remap UpdateExpression in module exports - closes #334

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

@@ -44,16 +44,42 @@ DefaultFormatter.prototype.remapAssignments = function () {
   var self = this;
 
   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);
+    var name = node.name;
+    return t.isIdentifier(node) && 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.isUpdateExpression(node) && isLocalReference(node.argument, scope)) {
+        this.stop();
 
-      if (t.isAssignmentExpression(node) && isLocalReference(node, scope)) {
+        // expand to long file assignment expression
+        var assign = t.assignmentExpression(node.operator[0] + "=", node.argument, t.literal(1));
+
+        // remap this assignment expression
+        var remapped = self.remapExportAssignment(assign);
+
+        // we don't need to change the result
+        if (t.isExpressionStatement(parent) || node.prefix) {
+          return remapped;
+        }
+
+        var nodes = [];
+        nodes.push(remapped);
+
+        var operator;
+        if (node.operator === "--") {
+          operator = "+";
+        } else { // "++"
+          operator = "-";
+        }
+        nodes.push(t.binaryExpression(operator, node.argument, t.literal(1)));
+
+        return t.sequenceExpression(nodes);
+      }
+
+      if (t.isAssignmentExpression(node) && isLocalReference(node.left, scope)) {
+        this.stop();
         return self.remapExportAssignment(node);
       }
     }

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

@@ -6,7 +6,7 @@ var t                = require("../../types");
 var _                = require("lodash");
 
 function AMDFormatter(file) {
-  this.file = file;
+  DefaultFormatter.apply(this, arguments);
   this.ids  = {};
 }
 

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

@@ -7,10 +7,11 @@ var t                = require("../../types");
 var _                = require("lodash");
 
 function SystemFormatter(file) {
+  this.exportIdentifier  = file.generateUidIdentifier("export");
+
   AMDFormatter.apply(this, arguments);
 
   this.moduleNameLiteral = t.literal(this.getModuleName());
-  this.exportIdentifier  = file.generateUidIdentifier("export");
 }
 
 util.inherits(SystemFormatter, AMDFormatter);

lib/6to5/traverse/index.js

@@ -50,17 +50,25 @@ function traverse(parent, opts, scope) {
         }
       };
 
+      var stop = false;
+
+      var context = {
+        stop: function () {
+          stop = true;
+        }
+      };
+
       //
       var ourScope = scope;
       if (t.isScope(node)) ourScope = new Scope(node, scope);
 
       // enter
       if (opts.enter) {
-        var result = opts.enter(node, parent, ourScope);
+        var result = opts.enter.call(context, node, parent, ourScope);
         maybeReplace(result);
 
         // stop iteration
-        if (result === false) return;
+        if (stop || result === false) return;
       }
 
       // traverse node
@@ -68,7 +76,7 @@ function traverse(parent, opts, scope) {
 
       // exit
       if (opts.exit) {
-        maybeReplace(opts.exit(node, parent, ourScope));
+        maybeReplace(opts.exit.call(context, node, parent, ourScope));
       }
     };
 
@@ -89,7 +97,6 @@ traverse.removeProperties = function (tree) {
     delete node._declarations;
     delete node.extendedRange;
     delete node._scopeInfo;
-    delete node._scope;
     delete node.tokens;
     delete node.range;
     delete node.start;

lib/6to5/types/index.js

@@ -240,14 +240,17 @@ t.getIds = function (node, map, ignoreTypes) {
     if (_.contains(ignoreTypes, id.type)) continue;
 
     var nodeKey = t.getIds.nodes[id.type];
-    var arrKey  = t.getIds.arrays[id.type];
+    var arrKeys  = t.getIds.arrays[id.type];
 
     if (t.isIdentifier(id)) {
       ids[id.name] = id;
     } else if (nodeKey) {
       if (id[nodeKey]) search.push(id[nodeKey]);
-    } else if (arrKey) {
-      search = search.concat(id[arrKey] || []);
+    } else if (arrKeys) {
+      for (var i in arrKeys) {
+        var key = arrKeys[i];
+        search = search.concat(id[key] || []);
+      }
     }
   }
 
@@ -268,11 +271,11 @@ t.getIds.nodes = {
 };
 
 t.getIds.arrays = {
-  ExportDeclaration: "specifiers",
-  ImportDeclaration: "specifiers",
-  VariableDeclaration: "declarations",
-  ArrayPattern: "elements",
-  ObjectPattern: "properties"
+  ExportDeclaration: ["specifiers", "declaration"],
+  ImportDeclaration: ["specifiers"],
+  VariableDeclaration: ["declarations"],
+  ArrayPattern: ["elements"],
+  ObjectPattern: ["properties"]
 };
 
 t.isLet = function (node) {

test/fixtures/transformation/es6-modules-amd/remap/actual.js

@@ -1,7 +1,9 @@
 export var test = 2;
 test = 5;
+test++;
 
 (function () {
   var test = 2;
   test = 3;
+  test++;
 })();

test/fixtures/transformation/es6-modules-amd/remap/expected.js

@@ -2,10 +2,12 @@ define(["exports"], function (exports) {
   "use strict";
 
   var test = exports.test = 2;
-  test = 5;
+  test = exports.test = 5;
+  test = exports.test += 1;
 
   (function () {
     var test = 2;
     test = 3;
+    test++;
   })();
 });

test/fixtures/transformation/es6-modules-common/remap/actual.js

@@ -1,7 +1,9 @@
 export var test = 2;
 test = 5;
+test++;
 
 (function () {
   var test = 2;
   test = 3;
+  test++;
 })();

test/fixtures/transformation/es6-modules-common/remap/expected.js

@@ -2,8 +2,10 @@
 
 var test = exports.test = 2;
 test = exports.test = 5;
+test = exports.test += 1;
 
 (function () {
   var test = 2;
   test = 3;
+  test++;
 })();

test/fixtures/transformation/es6-modules-ignore/remap/actual.js

@@ -1,7 +1,9 @@
 export var test = 2;
 test = 5;
+test++;
 
 (function () {
   var test = 2;
   test = 3;
+  test++;
 })();

test/fixtures/transformation/es6-modules-ignore/remap/expected.js

@@ -2,8 +2,10 @@
 
 var test = 2;
 test = 5;
+test++;
 
 (function () {
   var test = 2;
   test = 3;
+  test++;
 })();

test/fixtures/transformation/es6-modules-system/remap/actual.js

@@ -1,7 +1,9 @@
 export var test = 2;
 test = 5;
+test++;
 
 (function () {
   var test = 2;
   test = 3;
+  test++;
 })();

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

@@ -5,12 +5,14 @@ System.register("es6-modules-system/remap/expected", [], function (_export) {
       "use strict";
 
       var test = _export("test", 2);
-      test = 5;
+      _export("test", test = 5);
+      _export("test", test += 1);
 
       (function () {
         var test = 2;
         test = 3;
+        test++;
       })();
     }
   };
-});
+});

test/fixtures/transformation/es6-modules-umd/remap/actual.js

@@ -1,7 +1,9 @@
 export var test = 2;
 test = 5;
+test++;
 
 (function () {
   var test = 2;
   test = 3;
+  test++;
 })();

test/fixtures/transformation/es6-modules-umd/remap/expected.js

@@ -8,10 +8,12 @@
   "use strict";
 
   var test = exports.test = 2;
-  test = 5;
+  test = exports.test = 5;
+  test = exports.test += 1;
 
   (function () {
     var test = 2;
     test = 3;
+    test++;
   })();
 });