fix #626, add AMD module format and make it default

lib/src/compiler/compiler.dart

Index: lib/src/compiler/compiler.dart
diff --git a/lib/src/compiler/compiler.dart b/lib/src/compiler/compiler.dart
index 77d03f06001903d13721d8df95cad6b419dd1298..c4d41690c1c4207813d69ce28badcca2bd6a9b06 100644
--- a/lib/src/compiler/compiler.dart
+++ b/lib/src/compiler/compiler.dart
@@ -143,11 +143,14 @@ class ModuleCompiler {
   }
 }
 
-enum ModuleFormat { es6, legacy, node }
+enum ModuleFormat { es6, commonjs, requirejs, legacy }
 
 ModuleFormat parseModuleFormat(String s) => {
       'es6': ModuleFormat.es6,
-      'node': ModuleFormat.node,
+      'commonjs': ModuleFormat.commonjs,
+      'requirejs': ModuleFormat.requirejs,
+      // Deprecated:
+      'node': ModuleFormat.commonjs,
       'legacy': ModuleFormat.legacy
     }[s];
 
@@ -222,7 +225,7 @@ class CompilerOptions {
       this.emitMetadata: false,
       this.closure: false,
       this.destructureNamedParams: false,
-      this.moduleFormat: ModuleFormat.legacy,
+      this.moduleFormat: ModuleFormat.requirejs,
       this.hoistInstanceCreation: true,
       this.hoistSignatureTypes: false,
       this.nameTypeTests: true,
@@ -258,15 +261,21 @@ class CompilerOptions {
               'disable if using X-SourceMap header',
           defaultsTo: true,
           hide: true)
-      ..addOption('modules',
-          help: 'module pattern to emit',
-          allowed: ['es6', 'legacy', 'node'],
-          allowedHelp: {
-            'es6': 'es6 modules',
-            'legacy': 'a custom format used by dartdevc, similar to AMD',
-            'node': 'node.js modules (https://nodejs.org/api/modules.html)'
-          },
-          defaultsTo: 'legacy')
+    ..addOption('modules',
+        help: 'module pattern to emit',
+        allowed: [
+          'es6',
+          'commonjs',
+          'requirejs',
+          /*deprecated*/ 'legacy',
+          /*renamed to commonjs*/ 'node'
+        ],
+        allowedHelp: {
+          'es6': 'es6 modules',
+          'commonjs': 'commonjs/node.js modules',
+          'requirejs': 'requirejs/amd modules'

[nweiz, 2016/08/16 22:14:53]

Nit: add capitalization to the help strings here.

[Jennifer Messerly, 2016/08/24 22:39:51]

Done.

+        },
+        defaultsTo: 'requirejs')

[vsm, 2016/08/16 21:23:23]

We should keep the default until we fix downstream uses (which probably don't
set this explicitly right now).

[Jennifer Messerly, 2016/08/16 21:29:27]

it's really easy to tweak our internal build rules, if that's what you're
worried about. We can set the formal explicitly long before this flows in.

[Jennifer Messerly, 2016/08/16 21:34:45]

I just sent you a CL that pins internal build rules to --modules=legacy

[Jennifer Messerly, 2016/08/24 22:39:51]

update: and this was landed.

       ..addFlag('emit-metadata',
           help: 'emit metadata annotations queriable via mirrors',
           defaultsTo: false)