Created command line tool

README.md

@@ -461,6 +461,36 @@ These may be built using [Rake](http://rake.rubyforge.org/) and one of the follo
     $ rake yui3
     $ rake qooxdoo
 
+## Command line tool
+
+mustache.js is shipped with a node based command line tool. It might be installed as a global tool on your computer to render a mustache template of some kind
+
+```bash
+$ npm install -g mustache
+$ mustache dataView.json myTemplate.mustache > output.html
+
+# also supports stdin
+$ cat dataView.json | mustache - myTemplate.mustache > output.html
+```
+
+or as a package.json `devDependency` in a build process maybe?
+
+```bash
+$ npm install mustache --save-dev
+```
+```json
+{
+  "scripts": {
+    "build": "mustache dataView.json myTemplate.mustache > public/output.html"
+  }
+}
+```
+```bash
+$ npm run build
+```
+
+The command line tool is basically a wrapper around `Mustache.render` so you get all the aformentioned features.
+
 ## Testing
 
 In order to run the tests you'll need to install [node](http://nodejs.org/).

bin/mustache

@@ -0,0 +1,89 @@
+#!/usr/bin/env node
+
+var fs = require('fs');
+
+var Mustache = require('..');
+var pkg = require('../package');
+
+var viewArg = process.argv[2];
+var templateArg = process.argv[3];
+
+if (process.argv.indexOf('--version') > -1) {
+  return console.log(pkg.version);
+}
+
+if (!templateArg || !viewArg) {
+  console.error('Syntax: mustache <view> <template>');
+  process.exit(1);
+}
+
+run(readView, readTemplate, render, toStdout);
+
+/**
+ * Runs a list of functions as a waterfall.
+ * Functions are runned one after the other in order, providing each
+ * function the returned values of all the previously invoked functions.
+ * Each function is expected to exit the process if an error occurs.
+ */
+function run(/*args*/) {
+  var values = [];
+  var fns = Array.prototype.slice.call(arguments);
+
+  function invokeNextFn(val) {
+    values.unshift(val);
+    if (fns.length == 0) return;
+    invoke(fns.shift());
+  }
+
+  function invoke(fn) {
+    fn.apply(null, [invokeNextFn].concat(values));
+  }
+
+  invoke(fns.shift());
+}
+
+function readView(cb) {
+  var view = isStdin(viewArg) ? process.openStdin() : fs.createReadStream(viewArg);
+
+  streamToStr(view, function(str) {
+    cb(JSON.parse(str));
+  });
+}
+
+function readTemplate(cb) {
+  var template = fs.createReadStream(templateArg);
+  streamToStr(template, cb);
+}
+
+function render(cb, templateStr, jsonView) {
+  cb(Mustache.render(templateStr, jsonView));
+}
+
+function toStdout(cb, str) {
+  cb(process.stdout.write(str));
+}
+
+function streamToStr(stream, cb) {
+  var data = '';
+
+  stream.on('data', function(chunk) {
+    data += chunk;
+  }).once('end', function() {
+    cb(data.toString());
+  }).on('error', function(err) {
+    if (wasNotFound(err)) {
+      console.error('Could not find file:', err.path);
+    } else {
+      console.error('Error while reading file:', err.message);
+    }
+    process.exit(1);
+  });
+}
+
+function isStdin(viewArg) {
+  return viewArg === '-';
+}
+
+function wasNotFound(err) {
+  return err.code && err.code === 'ENOENT';
+}

package.json

@@ -14,6 +14,9 @@
     "ejs"
   ],
   "main": "./mustache.js",
+  "bin": {
+    "mustache": "./bin/mustache"
+  },
   "volo": {
     "url": "https://raw.github.com/janl/mustache.js/{version}/mustache.js"
   },

test/_files/cli.json

@@ -0,0 +1,3 @@
+{
+  "name": "LeBron"
+}

test/_files/cli.mustache

@@ -0,0 +1 @@
+Howdy {{name}}, CLI rox

test/_files/cli.txt

@@ -0,0 +1 @@
+Howdy LeBron, CLI rox

test/cli-test.js

@@ -0,0 +1,70 @@
+require('./helper');
+
+var fs = require('fs');
+var path = require('path');
+var _files = path.join(__dirname, '_files');
+var cliTxt = path.resolve(_files, 'cli.txt');
+var moduleVersion = require('../package').version;
+
+var exec = require('child_process').exec;
+
+describe('Mustache CLI', function () {
+
+  var expectedOutput;
+
+  before(function(done) {
+    fs.readFile(cliTxt, function onFsEnd(err, data) {
+      if (err) return done(err);
+
+      expectedOutput = data.toString();
+      done();
+    });
+  });
+
+  it('writes syntax hints into stderr when runned with wrong number of arguments', function(done) {
+    exec('bin/mustache', function(err, stdout, stderr) {
+      assert.notEqual(stderr.indexOf('Syntax'), -1);
+      done();
+    });
+  });
+
+  it('writes module version into stdout when runned with --version', function(done){
+    exec('bin/mustache --version', 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);
+      assert.equal(stderr, '');
+      assert.equal(stdout, expectedOutput);
+      done();
+    });
+  });
+
+  it('reads view data from stdin when first argument equals "-"', function(done){
+    exec('cat test/_files/cli.json | bin/mustache - test/_files/cli.mustache', function(err, stdout, stderr) {
+      assert.equal(err, null);
+      assert.equal(stderr, '');
+      assert.equal(stdout, expectedOutput);
+      done();
+    });
+  });
+
+  it('writes it couldnt find template into stderr when second argument doesnt resolve to a file', function(done) {
+    exec('bin/mustache test/_files/cli.json test/_files/non-existing-template.mustache', function(err, stdout, stderr) {
+      assert.notEqual(stderr.indexOf('Could not find file: test/_files/non-existing-template.mustache'), -1);
+      done();
+    });
+  });
+
+  it('writes it couldnt find view into stderr when first argument doesnt resolve to a file', function(done) {
+    exec('bin/mustache test/_files/non-existing-view.json test/_files/cli.mustache', function(err, stdout, stderr) {
+      assert.notEqual(stderr.indexOf('Could not find file: test/_files/non-existing-view.json'), -1);
+      done();
+    });
+  });
+
+});