chore(build): use a Filter plugin to write the dest folder.

This lets broccoli keep the dest folder up-to-date in 'watch' mode,
so we should be able to use that for Karma.

package.json

@@ -43,6 +43,7 @@
     "angular": "1.3.5",
     "bower": "^1.3.12",
     "broccoli": "^0.15.3",
+    "broccoli-filter": "^0.1.12",
     "broccoli-flatten": "^0.1.1",
     "broccoli-funnel": "igorminar/broccoli-funnel#perf-files",
     "broccoli-lodash": "^0.1.1",
@@ -52,7 +53,6 @@
     "broccoli-stew": "^0.2.1",
     "broccoli-writer": "^0.1.1",
     "canonical-path": "0.0.2",
-    "copy-dereference": "^1.0.0",
     "css": "mlaval/css#issue65",
     "del": "~1",
     "dgeni": "^0.4.1",
@@ -95,8 +95,8 @@
     "temp": "^0.8.1",
     "ternary-stream": "^1.2.3",
     "through2": "^0.6.1",
-    "typescript": "alexeagle/TypeScript#93dbbe2a2d0b42cefd02ac949e4bc8ab6b5b5823",
     "ts2dart": "^0.3.0",
+    "typescript": "alexeagle/TypeScript#93dbbe2a2d0b42cefd02ac949e4bc8ab6b5b5823",
     "vinyl": "^0.4.6",
     "walk-sync": "^0.1.3",
     "xtend": "^4.0.0",

tools/broccoli/broccoli-dest-copy.ts

@@ -0,0 +1,33 @@
+/// <reference path="./broccoli-filter.d.ts" />
+/// <reference path="../typings/node/node.d.ts" />
+/// <reference path="../typings/fs-extra/fs-extra.d.ts" />
+
+import Filter = require('broccoli-filter');
+import fse = require('fs-extra');
+import path = require('path');
+
+/**
+ * Intercepts each file as it is copied to the destination tempdir,
+ * and tees a copy to the given path outside the tmp dir.
+ */
+class DestCopy extends Filter {
+  constructor(private inputTree, private outputRoot: string) { super(inputTree); }
+
+  getDestFilePath(relativePath: string): string { return relativePath; }
+
+  processString(content: string, relativePath: string): string { return content; }
+
+  processFile(srcDir, destDir, relativePath): Promise<any> {
+    return super.processFile(srcDir, destDir, relativePath)
+        .then(x => {
+          var destFile = path.join(this.outputRoot, this.getDestFilePath(relativePath));
+          var dir = path.dirname(destFile);
+          fse.mkdirsSync(dir);
+          fse.copySync(path.join(srcDir, relativePath), destFile);
+        });
+  }
+}
+
+export = function destCopy(inputTree, outputRoot) {
+  return new DestCopy(inputTree, outputRoot);
+}

tools/broccoli/broccoli-filter.d.ts

@@ -0,0 +1,11 @@
+/// <reference path="../typings/es6-promise/es6-promise.d.ts" />
+
+
+declare class Filter {
+  constructor(inputTree: any);
+  processString(contents: string, relativePath: string): string;
+  // NB: This function is probably not intended as part of the public API
+  processFile(srcDir: string, destDir: string, relativePath: string): Promise<any>;
+}
+
+export = Filter;

tools/broccoli/gulp/index.ts

@@ -1,5 +1,5 @@
 var broccoli = require('broccoli');
-var copyDereferenceSync = require('copy-dereference').sync;
+var destCopy = require('../broccoli-dest-copy');
 var fse = require('fs-extra');
 var path = require('path');
 var printSlowTrees = require('broccoli-slow-trees');
@@ -26,31 +26,23 @@ function broccoliBuild(tree, outputRoot) {
   // We do a clean build every time to avoid stale outputs.
   // Broccoli's cache folders allow it to remain incremental without reading this dir.
   fse.removeSync(distPath);
-  fse.mkdirsSync(path.join(distPath, '..'));
+
+  tree = destCopy(tree, 'dist');
 
   var builder = new broccoli.Builder(tree);
   return builder.build()
-      .then(function(hash) {
-        console.log('=== Stats for %s (total: %ds) ===', outputRoot,
-                    Math.round(hash.totalTime / 1000000) / 1000);
-        printSlowTrees(hash.graph);
-
-        var dir = hash.directory;
-        try {
-          time('Write build output', function() {
-            copyDereferenceSync(path.join(dir, outputRoot), distPath);
-          });
-        } catch (err) {
-          if (err.code === 'EEXIST') err.message += ' (we cannot build into an existing directory)';
-          throw err;
-        }
-      })
-      .finally(function() {
-        time('Build cleanup', function() { builder.cleanup(); });
-
-        console.log('=== Done building %s ===', outputRoot);
-      })
-      .catch(function(err) {
+      .then(hash =>
+            {
+              console.log('=== Stats for %s (total: %ds) ===', outputRoot,
+                          Math.round(hash.totalTime / 1000000) / 1000);
+              printSlowTrees(hash.graph);
+            })
+      .finally(() =>
+               {
+                 time('Build cleanup', () => builder.cleanup());
+                 console.log('=== Done building %s ===', outputRoot);
+               })
+      .catch(err => {
         // Should show file and line/col if present
         if (err.file) {
           console.error('File: ' + err.file);

tools/broccoli/traceur/index.ts

@@ -37,7 +37,7 @@ class TraceurFilter extends Writer {
                 // TODO: we should fix the sourceMappingURL written by Traceur instead of overriding
                 // (but we might switch to typescript first)
                 var mapFilepath = filepath.replace(/\.\w+$/, '') + this.destSourceMapExtension;
-                result.js = result.js + '\n  //# sourceMappingURL=./' + path.basename(mapFilepath);
+                result.js = result.js + '\n//# sourceMappingURL=./' + path.basename(mapFilepath);
 
                 var destFilepath = filepath.replace(/\.\w+$/, this.destExtension);
                 var destFile = path.join(destDir, destFilepath);