es6-module-transpiler - npm Package Compare versions

Comparing version 0.8.3 to 0.9.0

lib/formatters/bundle_formatter.js

@@ -61,2 +61,13 @@ /* jshint node:true, undef:true, unused:true */
   container.findImportedModules();
+
+  // Cache all the import and export specifier names.
+  container.getModules().forEach(function(mod) {
+    [mod.imports, mod.exports].forEach(function(bindingList) {
+      bindingList.declarations.forEach(function (declaration) {
+        declaration.specifiers.forEach(function (specifier) {
+          specifier.name;
+        });
+      });
+    });
+  });
 };
@@ -71,2 +82,3 @@
     b.expressionStatement(b.literal('use strict')),
+      this.buildNamespaceImportObjects(modules),
       modules.length === 1 ?
@@ -81,2 +93,95 @@ modules[0].ast.program.body :
 /**
+ * Builds a variable declaration that contains declarations of all the namespace
+ * objects required by `import * as foo from 'foo'` statements.
+ *
+ * @private
+ * @param {Module[]} modules
+ * @return {?AST.VariableDeclaration}
+ */
+BundleFormatter.prototype.buildNamespaceImportObjects = function(modules) {
+  var self = this;
+  var namespaceImportedModules = [];
+
+  // Collect all the modules imported using a namespace import declaration.
+  modules.forEach(function(mod) {
+    mod.imports.namespaceImports.forEach(function(namespaceImportDeclaration) {
+      var namespaceImportedModule = namespaceImportDeclaration.source;
+      if (namespaceImportedModules.indexOf(namespaceImportedModule) < 0) {
+        namespaceImportedModules.push(namespaceImportedModule);
+      }
+    });
+  });
+
+  if (namespaceImportedModules.length === 0) {
+    return null;
+  }
+
+  /**
+   * Builds a variable declarator for the given module whose initial value is an
+   * object with properties for each export from the module being imported. For
+   * example, given a module "foo" with exports "a" and "b" this object will be
+   * created:
+   *
+   *   foo$$ = {
+   *     get a() {
+   *       return foo$$a;
+   *     },
+   *
+   *     get b() {
+   *       return foo$$b;
+   *     }
+   *   }
+   *
+   * @param {Module} mod
+   * @returns {AST.VariableDeclarator}
+   */
+  function createDeclaratorForModule(mod) {
+    return b.variableDeclarator(
+      b.identifier(mod.id),
+      b.objectExpression(
+        mod.exports.declarations.reduce(function(props, exportDeclaration) {
+          exportDeclaration.specifiers.forEach(function(specifier) {
+            props.push(createGetterForSpecifier(mod, specifier));
+          });
+
+          return props;
+        }, [])
+      )
+    );
+  }
+
+  /**
+   * Builds a getter property for retrieving the value of the given export
+   * specifier at the time it is accessed. For example, given a module "foo"
+   * with export specifier "a" this property will be created:
+   *
+   *   get a() {
+   *     return foo$$a;
+   *   }
+   *
+   * @param {Module} mod
+   * @param {ExportSpecifier} specifier
+   * @returns {AST.Property}
+   */
+  function createGetterForSpecifier(mod, specifier) {
+    return b.property(
+      'get',
+      b.identifier(specifier.name),
+      b.functionExpression(
+        null,
+        [],
+        b.blockStatement([
+          b.returnStatement(self.reference(mod, specifier.name))
+        ])
+      )
+    );
+  }
+
+  return b.variableDeclaration(
+    'var',
+    namespaceImportedModules.map(createDeclaratorForModule)
+  );
+};
+
+/**
  * @override
@@ -183,7 +288,12 @@ *
   var specifier = mod.imports.findSpecifierForReference(referencePath);
-  if (specifier) {
+
+  if (!specifier) {
+    return null;
+  }
+
+  if (specifier.from) {
     specifier = specifier.terminalExportSpecifier;
     return this.reference(specifier.module, specifier.name);
   } else {
-    return null;
+    return b.identifier(specifier.declaration.source.id);
   }
@@ -190,0 +300,0 @@ };

lib/formatters/commonjs_formatter.js

@@ -13,3 +13,2 @@ /* jshint node:true, undef:true, unused:true */
 var Formatter = require('./formatter');
-var sourcePosition = require('../utils').sourcePosition;
 
@@ -37,10 +36,21 @@ /**
     var body = mod.ast.program.body;
-    body.unshift(
-      b.expressionStatement(b.literal('use strict')),
-      self.buildEarlyExports(mod),
-      self.buildRequires(mod)
-    );
-    body.push(
-      self.buildLateExports(mod)
-    );
+
+    var requiresDeclaration = self.buildRequires(mod);
+    var earlyExportsStatement = self.buildEarlyExports(mod);
+    var lateExports = self.buildLateExports(mod);
+
+    if (requiresDeclaration) {
+      body.unshift(requiresDeclaration);
+    }
+
+    if (earlyExportsStatement) {
+      body.unshift(earlyExportsStatement);
+    }
+
+    body.unshift(b.expressionStatement(b.literal('use strict')));
+
+    if (lateExports) {
+      body.push(lateExports);
+    }
+
     mod.ast.filename = mod.relativePath;
@@ -56,7 +66,6 @@ return mod.ast;
  * @param {Module} mod
- * @returns {AST.Statement}
+ * @returns {?AST.Statement}
  * @private
  */
 CommonJSFormatter.prototype.buildEarlyExports = function(mod) {
-  var self = this;
   var assignments = [];
@@ -82,5 +91,9 @@ var exportObject = b.identifier('exports');
 
-  return b.expressionStatement(
-    b.sequenceExpression(assignments)
-  );
+  if (assignments.length > 0) {
+    return b.expressionStatement(
+      b.sequenceExpression(assignments)
+    );
+  } else {
+    return null;
+  }
 };
@@ -93,3 +106,3 @@
  * @param {Module} mod
- * @returns {AST.Statement}
+ * @returns {?AST.Statement}
  * @private
@@ -132,5 +145,9 @@ */
 
-  return b.expressionStatement(
-    b.sequenceExpression(assignments)
-  );
+  if (assignments.length > 0) {
+    return b.expressionStatement(
+      b.sequenceExpression(assignments)
+    );
+  } else {
+    return null;
+  }
 };
@@ -170,3 +187,3 @@
  * @param {Module} mod
- * @return {AST.VariableDeclaration|AST.EmptyStatement}
+ * @return {?AST.VariableDeclaration}
  */
@@ -211,3 +228,3 @@ CommonJSFormatter.prototype.buildRequires = function(mod) {
   } else {
-    return b.emptyStatement();
+    return null;
   }
@@ -302,3 +319,9 @@ };
 
-  if (specifier) {
+  if (!specifier) {
+    return null;
+  }
+
+  if (specifier.from) {
+    // import { value } from './a';
+    // import a from './a';
     return this.reference(
@@ -309,3 +332,4 @@ specifier.declaration.source,
   } else {
-    return null;
+    // import * as a from './a'
+    return b.identifier(specifier.declaration.source.id);
   }
@@ -312,0 +336,0 @@ };

lib/imports.js

@@ -50,2 +50,15 @@ /* jshint node:true, undef:true, unused:true */
 /**
+ * Gets the namespace imports from the list of imports.
+ *
+ * @private
+ * @type {ImportDeclaration[]}
+ * @name ImportDeclaration#namespaceImports
+ */
+memo(ImportDeclarationList.prototype, 'namespaceImports', /** @this ImportDeclarationList */function() {
+  return this.declarations.filter(function(declaration) {
+    return declaration.hasNamespaceImport;
+  });
+});
+
+/**
  * Contains information about an import declaration.
@@ -85,13 +98,9 @@ *
   var self = this;
-  return this.node.specifiers.map(function(s) {
-    var specifier = new ImportSpecifier(self, s);
-    if (n.ImportDefaultSpecifier.check(s)) {
-      specifier.from = 'default';
-    } else if (n.ImportNamespaceSpecifier.check(s)) {
-      // TODO: implement import * as ...
-      specifier.from = '*';
-    } else {
-      specifier = new ImportSpecifier(self, s);
+  return this.node.specifiers.map(function(specifier) {
+    if (n.ImportDefaultSpecifier.check(specifier)) {
+      return new ImportDefaultSpecifier(self, specifier);
+    } else if (n.ImportNamespaceSpecifier.check(specifier)) {
+      return new ImportNamespaceSpecifier(self, specifier);
     }
-    return specifier;
+    return new ImportNamedSpecifier(self, specifier);
   });
@@ -101,2 +110,12 @@ });
 /**
+ * @type {boolean}
+ * @name ImportDeclaration#hasNamespaceImport
+ */
+memo(ImportDeclaration.prototype, 'hasNamespaceImport', /** @this ImportDeclaration */function() {
+  return this.specifiers.some(function(specifier) {
+    return specifier instanceof ImportNamespaceSpecifier;
+  });
+});
+
+/**
  * Represents an import specifier. The "a" and "b as c" are both import
@@ -110,5 +129,5 @@ * specifiers in the following import statement.
  * @param {ImportDeclaration} declaration
- * @param {AST.ImportSpecifier} node
+ * @param {AST.ImportNamedSpecifier} node
  */
-function ImportSpecifier(declaration, node) {
+function ImportNamedSpecifier(declaration, node) {
   assert.ok(
@@ -120,3 +139,3 @@ declaration instanceof ImportDeclaration,
 }
-extend(ImportSpecifier, ModuleBindingSpecifier);
+extend(ImportNamedSpecifier, ModuleBindingSpecifier);
 
@@ -127,3 +146,3 @@ /**
  */
-memo(ImportSpecifier.prototype, 'exportSpecifier', /** @this ImportSpecifier */function() {
+memo(ImportNamedSpecifier.prototype, 'exportSpecifier', /** @this ImportSpecifier */function() {
   var source = this.declaration.source;
@@ -141,2 +160,69 @@ assert.ok(source, 'import specifiers must have a valid source');
 
+
+/**
+ * Represents a default import specifier. The "a" in the following import statement.
+ *
+ *   import a from "a";
+ *
+ * @constructor
+ * @extends ModuleBindingSpecifier
+ * @param {ImportDeclaration} declaration
+ * @param {AST.ImportDefaultSpecifier} node
+ */
+function ImportDefaultSpecifier(declaration, node) {
+  assert.ok(
+    declaration instanceof ImportDeclaration,
+    'expected an instance of ImportDeclaration'
+  );
+  ModuleBindingSpecifier.call(this, declaration, node);
+}
+extend(ImportDefaultSpecifier, ModuleBindingSpecifier);
+
+memo(ImportDefaultSpecifier.prototype, 'exportSpecifier', /** @this ImportSpecifier */function() {
+  var source = this.declaration.source;
+  assert.ok(source, 'import specifiers must have a valid source');
+  var exportSpecifier = source.exports.findSpecifierByName(this.from);
+  assert.ok(
+    exportSpecifier,
+    'import `default` at ' +
+    sourcePosition(this.module, this.node) +
+    ' has no matching export in ' + source.relativePath
+  );
+  return exportSpecifier;
+});
+
+memo(ImportDefaultSpecifier.prototype, 'from', function() {
+  return 'default';
+});
+
+/**
+ * Represents a namespace import specifier. The "a" in the following import
+ * statement.
+ *
+ *   import * as a from "a";
+ *
+ * @constructor
+ * @extends ModuleBindingSpecifier
+ * @param {ImportDeclaration} declaration
+ * @param {AST.ImportNamespaceSpecifier} node
+ */
+function ImportNamespaceSpecifier(declaration, node) {
+  assert.ok(
+    declaration instanceof ImportDeclaration,
+    'expected an instance of ImportDeclaration'
+  );
+  ModuleBindingSpecifier.call(this, declaration, node);
+}
+extend(ImportNamespaceSpecifier, ModuleBindingSpecifier);
+
+memo(ImportNamespaceSpecifier.prototype, 'exportSpecifier', /** @this ImportSpecifier */function() {
+  var source = this.declaration.source;
+  assert.ok(source, 'import specifiers must have a valid source');
+  return null;
+});
+
+memo(ImportNamespaceSpecifier.prototype, 'from', function() {
+  return null;
+});
+
 module.exports = ImportDeclarationList;

lib/rewriter.js

@@ -258,29 +258,61 @@ /* jshint node:true, undef:true, unused:true */
  * @param {Module} mod
- * @param {Identifier} identifierPath
+ * @param {Identifier} nodePath
  */
-Rewriter.prototype.assertImportIsNotReassigned = function(mod, identifierPath) {
-  if (!n.Identifier.check(identifierPath.node) || !mod.imports.findDeclarationForReference(identifierPath)) {
+Rewriter.prototype.assertImportIsNotReassigned = function(mod, nodePath) {
+  var declarationPath;
+  var identifierPath;
+  var bindingDescription;
+
+  if (n.Identifier.check(nodePath.node)) {
+    // Do we have a named import…
+    //
+    //   import { foo } from 'foo';
+    //
+    // …that we then try to assign or update?
+    //
+    //   foo++;
+    //   foo = 1;
+    //
+    declarationPath = mod.imports.findDeclarationForReference(nodePath);
+    if (!declarationPath || !n.ImportSpecifier.check(declarationPath.parent.node)) {
+      return;
+    }
+
+    bindingDescription = '`' + declarationPath.node.name + '`';
+  } else if (n.MemberExpression.check(nodePath.node)) {
+    // Do we have a namespace import…
+    //
+    //   import * as foo from 'foo';
+    //
+    // …with a property that we then try to assign or update?
+    //
+    //   foo.a++;
+    //   foo.a = 1;
+    //   foo['a'] = 1;
+    //
+    var objectPath = nodePath.get('object');
+
+    if (!n.Identifier.check(objectPath.node)) {
+      return;
+    }
+
+    declarationPath = mod.imports.findDeclarationForReference(objectPath);
+    if (!declarationPath || !n.ImportNamespaceSpecifier.check(declarationPath.parent.node)) {
+      return;
+    }
+
+    var propertyPath = nodePath.get('property');
+    if (n.Identifier.check(propertyPath.node)) {
+      bindingDescription = '`' + propertyPath.node.name + '`';
+    } else {
+      bindingDescription = 'of namespace `' + objectPath.node.name + '`';
+    }
+  } else {
     return;
   }
 
-  var identifier = identifierPath.node;
-  var name = identifier.name;
-  var declarationScope = identifierPath.scope.lookup(name);
-  if (declarationScope && declarationScope.isGlobal) {
-    var declarationPaths = declarationScope.getBindings()[name];
-    assert.ok(
-      declarationPaths.length === 1,
-      'expected exactly one declaration for `' + name +
-      '`, found ' + declarationPaths.length
-    );
-    var declarationPath = declarationPaths[0];
-    if (n.ImportSpecifier.check(declarationPath.parent.node) ||
-        n.ImportDefaultSpecifier.check(declarationPath.parent.node) ||
-        n.ImportNamespaceSpecifier.check(declarationPath.parent.node)) {
-      throw new SyntaxError(
-        'Cannot reassign imported binding `' + name +
-        '` at ' + sourcePosition(mod, identifier)
-      );
-    }
-  }
+  throw new SyntaxError(
+    'Cannot reassign imported binding ' + bindingDescription +
+    ' at ' + sourcePosition(mod, nodePath.node)
+  );
 };
@@ -287,0 +319,0 @@

package.json

 {
   "name": "es6-module-transpiler",
-  "version": "0.8.3",
+  "version": "0.9.0",
   "description": "es6-module-transpiler is an experimental compiler that allows you to write your JavaScript using a subset of the current ES6 module syntax, and compile it into various formats.",
@@ -5,0 +5,0 @@ "homepage": "http://esnext.github.io/es6-module-transpiler",

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Improved metrics

Total package byte prevSize

114270

increased by6.27%

Lines of code

3506

increased by6.73%

No dependency changes