feat(Bluebird Removal): Migrate detect function to native promises (#86)

lib/detect.js

@@ -1,21 +1,19 @@
 'use strict';
 
 var fs      = require('fs');
-var Promise = require('bluebird');
-var pread   = Promise.promisify(fs.read, { multiArgs: true });
+var util = require('util');
+var pread   = util.promisify(fs.read);
 
 var DETECT_LENGTH = 16;
 
 //Determines the appropriate plugin to use for the given file descriptor.
-module.exports = function (fd, plugins) {
-  return pread(fd, Buffer.alloc(DETECT_LENGTH), 0, DETECT_LENGTH, 0)
-  .spread(function (bytesRead, buffer) {
-    for (var i = 0; i < plugins.length; i++) {
-      var plugin = plugins[i];
-      if (plugin.detect(buffer)) {
-        return plugin;
-      }
+module.exports = async function (fd, plugins) {
+  const readObject = await pread(fd, Buffer.alloc(DETECT_LENGTH), 0, DETECT_LENGTH, 0);
+  for (var i = 0; i < plugins.length; i++) {
+    var plugin = plugins[i];
+    if (plugin.detect(readObject.buffer)) {
+      return plugin;
     }
-    throw new Error('File type not supported');
-  });
+  }
+  throw new Error('File type not supported');
 };

package.json

@@ -10,6 +10,7 @@
     "build": "tsc",
     "test": "jest",
     "lint": "eslint .",
+    "lint:fix": "eslint --fix .",
     "lint:file": "eslint"
   },
   "repository": {