feat(node-module): Expose galen path as promise via module

see #47

core/index.js

@@ -0,0 +1,5 @@
+var helper = require('./lib/helper');
+
+module.exports = {
+  galenPath: helper.galenPath
+};

core/lib/helper.js

@@ -3,8 +3,8 @@
  * installed.
  */
 
-var fs = require('fs');
-var path = require('path');
+var fs = require('fs'),
+  path = require('path');
 
 
 /**
@@ -13,7 +13,7 @@ var path = require('path');
  */
 try {
   exports.path = path.resolve(__dirname, require('./location').location);
-} catch(e) {
+} catch (e) {
   // Must be running inside install script.
   exports.path = null;
 }
@@ -58,3 +58,26 @@ if (exports.path) {
     // We did our best. Likely because phantomjs was already installed.
   }
 }
+
+exports.galenPath = function () {
+  return new Promise(function (resolve, reject) {
+
+    galenPath = path.resolve(__dirname + '/../node_modules/galenframework/bin/galen' + (process.platform === 'win32' ? '.cmd' : ''));
+    fs.stat(galenPath, function (err) {
+      // resolve for NPM3+
+      if (err) {
+        galenPath = path.resolve(__dirname + '/../../galenframework/bin/galen' + (process.platform === 'win32' ? '.cmd' : ''));
+        fs.stat(galenPath, function (err) {
+          // resolve for NPM3+
+          if (err) {
+            reject('Cannot find Galenframework at ' + galenPath);
+          } else {
+            resolve(galenPath);
+          }
+        });
+      } else {
+        resolve(galenPath);
+      }
+    });
+  });
+}

core/package.json

@@ -28,6 +28,7 @@
   "bin": {
     "galen": "bin/galen"
   },
+  "main":"index",
   "dependencies": {
     "adm-zip": "0.4.7",
     "fs-extra": "0.23.0",