feat(build): Allow building in windows without admin priviledges

Closes #2873

DEVELOPER.md

@@ -181,6 +181,9 @@ Karma is run against the new output.
 much easier to debug. `xit` and `xdescribe` can also be useful to exclude a test and a group of
 tests respectively.
 
+**Note**: **watch mode** needs symlinks to work, so if you're using windows, ensure you have the
+rights to built them in your operating system.
+
 ### E2E tests
 
 1. `$(npm bin)/gulp build.js.cjs` (builds benchpress and tests into `dist/js/cjs` folder).

tools/broccoli/broccoli-replace.ts

@@ -41,7 +41,11 @@ class DiffingReplace implements DiffingBroccoliPlugin {
             });
             fs.writeFileSync(destFilePath, content, FILE_ENCODING);
           } else if (!fs.existsSync(destFilePath)) {
+            try {
               fs.symlinkSync(sourceFilePath, destFilePath);
+            } catch (e) {
+              fs.writeFileSync(destFilePath, fs.readFileSync(sourceFilePath));
+            }
           }
         });
 

tools/build/linknodemodules.js

@@ -15,12 +15,34 @@ module.exports = function(gulp, plugins, config) {
       var linkDir = path.join(nodeModulesDir, relativeFolder);
       if (!fs.existsSync(linkDir)) {
         console.log('creating link', linkDir, sourceDir);
+        try {
           fs.symlinkSync(sourceDir, linkDir, 'dir');
         }
+        catch(e) {
+          var sourceDir = path.join(config.dir, relativeFolder);
+          console.log('linking failed: trying to hard copy', linkDir, sourceDir);
+          copyRecursiveSync(sourceDir, linkDir);
+        }
+      }
     });
   };
 };
 
+function copyRecursiveSync (src, dest) {
+  if (fs.existsSync(src)) {
+    var stats = fs.statSync(src);
+    if (stats.isDirectory()) {
+      fs.mkdirSync(dest);
+      fs.readdirSync(src).forEach(function(childItemName) {
+        copyRecursiveSync(path.join(src, childItemName),
+                          path.join(dest, childItemName));
+      });
+    } else {
+      fs.writeFileSync(dest, fs.readFileSync(src));
+    }
+  }
+}
+
 function getSubdirs(rootDir) {
   return fs.readdirSync(rootDir).filter(function(file) {
     if (file[0] === '.') {