CLI: -v option for displaying current version

Fixes #431

bin/mustache

@@ -8,7 +8,7 @@ var pkg = require('../package');
 var viewArg = process.argv[2];
 var templateArg = process.argv[3];
 
-if (process.argv.indexOf('--version') > -1) {
+if (hasVersionArg()) {
   return console.log(pkg.version);
 }
 
@@ -87,3 +87,9 @@ function isStdin(viewArg) {
 function wasNotFound(err) {
   return err.code && err.code === 'ENOENT';
 }
+
+function hasVersionArg() {
+  return ['--version', '-v'].some(function(opt) {
+    return process.argv.indexOf(opt) > -1;
+  });
+}

test/cli-test.js

@@ -35,6 +35,13 @@ describe('Mustache CLI', function () {
     });
   });
 
+  it('writes module version into stdout when runned with -v', function(done){
+    exec('bin/mustache -v', function(err, stdout, stderr) {
+      assert.notEqual(stdout.indexOf(moduleVersion), -1);
+      done();
+    });
+  });
+
   it('writes rendered template into stdout when successfull', function(done) {
     exec('bin/mustache test/_files/cli.json test/_files/cli.mustache', function(err, stdout, stderr) {
       assert.equal(err, null);