assign');
-var pagespeed = googleapis.pagespeedonline('v2').pagespeedapi.runpagespeed;
+var pify = require('pify');
+var pagespeed = pify(googleapis.pagespeedonline('v2').pagespeedapi.runpagespeed, Promise);
 var output = require('./lib/output');
 
 function handleOpts(url, opts) {
@@ -12,45 +14,26 @@ function handleOpts(url, opts) {
   return opts;
 }
 
-var psi = module.exports = function (url, opts, cb) {
-  if (typeof opts !== 'object') {
-      cb = opts;
+var psi = module.exports = function (url, opts) {
+  return Promise.resolve().then(function () {
+    if (typeof opts !== 'object') {
       opts = {};
-  }
-
-  if (!url) {
-    throw new Error('URL required');
-  }
-
-  if (typeof cb !== 'function') {
-    throw new Error('Callback required');
-  }
-
-  pagespeed(handleOpts(url, opts), function (err, response) {
-    if (err) {
-      err.noStack = true;
-      cb(err);
-      return;
     }
 
-    cb(null, response);
+    if (!url) {
+      throw new Error('URL required');
+    }
+
+    return pagespeed(handleOpts(url, opts));
   });
 };
 
-module.exports.output = function (url, opts, cb) {
+module.exports.output = function (url, opts) {
   if (typeof opts !== 'object') {
-      cb = opts;
-      opts = {};
+    opts = {};
   }
 
-  cb = cb || function () {};
-
-  psi(url, opts, function (err, data) {
-    if (err) {
-      cb(err);
-      return;
-    }
-
-    output(handleOpts(url, opts), data, cb);
+  return psi(url, opts).then(function (data) {
+    return output(handleOpts(url, opts), data);
   });
 };

lib/output.js

@@ -1,10 +1,10 @@
 'use strict';
+var Promise = require('pinkie-promise');
 var prettyBytes = require('pretty-bytes');
 var sortOn = require('sort-on');
 var humanizeUrl = require('humanize-url');
 var Download = require('download');
 var querystring = require('querystring');
-var writeFileSync = require('fs').writeFileSync;
 var THRESHOLD = 70;
 var RESOURCE_URL = 'https://developers.google.com/speed/pagespeed/insights/optimizeContents?';
 
@@ -60,32 +60,35 @@ function getReporter(format) {
   return require('./formats/' + format);
 }
 
-module.exports = function (parameters, response, cb) {
-  var renderer = getReporter(parameters.format);
-  var threshold = parameters.threshold || THRESHOLD;
-  var optimizedResoruceURL = RESOURCE_URL + querystring.stringify({url: response.id, strategy: parameters.strategy})
-
-  console.log(renderer(
-    overview(humanizeUrl(response.id), parameters.strategy, response.ruleGroups.SPEED.score),
-    statistics(response.pageStats),
-    ruleSetResults(response.formattedResults.ruleResults),
-    threshold
-  ));
-
-  if (parameters.optimized) {
-    console.log('\nHere are your optimized images: ', humanizeUrl(optimizedResoruceURL));
-  }
-
-  if (response.ruleGroups.SPEED.score < threshold) {
-    var err = new Error('Threshold of ' + threshold + ' not met with score of ' + response.ruleGroups.SPEED.score);
-    return cb(err);
-  }
-
-  if (parameters.download) {
-      new Download()
-          .get(optimizedResoruceURL)
-          .dest('.')
-          .rename('./optimized.zip')
-          .run(cb);
-  }
+module.exports = function (parameters, response) {
+  return Promise.resolve().then(function () {
+    var renderer = getReporter(parameters.format);
+    var threshold = parameters.threshold || THRESHOLD;
+    var optimizedResoruceURL = RESOURCE_URL + querystring.stringify({url: response.id, strategy: parameters.strategy});
+
+    console.log(renderer(
+      overview(humanizeUrl(response.id), parameters.strategy, response.ruleGroups.SPEED.score),
+      statistics(response.pageStats),
+      ruleSetResults(response.formattedResults.ruleResults),
+      threshold
+    ));
+
+    if (parameters.optimized) {
+      console.log('\nHere are your optimized images: ', humanizeUrl(optimizedResoruceURL));
+    }
+
+    if (response.ruleGroups.SPEED.score < threshold) {
+      var err = new Error('Threshold of ' + threshold + ' not met with score of ' + response.ruleGroups.SPEED.score);
+      throw err;
+    }
+
+    if (parameters.download) {
+      var download = new Download()
+        .get(optimizedResoruceURL)
+        .dest('.')
+        .rename('./optimized.zip');
+
+      return pify(download.run.bind(download), Promise)();
+    }
+  });
 };

package.json

@@ -33,20 +33,22 @@
     "size"
   ],
   "dependencies": {
-    "chalk": "^1.0.0",
-    "download": "^4.2.0",
-    "googleapis": "^2.0.3",
-    "humanize-url": "^1.0.0",
-    "lodash": "^3.2.0",
-    "meow": "^3.3.0",
-    "object-assign": "^2.0.0",
-    "prepend-http": "^1.0.0",
-    "pretty-bytes": "^1.0.1",
-    "repeating": "^1.1.1",
-    "sort-on": "^1.0.0",
+    "chalk": "^1.1.1",
+    "download": "^4.4.1",
+    "googleapis": "^2.1.6",
+    "humanize-url": "^1.0.1",
+    "lodash": "^3.10.1",
+    "meow": "^3.5.0",
+    "object-assign": "^4.0.1",
+    "pify": "^2.3.0",
+    "pinkie-promise": "^1.0.0",
+    "prepend-http": "^1.0.3",
+    "pretty-bytes": "^2.0.1",
+    "repeating": "^2.0.0",
+    "sort-on": "^1.2.2",
     "update-notifier": "^0.5.0"
   },
   "devDependencies": {
-    "mocha": "^2.0.1"
+    "mocha": "^2.3.3"
   }
 }

test/test.js

@@ -22,44 +22,44 @@ describe('Formatting', function () {
   });
 
   it('should correctly format PageSpeed Insights response', function () {
-    output({strategy: 'desktop'}, response);
-    assert(/Score:     88/.test(chalk.stripColor(this.formattedOutput)));
+    return output({strategy: 'desktop'}, response).then(function () {
+      assert(/Score:     88/.test(chalk.stripColor(this.formattedOutput)));
+    }.bind(this));
   });
 
   it('should format PageSpeed Insights response as TAP output', function () {
-    output({strategy: 'desktop', format: 'tap'}, response);
-    assert(/ok 1 - psi/.test(chalk.stripColor(this.formattedOutput)));
+    return output({strategy: 'desktop', format: 'tap'}, response).then(function () {
+      assert(/ok 1 - psi/.test(chalk.stripColor(this.formattedOutput)));
+    }.bind(this));
   });
 
   it('should format PageSpeed Insights response as JSON output', function () {
-    output({strategy: 'desktop', format: 'json'}, response);
-    assert(/"Score": 88/.test(chalk.stripColor(this.formattedOutput)));
+    return output({strategy: 'desktop', format: 'json'}, response).then(function () {
+      assert(/"Score": 88/.test(chalk.stripColor(this.formattedOutput)));
+    }.bind(this));
   });
 
-  it('should have an error in the callback if threshold is not met', function (done) {
-      output({threshold: 100}, response, function (err, result) {
-        assert.equal(err.name, 'Error', 'Expcted an error.');
-        done();
-      });
+  it('should have an error in the callback if threshold is not met', function () {
+    return output({threshold: 100}, response).catch(function (err) {
+      return err;
+    }).then(function (err) {
+      assert.equal(err.name, 'Error', 'Expected an error.');
+    });
   });
 });
 
 describe('API', function () {
   this.timeout(50000);
 
-  it('should get data from PageSpeed Insights', function (cb) {
-    psi('google.com', function (err, data) {
-      assert(!err, err);
+  it('should get data from PageSpeed Insights', function () {
+    return psi('google.com').then(function (data) {
       assert.strictEqual(data.title, 'Google');
-      cb();
     });
   });
 
-  it('should support options', function (cb) {
-    psi('google.com', {locale: 'no'}, function (err, data) {
-      assert(!err, err);
+  it('should support options', function () {
+    return psi('google.com', {locale: 'no'}).then(function (data) {
       assert.strictEqual(data.formattedResults.locale, 'no');
-      cb();
     });
   });
 });