add support for an optional runtime - closes #129

lib/6to5/file.js

@@ -5,7 +5,6 @@ var SHEBANG_REGEX = /^\#\!.*/;
 var transform = require("./transformation/transform");
 var generate  = require("./generation/generator");
 var Scope     = require("./traverse/scope");
-var acorn     = require("acorn-6to5");
 var util      = require("./util");
 var t         = require("./types");
 var _         = require("lodash");
@@ -19,6 +18,8 @@ function File(opts) {
   this.ast          = {};
 }
 
+File.declarations = ["extends", "class-props", "slice"];
+
 File.normaliseOptions = function (opts) {
   opts = opts || {};
 
@@ -28,7 +29,8 @@ File.normaliseOptions = function (opts) {
     whitelist:  [],
     sourceMap:  false,
     filename:   "unknown",
-    modules:    "common"
+    modules:    "common",
+    runtime:    false
   });
 
   _.defaults(opts, {
@@ -36,6 +38,10 @@ File.normaliseOptions = function (opts) {
     sourceMapName:  opts.filename
   });
 
+  if (opts.runtime === true) {
+    opts.runtime = "to5Runtime";
+  }
+
   transform._ensureTransformerNames("blacklist", opts.blacklist);
   transform._ensureTransformerNames("whitelist", opts.whitelist);
 
@@ -43,18 +49,18 @@ File.normaliseOptions = function (opts) {
 };
 
 File.prototype.getModuleFormatter = function (type) {
-  var ModuleLoader = transform.moduleFormatters[type];
+  var ModuleFormatter = transform.moduleFormatters[type];
 
-  if (!ModuleLoader) {
+  if (!ModuleFormatter) {
     var loc = util.resolve(type);
-    if (loc) ModuleLoader = require(loc);
+    if (loc) ModuleFormatter = require(loc);
   }
 
-  if (!ModuleLoader) {
+  if (!ModuleFormatter) {
     throw new ReferenceError("unknown module formatter type " + type);
   }
 
-  return new ModuleLoader(this);
+  return new ModuleFormatter(this);
 };
 
 File.prototype.parseShebang = function (code) {
@@ -70,13 +76,26 @@ File.prototype.parseShebang = function (code) {
 };
 
 File.prototype.addDeclaration = function (name) {
+  if (!_.contains(File.declarations, name)) {
+    throw new ReferenceError("unknown declaration " + name);
+  }
+
   var declar = this.declarations[name];
   if (declar) return declar.uid;
 
+  var ref;
+  var runtimeNamespace = this.opts.runtime;
+  if (runtimeNamespace) {
+    name = t.identifier(t.toIdentifier(name));
+    return t.memberExpression(t.identifier(runtimeNamespace), name);
+  } else {
+    ref = util.template(name);
+  }
+
   var uid = t.identifier(this.generateUid(name));
   this.declarations[name] = {
     uid: uid,
-    node: util.template(name)
+    node: ref
   };
   return uid;
 };
@@ -118,7 +137,7 @@ File.prototype.generate = function () {
   var opts = this.opts;
   var ast  = this.ast;
 
-  var result = generate(this.code, ast, opts);
+  var result = generate(ast, opts, this.code);
 
   if (this.shebang) {
     // add back shebang
@@ -133,7 +152,10 @@ File.prototype.generate = function () {
 };
 
 File.prototype.generateUid = function (name, scope) {
+  name = t.toIdentifier(name);
+
   scope = scope || this.scope;
+
   var uid;
   do {
     uid = this._generateUid(name);
@@ -142,17 +164,6 @@ File.prototype.generateUid = function (name, scope) {
 };
 
 File.prototype._generateUid = function (name) {
-  // replace all non-valid identifiers with dashes
-  name = name.replace(/[^a-zA-Z0-9]/g, "-");
-
-  // remove all dashes and numbers from start of name
-  name = name.replace(/^[-0-9]+/, "");
-
-  // camel case
-  name = name.replace(/[-_\s]+(.)?/g, function (match, c) {
-    return c ? c.toUpperCase() : "";
-  });
-
   var uids = this.uids;
   var i = uids[name] || 1;
 

lib/6to5/index.js

@@ -2,6 +2,8 @@ var transform = require("./transformation/transform");
 var fs        = require("fs");
 var _         = require("lodash");
 
+exports.runtime = require("./runtime");
+
 exports.register = function (opts) {
   var register = require("./register");
   if (opts != null) register(opts);

lib/6to5/runtime.js

@@ -0,0 +1,44 @@
+var generator = require("./generation/generator");
+var util      = require("./util");
+var File      = require("./file");
+var t         = require("./types");
+var _         = require("lodash");
+
+module.exports = function (namespace) {
+  var body = [];
+  var container = t.functionExpression(null, [], t.blockStatement(body));
+
+  var tree = {
+    type: "Program",
+    body: [t.expressionStatement(t.callExpression(container, []))]
+  };
+
+  body.push(t.variableDeclaration("var", [
+    t.variableDeclarator(t.identifier("self"), t.conditionalExpression(
+      t.binaryExpression("===",
+        t.unaryExpression("typeof", t.identifier("global"), true),
+        t.literal("undefined")
+      ),
+      t.identifier("window"),
+      t.identifier("global"))
+    )
+  ]));
+
+  var namespace = t.identifier(namespace || "to5Runtime");
+
+  body.push(t.variableDeclaration("var", [
+    t.variableDeclarator(
+      namespace,
+      t.assignmentExpression("=", t.memberExpression(t.identifier("self"), namespace), t.objectExpression([]))
+    )
+  ]));
+
+  _.each(File.declarations, function (name) {
+    var key = t.identifier(t.toIdentifier(name));
+    body.push(t.expressionStatement(
+      t.assignmentExpression("=", t.memberExpression(namespace, key), util.template(name))
+    ));
+  });
+
+  return generator(tree).code;
+};