add resolveModuleSource option - closes #471

lib/6to5/file.js

@@ -74,6 +74,7 @@ File.validOptions = [
   "format",
   "playground",
   "experimental",
+  "resolveModuleSource",
 
   // these are used by plugins
   "ignore",
@@ -92,6 +93,7 @@ File.normaliseOptions = function (opts) {
 
   defaults(opts, {
     keepModuleIdExtensions: false,
+    resolveModuleSource:    null,
     experimental:           false,
     reactCompat:            false,
     playground:             false,
@@ -332,7 +334,11 @@ File.prototype.transform = function (ast) {
   this.ast = ast;
   this.lastStatements = t.getLastStatements(ast.program);
   this.scope = new Scope(ast.program, ast, null, this);
-  this.moduleFormatter = this.getModuleFormatter(this.opts.modules);
+
+  var modFormatter = this.moduleFormatter = this.getModuleFormatter(this.opts.modules);
+  if (modFormatter.init && this.transformers["es6.modules"].canRun()) {
+    modFormatter.init();
+  }
 
   var astRun = function (key) {
     each(self.transformerStack, function (pass) {

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

@@ -15,6 +15,8 @@ function AMDFormatter() {
 
 util.inherits(AMDFormatter, DefaultFormatter);
 
+AMDFormatter.prototype.init = CommonFormatter.prototype.init;
+
 AMDFormatter.prototype.buildDependencyLiterals = function () {
   var names = [];
   for (var name in this.ids) {

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

@@ -9,14 +9,16 @@ var contains         = require("lodash/collection/contains");
 
 function CommonJSFormatter(file) {
   DefaultFormatter.apply(this, arguments);
-
-  if (this.hasNonDefaultExports) {
-    file.ast.program.body.push(util.template("exports-module-declaration", true));
-  }
 }
 
 util.inherits(CommonJSFormatter, DefaultFormatter);
 
+CommonJSFormatter.prototype.init = function () {
+  if (this.hasNonDefaultExports) {
+    this.file.ast.program.body.push(util.template("exports-module-declaration", true));
+  }
+};
+
 CommonJSFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
   var variableName = t.getSpecifierName(specifier);
 

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

@@ -21,6 +21,8 @@ function SystemFormatter(file) {
 
 util.inherits(SystemFormatter, AMDFormatter);
 
+SystemFormatter.prototype.init = function () {};
+
 SystemFormatter.prototype._addImportSource = function (node, exportNode) {
   node._importSource = exportNode.source && exportNode.source.value;
   return node;

lib/6to5/transformation/transformers/index.js

@@ -13,7 +13,7 @@ module.exports = {
 
   react:                                   require("./other/react"),
 
-  _modulesSplit:                           require("./internal/modules-split"),
+  _modules:                                require("./internal/modules"),
 
   // needs to be before `regenerator` due to generator comprehensions
   // needs to be before `_aliasFunction`

lib/6to5/transformation/transformers/internal/modules.js

@@ -8,7 +8,18 @@
 
 var t = require("../../../types");
 
+var resolveModuleSource = function (node, parent, scope, context, file) {
+  var resolveModuleSource = file.opts.resolveModuleSource;
+  if (node.source && resolveModuleSource) {
+    node.source.value = resolveModuleSource(node.source.value);
+  }
+};
+
+exports.ImportDeclaration = resolveModuleSource;
+
 exports.ExportDeclaration = function (node, parent, scope) {
+  resolveModuleSource.apply(null, arguments);
+
   var declar = node.declaration;
 
   if (node.default) {

test/fixtures/transformation/api/resolve-module-source/actual.js

@@ -0,0 +1,3 @@
+export { foo } from "foo-export-named";
+import foo from "foo-import-default";
+import "foo-import-bare";

test/fixtures/transformation/api/resolve-module-source/expected.js

@@ -0,0 +1,5 @@
+"use strict";
+
+export { foo } from "resolved/foo-export-named";
+import foo from "resolved/foo-import-default";
+import "resolved/foo-import-bare";

test/fixtures/transformation/api/resolve-module-source/options.js

@@ -0,0 +1,5 @@
+exports.blacklist = ["es6.modules"];
+
+exports.resolveModuleSource = function (originalSource) {
+  return "resolved/" + originalSource;
+};