Fix for node modules

lib/src/compiler/module_builder.dart

Index: lib/src/compiler/module_builder.dart
diff --git a/lib/src/compiler/module_builder.dart b/lib/src/compiler/module_builder.dart
index 7a6866c6463c53269bc03c0f817ff11c01b59a5a..ec193d98abca6680a9dfde071e410b3b0282692c 100644
--- a/lib/src/compiler/module_builder.dart
+++ b/lib/src/compiler/module_builder.dart
@@ -104,7 +104,10 @@ class LegacyModuleBuilder extends _ModuleBuilder {
 /// Generates node modules.
 class NodeModuleBuilder extends _ModuleBuilder {
   Program build(Program module) {
-    var importStatements = [js.statement("'use strict';"),];
+    var importStatements = [];
+
+    // Collect imports/exports/statements.
+    visitProgram(module);
 
     for (var import in imports) {
       // TODO(jmesserly): we could use destructuring once Atom supports it.
@@ -135,7 +138,11 @@ class NodeModuleBuilder extends _ModuleBuilder {
         }
       }
     }
-    return new Program(statements);
+
+    var block =

[vsm, 2016/04/18 13:38:25]

Not entirely sure why I seem to need this.  Without it, it seems js_ast wasn't
renaming colliding identifiers.  I'd get redundant declarations in the SDK:

  const _add = Symbol('_add');
  ...
  const _add = Symbol('_add');

By nesting the whole thing, I'd see:

  const _add = Symbol('_add');
  ...
  const _add$ = Symbol('_add');

Is js_ast not renaming at the top-level?

[Jennifer Messerly, 2016/04/18 20:52:18]

Yeah seems like it's skipping the top-level. That's probably an easy fix though.

Do you mind taking a look? IMO, it'd be good to understand what's going on,
rather than work around it.

Could be a TODO as well. But it'd be nice to keep the technical debt low (I'm
still recovering from the last big cleanup ;)... not to mention our runtime/SDK
debt.)

[vsm, 2016/04/19 21:28:29]

Added a TODO and filed a bug for now.

+        js.statement("(function() { 'use strict'; #; })()", [statements]);
+
+    return new Program([block]);
   }
 }