clean up system module formatter

lib/6to5/transformation/modules/_default.js

@@ -5,12 +5,11 @@ var util     = require("../../util");
 var t        = require("../../types");
 var _        = require("lodash");
 
-function DefaultFormatter(file) {
-  this.exports = [];
-  this.file    = file;
+function DefaultFormatter(file, illegalRemapping) {
+  this.file = file;
 
   this.localExports = this.getLocalExports();
-  this.remapAssignments();
+  this.remapAssignments(illegalRemapping);
 }
 
 DefaultFormatter.prototype.getLocalExports = function () {
@@ -28,26 +27,42 @@ DefaultFormatter.prototype.getLocalExports = function () {
   return localExports;
 };
 
-DefaultFormatter.prototype.remapAssignments = function () {
+DefaultFormatter.prototype.remapAssignments = function (illegal) {
   var localExports = this.localExports;
 
+  var remap = function (node) {
+    return t.assignmentExpression(
+      "=",
+      node.left,
+      t.assignmentExpression(
+        node.operator,
+        t.memberExpression(t.identifier("exports"), node.left),
+        node.right
+      )
+    );
+  };
+
+  var throwIllegal = function (node) {
+    // todo!!
+  };
+
+  var isLocalReference = function (node, scope) {
+    var left = node.left;
+    var name = left.name;
+    return t.isIdentifier(left) && localExports[name] && localExports[name] === scope.get(name, true);
+  };
+
   traverse(this.file.ast, {
     enter: function (node, parent, scope) {
       if (t.isExportDeclaration(node)) return false;
 
       if (t.isAssignmentExpression(node)) {
-        var left = node.left;
-        var name = left.name;
-        if (t.isIdentifier(left) && localExports[name] && localExports[name] === scope.get(name, true)) {
-          return t.assignmentExpression(
-            "=",
-            left,
-            t.assignmentExpression(
-              node.operator,
-              t.memberExpression(t.identifier("exports"), left),
-              node.right
-            )
-          );
+        if (isLocalReference(node, scope)) {
+          if (illegal) {
+            throwIllegal(node);
+          } else {
+            return remap(node);
+          }
         }
       }
     }

lib/6to5/transformation/modules/system.js

@@ -1,73 +1,64 @@
 module.exports = SystemFormatter;
 
-var util     = require("../../util");
-var t        = require("../../types");
-var traverse = require("../../traverse");
-var _        = require("lodash");
+var DefaultFormatter = require("./_default");
+var traverse         = require("../../traverse");
+var util             = require("../../util");
+var t                = require("../../types");
+var _                = require("lodash");
 
 var SETTER_MODULE_NAMESPACE        = t.identifier("m");
 var PRIVATE_MODULE_NAME_IDENTIFIER = t.identifier("__moduleName");
-var DEFAULT_IDENTIFIER             = t.identifier("default");
 var NULL_SETTER                    = t.literal(null);
 
 function SystemFormatter(file) {
-  this.moduleNameLiteral  = null;
+  DefaultFormatter.call(this, file, true);
+
   this.exportedStatements = [];
   this.moduleDependencies = {};
   this.importedVariables  = {};
-
+  this.moduleNameLiteral  = t.literal(this.getModuleName());
   this.exportIdentifier   = file.generateUidIdentifier("export");
-  this.file               = file;
-
-  /**
-   * @type Function
-   * @param {Array} args - The arguments of the "_export(...args)" function
-   * @return {Object} The expression statement with the call expression.
-   */
-  this._makeExportStatements = _.compose(
-    t.expressionStatement,
-    // will generate the call expression : _export(...args)
-    _.partial(t.callExpression, this.exportIdentifier)
-  );
 }
 
-SystemFormatter.prototype.import =
-  SystemFormatter.prototype.export = function (node, nodes) {
-    nodes.push(node);
-  };
+util.inherits(SystemFormatter, DefaultFormatter);
+
+SystemFormatter.prototype.importDeclaration =
+SystemFormatter.prototype.exportDeclaration = function (node, nodes) {
+  nodes.push(node);
+};
 
 SystemFormatter.prototype.importSpecifier =
-  SystemFormatter.prototype.exportSpecifier = function (specifier, node, nodes) {
-    if (!nodes.length) nodes.push(node);
-  };
+SystemFormatter.prototype.exportSpecifier = function (specifier, node, nodes) {
+  if (!nodes.length) nodes.push(node);
+};
+
+SystemFormatter.prototype._makeExportStatements = function (args) {
+  return t.expressionStatement(t.callExpression(this.exportIdentifier, args));
+};
 
 SystemFormatter.prototype.transform = function (ast) {
-
-  var systemTransform = this;
-
-  // extract the module name
-  this.moduleNameLiteral = t.literal(
-    this.file.opts.filename.replace(/^.*\//, "").replace(/\..*$/, "")
-  );
+  var self = this;
 
   // Post extraction of the import/export declaration
-  traverse(ast, function (node) {
-    var replacementNode = null;
+  traverse(ast, {
+    enter: function (node) {
+      var replacementNode = null;
 
-    /**
-     * Process the current node with an extractor.
-     * @param {Function} extractor Extract the node data
-     * @returns {*} Can be a `node` (for replacement), void 0 (for removing)
-     *   or false.
-     */
-    function processTheNode(extractor) {
-      var result = extractor.call(systemTransform, node);
-      result = (result === void 0) ? [] : result;
-      replacementNode = result || replacementNode;
-      return !!replacementNode;
-    }
+      /**
+       * Process the current node with an extractor.
+       *
+       * @param {Function} extractor Extract the node data
+       * @returns {*} Can be a `node` (for replacement), undefined (for removing) or false.
+       */
 
-    _.some([
+      function processTheNode(extractor) {
+        var result = extractor.call(self, node);
+        result = (result === undefined) ? [] : result;
+        replacementNode = result || replacementNode;
+        return !!replacementNode;
+      }
+
+      _.some([
         // Import
         SystemFormatter.prototype._extractImportSpecifiers,
         SystemFormatter.prototype._extractImport,
@@ -77,11 +68,10 @@ SystemFormatter.prototype.transform = function (ast) {
         SystemFormatter.prototype._extractExportVariableDeclaration,
         SystemFormatter.prototype._extractExportFunctionDeclaration,
         SystemFormatter.prototype._extractExportSpecifiers
-      ],
-      processTheNode
-    );
+      ], processTheNode);
 
-    return replacementNode;
+      return replacementNode;
+    }
   });
 
   // Other
@@ -91,32 +81,24 @@ SystemFormatter.prototype.transform = function (ast) {
   this._wrapInSystemRegisterCallExpression(ast);
 };
 
-//
 // Import extraction
-//
 
 SystemFormatter.prototype._extractImportSpecifiers = function (node) {
+  var self = this;
 
-  var systemTransform = this;
-
-  if (!(t.isImportDeclaration(node) && node.specifiers && node.specifiers.length )) {
+  if (!(t.isImportDeclaration(node) && node.specifiers && node.specifiers.length)) {
     return false;
   }
 
   _.each(node.specifiers, function (specifier) {
-
     var variableName = t.getSpecifierName(specifier);
 
-    if (specifier.default) {
-      specifier.id = DEFAULT_IDENTIFIER;
-    }
-
     var right = SETTER_MODULE_NAMESPACE;
     if (!t.isImportBatchSpecifier(specifier)) {
       right = t.memberExpression(right, specifier.id);
     }
-    systemTransform.importedVariables[variableName.name] = true;
-    systemTransform._addImportStatement(node.source.value, t.expressionStatement(
+    self.importedVariables[variableName.name] = true;
+    self._addImportStatement(node.source.value, t.expressionStatement(
       t.assignmentExpression("=", variableName, right)
     ));
 
@@ -124,16 +106,14 @@ SystemFormatter.prototype._extractImportSpecifiers = function (node) {
 };
 
 SystemFormatter.prototype._extractImport = function (node) {
-  if (!(t.isImportDeclaration(node))) {
+  if (!t.isImportDeclaration(node)) {
     return false;
   }
 
   this._addImportStatement(node.source.value);
 };
 
-//
 // Export extraction
-//
 
 SystemFormatter.prototype._extractExportDefault = function (node) {
   if (!(t.isExportDeclaration(node) && node.default)) {
@@ -141,7 +121,6 @@ SystemFormatter.prototype._extractExportDefault = function (node) {
   }
 
   var declar = node.declaration;
-  var variableName = DEFAULT_IDENTIFIER.name;
   var returnNode;
 
   if (t.isFunction(declar)) {
@@ -152,14 +131,14 @@ SystemFormatter.prototype._extractExportDefault = function (node) {
     declar = declar.id;
   }
 
-  this._addToExportStatements(variableName, declar);
+  this._addToExportStatements("default", declar);
 
   return returnNode;
 };
 
 SystemFormatter.prototype._extractExportVariableDeclaration = function (node) {
-  var systemTransform = this;
-  var declar          = node.declaration;
+  var self   = this;
+  var declar = node.declaration;
 
   if (!(t.isExportDeclaration(node) && t.isVariableDeclaration(declar))) {
     return false;
@@ -167,7 +146,7 @@ SystemFormatter.prototype._extractExportVariableDeclaration = function (node) {
 
   function separateDeclarationAndInit(memo, varDeclar) {
     memo.varDeclaration.push(_.omit(varDeclar, "init"));
-    systemTransform._addToExportStatements(varDeclar.id.name, varDeclar);
+    self._addToExportStatements(varDeclar.id.name, t.assignmentExpression("=", varDeclar.id, varDeclar.init));
     return memo;
   }
 
@@ -192,24 +171,22 @@ SystemFormatter.prototype._extractExportFunctionDeclaration = function (node) {
 };
 
 SystemFormatter.prototype._extractExportSpecifiers = function (node) {
-  var systemTransform = this;
+  var self = this;
 
-  if (!( t.isExportDeclaration(node) && node.specifiers )) {
+  if (!(t.isExportDeclaration(node) && node.specifiers)) {
     return false;
   }
 
   _.each(node.specifiers, function (specifier) {
-
     // Run each, break when one is true.
     _.some([
       SystemFormatter.prototype._extractExportBatch,
       SystemFormatter.prototype._extractExportFrom,
       SystemFormatter.prototype._extractExportNamed
     ], function (extractor) {
-      var result = extractor.call(systemTransform, specifier, node);
-      return result === void 0 || result;
+      var result = extractor.call(self, specifier, node);
+      return result === undefined || result;
     });
-
   });
 
   // Note: here we don't care about the node replacement.
@@ -218,7 +195,6 @@ SystemFormatter.prototype._extractExportSpecifiers = function (node) {
 };
 
 SystemFormatter.prototype._extractExportBatch = function (specifier, node) {
-
   if (!(node.source && t.isExportBatchSpecifier(specifier))) {
     return false;
   }
@@ -228,7 +204,6 @@ SystemFormatter.prototype._extractExportBatch = function (specifier, node) {
 };
 
 SystemFormatter.prototype._extractExportFrom = function (specifier, node) {
-
   // Weak test here...
   if (!(node.source)) {
     return false;
@@ -249,7 +224,6 @@ SystemFormatter.prototype._extractExportFrom = function (specifier, node) {
 };
 
 SystemFormatter.prototype._extractExportNamed = function (specifier) {
-
   // Last case...
   // Dunno what to test here...
 
@@ -257,9 +231,7 @@ SystemFormatter.prototype._extractExportNamed = function (specifier) {
   this._addToExportStatements(variableName.name, specifier.id);
 };
 
-//
 // Utils collection handler
-//
 
 SystemFormatter.prototype._addToExportStatements = function (name, identifier) {
   this.exportedStatements.push(
@@ -267,34 +239,21 @@ SystemFormatter.prototype._addToExportStatements = function (name, identifier) {
   );
 };
 
-/**
- * Generate a export wildcard expression
- * /!\ this is a hack over the existing "exports-wildcard" template
- * @param objectIdentifier
- * @returns the export wildcard expression
- * @private
- */
 SystemFormatter.prototype._makeExportWildcard = function (objectIdentifier) {
+  var leftIdentifier = t.identifier("i");
+  var valIdentifier  = t.memberExpression(objectIdentifier, leftIdentifier, true);
 
-  var exportStatement = util.template("exports-wildcard", {
-    OBJECT: objectIdentifier
-  }, true);
+  var left = t.variableDeclaration("var", [
+    t.variableDeclarator(leftIdentifier)
+  ]);
 
-  delete exportStatement.expression.callee.expression._scopeReferences;
+  var right = objectIdentifier;
 
-  var forStatement = exportStatement.expression.callee.expression.body.body[0];
-  var iteratorIdentifier = forStatement.left.declarations[0].id;
-  var target = t.memberExpression(
-    forStatement.right,
-    iteratorIdentifier,
-    true
-  );
+  var block = t.blockStatement([
+    this._makeExportStatements([leftIdentifier, valIdentifier])
+  ]);
 
-  forStatement.body.body = [
-    this._makeExportStatements([iteratorIdentifier, target])
-  ];
-
-  return exportStatement;
+  return t.forInStatement(left, right, block);
 };
 
 SystemFormatter.prototype._addImportStatement = function (name, importStatement) {
@@ -302,16 +261,12 @@ SystemFormatter.prototype._addImportStatement = function (name, importStatement)
   importStatement && this.moduleDependencies[name].push(importStatement);
 };
 
-//
 // Additional body content
-//
 
 SystemFormatter.prototype._prependImportVariables = function (ast) {
-
   var declaredSetters = _(this.importedVariables).keys().map(function (name) {
-      return _.compose(t.variableDeclarator, t.identifier)(name);
-    }
-  ).value();
+    return _.compose(t.variableDeclarator, t.identifier)(name);
+  }).value();
 
   if (declaredSetters.length) {
     ast.program.body.splice(1, 0, t.variableDeclaration("var", declaredSetters));
@@ -344,7 +299,6 @@ SystemFormatter.prototype._buildSetters = function () {
 };
 
 SystemFormatter.prototype._appendModuleReturnStatement = function (ast) {
-
   // generate the execute function expression
   var executeFunctionExpression = t.functionExpression(
     null, [], t.blockStatement(this.exportedStatements)
@@ -370,7 +324,7 @@ SystemFormatter.prototype._wrapInSystemRegisterCallExpression = function (ast) {
     .keys(this.moduleDependencies)
     .map(t.literal);
 
-  var runner = util.template("register", {
+  var runner = util.template("system", {
     MODULE_NAME: this.moduleNameLiteral,
     MODULE_DEPENDENCIES: t.arrayExpression(moduleDependencyNames),
     MODULE_BODY: t.functionExpression(
@@ -378,7 +332,7 @@ SystemFormatter.prototype._wrapInSystemRegisterCallExpression = function (ast) {
       [this.exportIdentifier],
       t.blockStatement(body)
     )
-  });
+  }, true);
 
-  program.body = [t.expressionStatement(runner)];
+  program.body = [runner];
 };

test/fixtures/transformation/es6-modules-system/exports-default/expected.js

@@ -1,12 +1,14 @@
-System.register("actual", [], function (_export) {
+System.register("es6-modules-system/exports-default/expected", [], function (_export) {
   "use strict";
 
-  var __moduleName = "actual";
+  var __moduleName = "es6-modules-system/exports-default/expected";
 
   function _anonymous() {}
-  var _anonymous2;
+  function _anonymous2() {}
+
   function foo() {}
-  var Foo;
+  function Foo() {}
+
   return {
     setters: [],
     execute: function () {
@@ -20,11 +22,11 @@ System.register("actual", [], function (_export) {
 
       _export("default", _anonymous);
 
-      _export("default", _anonymous2 = function _anonymous2() {});
+      _export("default", _anonymous2);
 
       _export("default", foo);
 
-      _export("default", Foo = function Foo() {});
+      _export("default", Foo);
     }
   };
 });

test/fixtures/transformation/es6-modules-system/exports-from/expected.js

@@ -1,15 +1,13 @@
-System.register("actual", ["foo"], function (_export) {
+System.register("es6-modules-system/exports-from/expected", ["foo"], function (_export) {
   "use strict";
 
-  var __moduleName = "actual";
+  var __moduleName = "es6-modules-system/exports-from/expected";
 
   return {
     setters: [function (m) {
-      (function (obj) {
-        for (var i in obj) {
-          _export(i, obj[i]);
-        }
-      })(m);
+      for (var i in m) {
+        _export(i, m[i]);
+      }
 
       _export("foo", m.foo);
 

test/fixtures/transformation/es6-modules-system/exports-named/expected.js

@@ -1,7 +1,7 @@
-System.register("actual", [], function (_export) {
+System.register("es6-modules-system/exports-named/expected", [], function (_export) {
   "use strict";
 
-  var __moduleName = "actual";
+  var __moduleName = "es6-modules-system/exports-named/expected";
 
   return {
     setters: [],

test/fixtures/transformation/es6-modules-system/exports-variable/expected.js

@@ -1,7 +1,7 @@
-System.register("actual", [], function (_export) {
+System.register("es6-modules-system/exports-variable/expected", [], function (_export) {
   "use strict";
 
-  var __moduleName = "actual";
+  var __moduleName = "es6-modules-system/exports-variable/expected";
 
   var foo;
   var foo2;
@@ -10,8 +10,6 @@ System.register("actual", [], function (_export) {
   var foo5;
   var foo6;
   function foo7() {}
-  _export("foo7", foo7);
-
   var foo8;
   return {
     setters: [],
@@ -20,11 +18,11 @@ System.register("actual", [], function (_export) {
 
       _export("foo2", foo2 = function () {});
 
-      _export("foo3", foo3);
+      _export("foo3", foo3 = undefined);
 
       _export("foo4", foo4 = 2);
 
-      _export("foo5", foo5);
+      _export("foo5", foo5 = undefined);
 
       _export("foo6", foo6 = 3);
 

test/fixtures/transformation/es6-modules-system/hoist-function-exports/expected.js

@@ -1,13 +1,12 @@
-System.register("actual", ["./evens"], function (_export) {
+System.register("es6-modules-system/hoist-function-exports/expected", ["./evens"], function (_export) {
   "use strict";
 
-  var __moduleName = "actual";
+  var __moduleName = "es6-modules-system/hoist-function-exports/expected";
 
   var isEven;
   function nextOdd(n) {
     return isEven(n) ? n + 1 : n + 2;
   }
-  _export("nextOdd", nextOdd);
 
   var isOdd;
   return {
@@ -15,6 +14,8 @@ System.register("actual", ["./evens"], function (_export) {
       isEven = m.isEven;
     }],
     execute: function () {
+      _export("nextOdd", nextOdd);
+
       _export("isOdd", isOdd = (function (isEven) {
         return function (n) {
           return !isEven(n);

test/fixtures/transformation/es6-modules-system/imports-default/expected.js

@@ -1,7 +1,7 @@
-System.register("actual", ["foo"], function (_export) {
+System.register("es6-modules-system/imports-default/expected", ["foo"], function (_export) {
   "use strict";
 
-  var __moduleName = "actual";
+  var __moduleName = "es6-modules-system/imports-default/expected";
 
   var foo;
   return {

test/fixtures/transformation/es6-modules-system/imports-glob/expected.js

@@ -1,7 +1,7 @@
-System.register("actual", ["foo"], function (_export) {
+System.register("es6-modules-system/imports-glob/expected", ["foo"], function (_export) {
   "use strict";
 
-  var __moduleName = "actual";
+  var __moduleName = "es6-modules-system/imports-glob/expected";
 
   var foo;
   return {

test/fixtures/transformation/es6-modules-system/imports-mixing/expected.js

@@ -1,7 +1,7 @@
-System.register("actual", ["foo"], function (_export) {
+System.register("es6-modules-system/imports-mixing/expected", ["foo"], function (_export) {
   "use strict";
 
-  var __moduleName = "actual";
+  var __moduleName = "es6-modules-system/imports-mixing/expected";
 
   var foo, xyz;
   return {

test/fixtures/transformation/es6-modules-system/imports-named/expected.js

@@ -1,7 +1,7 @@
-System.register("actual", ["foo"], function (_export) {
+System.register("es6-modules-system/imports-named/expected", ["foo"], function (_export) {
   "use strict";
 
-  var __moduleName = "actual";
+  var __moduleName = "es6-modules-system/imports-named/expected";
 
   var bar, baz, xyz;
   return {

test/fixtures/transformation/es6-modules-system/imports/expected.js

@@ -1,7 +1,7 @@
-System.register("actual", ["foo", "foo-bar", "./directory/foo-bar"], function (_export) {
+System.register("es6-modules-system/imports/expected", ["foo", "foo-bar", "./directory/foo-bar"], function (_export) {
   "use strict";
 
-  var __moduleName = "actual";
+  var __moduleName = "es6-modules-system/imports/expected";
 
   return {
     setters: [null, null, null],

test/fixtures/transformation/es6-modules-system/overview/expected.js

@@ -1,7 +1,7 @@
-System.register("actual", ["foo", "foo-bar", "./directory/foo-bar"], function (_export) {
+System.register("es6-modules-system/overview/expected", ["foo", "foo-bar", "./directory/foo-bar"], function (_export) {
   "use strict";
 
-  var __moduleName = "actual";
+  var __moduleName = "es6-modules-system/overview/expected";
 
   var foo, bar;
   var test;