Add promise support

index.js

@@ -1,11 +1,11 @@
 'use strict'
 
-const Finder = require('./lib/finder')
+const { fromCallback } = require('catering')
 const after = require('after')
+const Finder = require('./lib/finder')
 
-const DEFAULTS = {
-  browsers: require('./lib/browsers')
-}
+const DEFAULTS = { browsers: require('./lib/browsers') }
+const kPromise = Symbol('promise')
 
 module.exports = function detect (names, opts, done) {
   if (typeof names === 'string') {
@@ -23,11 +23,14 @@ module.exports = function detect (names, opts, done) {
     opts = Object.assign({}, DEFAULTS, opts)
   }
 
+  done = fromCallback(done, kPromise)
+
   if (!names || !names.length) {
     names = Object.keys(opts.browsers)
   }
 
   const result = []
+  const finish = (err) => err ? done(err) : done(null, result, totalMethods)
   const next = after(names.length, finish)
 
   // For debugging: count the number
@@ -47,8 +50,5 @@ module.exports = function detect (names, opts, done) {
     })
   })
 
-  function finish (err) {
-    if (err) done(err)
-    else done(err, result, totalMethods)
-  }
+  return done[kPromise]
 }

package.json

@@ -18,6 +18,7 @@
   },
   "dependencies": {
     "after": "^0.8.2",
+    "catering": "^2.1.0",
     "chalk": "^4.1.2",
     "debug": "^4.1.0",
     "existent": "^1.0.1",

readme.md

@@ -37,7 +37,10 @@ detect(function (err, browsers) {
   console.log(browsers)
 })
 
-// Chrome and Firefox
+// All browsers with promise
+const browsers = await detect()
+
+// Search only for Chrome and Firefox
 detect(['chrome', 'firefox'], function (err, browsers) {
   if (err) throw err
 
@@ -50,9 +53,9 @@ detect(['chrome', 'firefox'], function (err, browsers) {
 
 ## API
 
-### `detect([names, ]callback)`
+### `detect([names][, callback])`
 
-`names` is an array of browser names you want to find. If omitted or empty, it will detect _[everything](http://youtu.be/k1yvvNvlXtg)_. The `callback` receives an error if any and an array of `results`. A result is excluded if its path has no `.exe` extension or if its version could not be read.
+`names` is an array of browser names you want to find. If omitted or empty, it will detect _[everything](http://youtu.be/k1yvvNvlXtg)_. The `callback` receives an error if any and an array of `results`. A result is excluded if its path has no `.exe` extension or if its version could not be read. If no callback is provided, a promise is returned.
 
 Each `result` is an object with the following properties:
 

test.js

@@ -351,6 +351,18 @@ test('detect all', function (t) {
   })
 })
 
+test('detect all with promise', async function (t) {
+  const results = await detect()
+  const names = results.map(b => b.name)
+  const withVersions = results.filter(hasVersion).length
+
+  t.ok(names.indexOf('chrome') >= 0, 'found chrome')
+  t.ok(names.indexOf('firefox') >= 0, 'found firefox')
+  t.ok(names.indexOf('ie') >= 0, 'found ie')
+
+  t.equal(withVersions, results.length, 'have version numbers')
+})
+
 test('detect chrome', function (t) {
   detect('chrome', function (err, results) {
     t.ifError(err, 'no error')
@@ -370,6 +382,20 @@ test('detect chrome', function (t) {
   })
 })
 
+test('detect chrome with promise', async function (t) {
+  const results = await detect('chrome')
+  const names = results.filter(b => b.name === 'chrome')
+  t.equal(names.length, results.length, 'have names')
+
+  const versions = results.filter(hasVersion)
+  t.equal(versions.length, results.length, 'have version numbers')
+
+  if (argv.canary) {
+    const msg = 'found ' + results.length + ' chrome versions'
+    t.ok(results.length >= 2, msg)
+  }
+})
+
 test('detect chrome and firefox', function (t) {
   t.plan(4)
 
@@ -385,6 +411,16 @@ test('detect chrome and firefox', function (t) {
   })
 })
 
+test('detect chrome and firefox with promise', async function (t) {
+  const results = await detect(['chrome', 'firefox'])
+  const names = results.map(b => b.name)
+  const withVersions = results.filter(hasVersion).length
+
+  t.ok(names.indexOf('chrome') >= 0, 'found chrome')
+  t.ok(names.indexOf('firefox') >= 0, 'found firefox')
+  t.ok(withVersions >= 2, 'have version numbers')
+})
+
 maybe(argv.opera)('detect all opera versions', function (t) {
   t.plan(3)
 
@@ -445,7 +481,7 @@ test('no result asynchronicity', function (t) {
 
   let async = false
 
-  detect({ browsers: browsers }, function (err, results) {
+  detect({ browsers }, function (err, results) {
     t.ifError(err, 'no error')
     t.equal(results.length, 0)
     t.equal(async, true)
@@ -454,6 +490,20 @@ test('no result asynchronicity', function (t) {
   async = true
 })
 
+test('no result with promise', async function (t) {
+  const browsers = {
+    beep: {
+      bin: 'beep.exe',
+      find: function () {
+        this.file()
+      }
+    }
+  }
+
+  const results = await detect({ browsers })
+  t.equal(results.length, 0)
+})
+
 function hasVersion (b) {
   return b.version && b.version.match(/[\d.]+/)
 }