Throw if templating a file fails

Previously, if an error was thrown during the template rendering
process, the error was simply swallowed. This was likely to avoid
errors when attempting to template a binary file, since the byte
stream, when converted to a string, could contain template markers.

Adds the isbinaryfile package to detect if the file is binary. If
so, it skips templating entirely. If not, it attempts to template
the file, and allows exceptions to reject the render promise.

This happened to expose some tests that should have been failing
around the http-proxy generators (the tests were not supplying
enough arguments). Fixes those tests too.

lib/models/file-info.js

@@ -3,9 +3,11 @@
 var fs           = require('fs');
 var Promise      = require('../ext/promise');
 var readFile     = Promise.denodeify(fs.readFile);
+var lstat        = Promise.denodeify(fs.stat);
 var chalk        = require('chalk');
 var EditFileDiff = require('./edit-file-diff');
 var EOL          = require('os').EOL;
+var isBinaryFile = require('isbinaryfile');
 
 function processTemplate(content, context) {
   return require('lodash/string/template')(content)(context);
@@ -84,11 +86,13 @@ FileInfo.prototype.render = function() {
       context = this.templateVariables;
   if (!this.rendered) {
     this.rendered = readFile(path).then(function(content){
-      try {
-        return processTemplate(content.toString(), context);
-      } catch (error) {
-        return content.toString();
-      }
+      return lstat(path).then(function(fileStat) {
+        if (isBinaryFile(content, fileStat.size)) {
+          return content;
+        } else {
+          return processTemplate(content.toString(), context);
+        }
+      });
     });
   }
   return this.rendered;

package.json

@@ -135,6 +135,7 @@
     "chai-as-promised": "^4.3.0",
     "ember-cli-ncp": "1.0.2",
     "github": "^0.2.3",
+    "isbinaryfile": "^2.0.3",
     "mocha": "^2.2.1",
     "mocha-jshint": "1.0.0",
     "multiline": "^1.0.2",

tests/acceptance/destroy-test.js

@@ -547,7 +547,7 @@ describe('Acceptance: ember destroy', function() {
 
   it('http-proxy foo', function() {
     this.timeout(20000);
-    var commandArgs = ['http-proxy', 'foo'];
+    var commandArgs = ['http-proxy', 'foo', 'bar'];
     var files       = ['server/proxies/foo.js'];
 
     return assertDestroyAfterGenerate(commandArgs, files);

tests/acceptance/pods-destroy-test.js

@@ -585,7 +585,7 @@ describe('Acceptance: ember destroy pod', function() {
   });
 
   it('http-proxy foo --pod', function() {
-    var commandArgs = ['http-proxy', 'foo', '--pod'];
+    var commandArgs = ['http-proxy', 'foo', 'bar', '--pod'];
     var files       = ['server/proxies/foo.js'];
 
     return assertDestroyAfterGenerate(commandArgs, files);

tests/unit/models/file-info-test.js

@@ -53,16 +53,19 @@ describe('Unit - FileInfo', function(){
     });
   });
 
-  it('falls back to raw text if template throws', function(){
+  it('rejects if templating throws', function(){
     var templateWithUndefinedVariable = path.resolve(__dirname,
       '../../fixtures/blueprints/with-templating/files/with-undefined-variable.txt');
     var options = {};
     assign(options, validOptions, { inputPath: templateWithUndefinedVariable });
     var fileInfo = new FileInfo(options);
 
-    return fileInfo.render().then(function(output){
-      expect(output.trim()).to.equal('Howdy <%= enemy %>',
-        'expects to fall back to raw text');
+    return fileInfo.render().then(function() {
+      throw new Error('FileInfo.render should reject if templating throws');
+    }).catch(function(e) {
+      if (!e.toString().match(/ReferenceError/)) {
+        throw e;
+      }
     });
   });