From 54f901f131282ea3ca0668d0ec54cede7a45561e Mon Sep 17 00:00:00 2001
From: Sebastian McKenzie <sebmck@gmail.com>
Date: Fri, 7 Nov 2014 13:16:26 +1100
Subject: [PATCH] require: add missing blacklistTests, implement opts.whitelist
 and opts.only - closes #125

Conflicts:
	lib/6to5/register.js
---
 README.md            | 25 ++++++++++++--------
 lib/6to5/register.js | 55 +++++++++++++++++++++++++++++++++++++-------
 2 files changed, 62 insertions(+), 18 deletions(-)

diff --git a/README.md b/README.md
index f74281f289..06e9d29c4b 100644
--- a/README.md
+++ b/README.md
@@ -190,21 +190,26 @@ require("6to5/register");
 ```
 
 **NOTE:** By default all requires to `node_modules` will be ignored. You can
-override this by passing an ignore regex via:
+override this by passing an ignore regex with`.
 
-```javascript
-require("6to5/register")(/regex/);
-```
-
-You can also customise the file extensions that the require hook will use via:
+##### Options
 
 ```javascript
 require("6to5/register")({
-  // optional ignore regex
-  ignoreRegex: /regex/,
+  // Optional ignore regex - if any filenames **do** match this regex then they
+  // aren't compiled
+  ignore: /regex/,
 
-  // this will remove the currently hooked extensions of .es6 and .js so you'll
-  // have to add them back if you want them to be used again
+  // Optional only regex - if any filenames **don't** match this regex then they
+  // aren't compiled
+  only: /my_es6_folder/,
+
+  // See options above for usage
+  whitelist: [],
+  blacklist: [],
+
+  // This will remove the currently hooked extensions of .es6 and .js so you'll
+  // have to add them back if you want them to be used again.
   extensions: [".js", ".es6"]
 });
 ```
diff --git a/lib/6to5/register.js b/lib/6to5/register.js
index 840039b385..1ccadaec56 100644
--- a/lib/6to5/register.js
+++ b/lib/6to5/register.js
@@ -20,20 +20,57 @@ sourceMapSupport.install({
 
 //
 
+var blacklist  = [];
+
+var blacklistTest = function (transformer, code) {
+  try {
+    if (_.isFunction(code)) {
+      code();
+    } else {
+      new Function(code);
+    }
+    blacklist.push(transformer);
+  } catch (err) {
+    if (err.name !== "SyntaxError") throw err;
+  }
+};
+
+blacklistTest("arrayComprehension", "var foo = [for (foo of bar) foo * foo];");
+blacklistTest("arrowFunctions", "var foo = x => x * x;");
+blacklistTest("classes", "class Foo {}");
+blacklistTest("computedPropertyNames", "var foo = { [foo]: bar };");
+//blacklistTest("constants", "const foo = 0;");
+blacklistTest("defaultParamaters", "var foo = function (bar = 0) {};");
+blacklistTest("destructuring", "var { x, y } = { x: 0, y: 0 };");
+blacklistTest("forOf", "for (var foo of bar) {}");
+blacklistTest("generators", "function* foo() {}");
+blacklistTest("letScoping", "let foo = 0;");
+blacklistTest("modules", 'import foo from "from";');
+blacklistTest("propertyMethodAssignment", "{ get foo() {} }");
+blacklistTest("propertyNameShorthand", "var foo = { x, y };");
+blacklistTest("restParameters", "function foo(...bar) {}");
+blacklistTest("spread", "foo(...bar);");
+blacklistTest("templateLiterals", "`foo`");
+blacklistTest("unicodeRegex", function () { new RegExp("foo", "u"); });
+
+//
+
 var ignoreRegex = /node_modules/;
-var blacklist   = [];
+var onlyRegex;
+var whitelist   = [];
 var exts        = {};
 var maps        = {};
 var old         = require.extensions[".js"];
 
 var loader = function (m, filename) {
-  if (ignoreRegex && ignoreRegex.test(filename)) {
+  if ((ignoreRegex && ignoreRegex.test(filename)) || (onlyRegex && !onlyRegex.test(filename))) {
     return old.apply(this, arguments);
   }
 
   var result = to5.transformFileSync(filename, {
-    sourceMap: true,
-    blacklist: blacklist
+    whitelist: whitelist,
+    blacklist: blacklist,
+    sourceMap: true
   });
 
   maps[filename] = result.map;
@@ -57,14 +94,16 @@ var hookExtensions = function (_exts) {
 hookExtensions([".es6", ".js"]);
 
 module.exports = function (opts) {
+  // normalise options
   opts = opts || {};
-  if (_.isRegExp(opts)) opts = { ignoreRegex: opts };
+  if (_.isRegExp(opts)) opts = { ignore: opts };
+  opts.ignore = opts.ignore || opts.ignoreRegex;
 
-  if (opts.ignoreRegex != null) {
-    ignoreRegex = opts.ignoreRegex;
-  }
+  if (opts.only != null) onlyRegex = opts.only;
+  if (opts.ignore != null) ignoreRegex = opts.ignore;
 
   if (opts.extensions) hookExtensions(opts.extensions);
 
   if (opts.blacklist) blacklist = opts.blacklist;
+  if (opts.whitelist) whitelist = opts.whitelist;
 };