fix incorrect interpreation of export default shorthand, update to new ast definitions - #1091

src/acorn/src/statement.js

@@ -560,12 +560,22 @@ pp.parseExport = function(node) {
   // export * from '...'
   if (this.eat(tt.star)) {
     if (this.options.features["es7.exportExtensions"] && this.eatContextual("as")) {
-      node.exported = this.parseIdent()
+      let specifier = this.startNode()
+      specifier.exported = this.parseIdent()
+      node.specifiers = [this.finishNode(specifier, "ExportNamespaceSpecifier")]
+      this.parseExportSpecifiersMaybe(node)
+      this.parseExportFrom(node)
+    } else {
+      this.parseExportFrom(node)
+      return this.finishNode(node, "ExportAllDeclaration")
     }
+  } else if (this.isExportDefaultSpecifier()) {
+    let specifier = this.startNode()
+    specifier.exported = this.parseIdent(true)
+    node.specifiers = [this.finishNode(specifier, "ExportDefaultSpecifier")]
+    this.parseExportSpecifiersMaybe(node)
     this.parseExportFrom(node)
-    return this.finishNode(node, "ExportAllDeclaration")
-  }
-  if (this.eat(tt._default)) { // export default ...
+  } else if (this.eat(tt._default)) { // export default ...
     let expr = this.parseMaybeAssign()
     let needsSemi = true
     if (expr.type == "FunctionExpression" ||
@@ -581,16 +591,10 @@ pp.parseExport = function(node) {
     if (needsSemi) this.semicolon()
     this.checkExport(node)
     return this.finishNode(node, "ExportDefaultDeclaration")
-  }
-  // export var|const|let|function|class ...
-  if (this.type.keyword || this.shouldParseExportDeclaration()) {
+  } else if (this.type.keyword || this.shouldParseExportDeclaration()) {
     node.declaration = this.parseStatement(true)
     node.specifiers = []
     node.source = null
-  } else if (this.type === tt.name) {
-    node.exported = this.parseIdent()
-    this.parseExportFrom(node)
-    return this.finishNode(node, "ExportNamespaceDeclaration")
   } else { // export { x, y as z } [from '...']
     node.declaration = null
     node.specifiers = this.parseExportSpecifiers()
@@ -605,6 +609,25 @@ pp.parseExport = function(node) {
   return this.finishNode(node, "ExportNamedDeclaration")
 }
 
+pp.isExportDefaultSpecifier = function () {
+  if (this.type === tt.name) {
+    return this.value !== "type" && this.value !== "async"
+  }
+
+  if (this.type !== tt._default) {
+    return false
+  }
+
+  var lookahead = this.lookahead()
+  return lookahead.type === tt.comma || (lookahead.type === tt.name && lookahead.value === "from")
+}
+
+pp.parseExportSpecifiersMaybe = function (node) {
+  if (this.eat(tt.comma)) {
+    node.specifiers = node.specifiers.concat(this.parseExportSpecifiers())
+  }
+}
+
 pp.parseExportFrom = function(node) {
   this.expectContextual("from")
   node.source = this.type === tt.string ? this.parseExprAtom() : this.unexpected()

src/babel/generation/generators/modules.js

@@ -13,6 +13,10 @@ export function ImportDefaultSpecifier(node, print) {
   print(node.local);
 }
 
+export function ExportDefaultSpecifier(node, print) {
+  print(node.exported);
+}
+
 export function ExportSpecifier(node, print) {
   print(node.local);
   if (node.exported && node.local !== node.exported) {
@@ -21,12 +25,9 @@ export function ExportSpecifier(node, print) {
   }
 }
 
-export function ExportNamespaceDeclaration(node, print) {
-  this.push("export ");
+export function ExportNamespaceSpecifier(node, print) {
+  this.push("* as ");
   print(node.exported);
-  this.push(" from ");
-  print(node.source);
-  this.semicolon();
 }
 
 export function ExportAllDeclaration(node, print) {
@@ -54,16 +55,29 @@ function ExportDeclaration(node, print) {
   var specifiers = node.specifiers;
 
   if (node.declaration) {
-    print(node.declaration);
-    if (t.isStatement(node.declaration)) return;
+    var declar = node.declaration;
+    print(declar);
+    if (t.isStatement(declar) || t.isFunction(declar) || t.isClass(declar)) return;
   } else {
-    this.push("{");
-    if (specifiers.length) {
-      this.space();
-      print.join(specifiers, { separator: ", " });
-      this.space();
+    var first = specifiers[0];
+    var hasSpecial = false;
+    if (t.isExportDefaultSpecifier(first) || t.isExportNamespaceSpecifier(first)) {
+      hasSpecial = true;
+      print(specifiers.shift());
+      if (specifiers.length) {
+        this.push(", ");
+      }
+    }
+
+    if (specifiers.length || (!specifiers.length && !hasSpecial)) {
+      this.push("{");
+      if (specifiers.length) {
+        this.space();
+        print.join(specifiers, { separator: ", " });
+        this.space();
+      }
+      this.push("}");
     }
-    this.push("}");
 
     if (node.source) {
       this.push(" from ");
@@ -83,25 +97,20 @@ export function ImportDeclaration(node, print) {
 
   var specfiers = node.specifiers;
   if (specfiers && specfiers.length) {
-    var foundImportSpecifier = false;
-
-    for (var i = 0; i < node.specifiers.length; i++) {
-      var spec = node.specifiers[i];
-
-      if (i > 0) {
+    var first = node.specifiers[0];
+    if (t.isImportDefaultSpecifier(first) || t.isImportNamespaceSpecifier(first)) {
+      print(node.specifiers.shift());
+      if (node.specifiers.length) {
         this.push(", ");
       }
-
-      if (!t.isImportDefaultSpecifier(spec) && !t.isImportNamespaceSpecifier(spec) && !foundImportSpecifier) {
-        foundImportSpecifier = true;
-        this.push("{ ");
-      }
-
-      print(spec);
     }
 
-    if (foundImportSpecifier) {
-      this.push(" }");
+    if (node.specifiers.length) {
+      this.push("{");
+      this.space()
+      print.join(node.specifiers, { separator: ", " });
+      this.space()
+      this.push("}");
     }
 
     this.push(" from ");

src/babel/transformation/modules/_default.js

@@ -62,7 +62,7 @@ var exportsVisitor = traverse.explode({
         extend(formatter.localExports, declar.getBindingIdentifiers());
       }
 
-      if (!t.isExportDefaultDeclaration(node) && !t.isExportNamespaceDeclaration(node)) {
+      if (!t.isExportDefaultDeclaration(node)) {
         formatter.hasNonDefaultExports = true;
       }
 

src/babel/transformation/transformers/es7/export-extensions.js

@@ -3,23 +3,33 @@
 import * as t from "../../../types";
 
 export function check(node) {
-  return t.isExportNamespaceDeclaration(node) || (t.isExportAllDeclaration(node) && node.exported);
+  return t.isExportDefaultSpecifier(node) || t.isExportNamespaceSpecifier(node);
 }
 
-export function ExportNamespaceDeclaration(node, parent, scope) {
-  var uid = scope.generateUidIdentifier("default");
-  return [
-    t.importDeclaration([t.importDefaultSpecifier(uid)], node.source),
-    t.exportDefaultDeclaration(uid)
-  ];
-}
+export function ExportNamedDeclaration(node, parent, scope) {
+  var nodes = [];
 
-export function ExportAllDeclaration(node, parent, scope) {
-  if (node.exported) {
-    var uid = scope.generateUidIdentifier(node.exported.name);
-    return [
+  if (t.isExportNamespaceSpecifier(node.specifiers[0])) {
+    var specifier = node.specifiers.shift();
+    var uid = scope.generateUidIdentifier(specifier.exported.name);
+    nodes.push(
       t.importDeclaration([t.importNamespaceSpecifier(uid)], node.source),
-      t.exportNamedDeclaration(null, [t.exportSpecifier(uid, node.exported)])
-    ];
+      t.exportNamedDeclaration(null, [t.exportSpecifier(uid, specifier.exported)])
+    );
+  } else if (t.isExportDefaultSpecifier(node.specifiers[0])) {
+    var specifier = node.specifiers.shift();
+    var uid = scope.generateUidIdentifier(specifier.exported.name);
+    nodes.push(
+      t.importDeclaration([t.importSpecifier(uid, specifier.exported)], node.source),
+      t.exportNamedDeclaration(null, [t.exportSpecifier(uid, specifier.exported)])
+    );
   }
+
+  if (!nodes.length) return;
+
+  if (node.specifiers.length > 1) {
+    nodes.push(node);
+  }
+
+  return nodes;
 }

src/babel/types/alias-keys.json

@@ -15,7 +15,9 @@
   "LabeledStatement":         ["Statement"],
   "VariableDeclaration":      ["Statement", "Declaration"],
 
-  "ExportNamespaceDeclaration": ["Statement", "Declaration", "ModuleDeclaration", "ExportDeclaration"],
+  "ExportDefaultSpecifier":     ["ModuleSpecifier"],
+  "ExportNamespaceSpecifier":   ["ModuleSpecifier"],
+  "ExportDefaultFromSpecifier": ["ModuleSpecifier"],
   "ExportAllDeclaration":       ["Statement", "Declaration", "ModuleDeclaration", "ExportDeclaration"],
   "ExportDefaultDeclaration":   ["Statement", "Declaration", "ModuleDeclaration", "ExportDeclaration"],
   "ExportNamedDeclaration":     ["Statement", "Declaration", "ModuleDeclaration", "ExportDeclaration"],

src/babel/types/visitor-keys.json

@@ -69,9 +69,10 @@
   "YieldExpression":           ["argument"],
 
   "ExportAllDeclaration":       ["source", "exported"],
-  "ExportNamespaceDeclaration": ["exported"],
   "ExportDefaultDeclaration":   ["declaration"],
   "ExportNamedDeclaration":     ["declaration", "specifiers", "source"],
+  "ExportDefaultSpecifier":     ["exported"],
+  "ExportNamespaceSpecifier":   ["exported"],
   "ExportSpecifier":            ["local", "exported"],
 
   "AnyTypeAnnotation":           [],