sfx optimization via rollup first attempt

lib/builder.js

@@ -12,6 +12,7 @@ exports.getCanonicalName = getCanonicalName;
 
 var attachCompilers = require('./compile').attachCompilers;
 var compileOutputs = require('./compile').compileOutputs;
+var wrapSFXOutputs = require('./compile').wrapSFXOutputs;
 var writeOutputs = require('./output').writeOutputs;
 
 var traceExpression = require('./arithmetic').traceExpression;
@@ -280,15 +281,27 @@ Builder.prototype.buildSFX = function(expression, outFile, opts) {
     opts.runtime = true;
 
   opts = processOpts(opts, outFile);
-  var tree;
 
   if (opts.config)
     this.config(opts.config);
 
+  // trace tree and entry points
+  var tree, entryPoints;
+
   return traceExpression(this, expression, true)
   .then(function(trace) {
     tree = trace.tree;
-    return compileOutputs(loader, tree, opts, trace.entryPoints);
+    entryPoints = trace.entryPoints;
+
+    // attempt optimization for all ES6
+    return require('./sfx-optimize').optimizeSFXTree(trace.tree, trace.entryPoints, opts);
+  })
+  .then(function(optimizedOutputs) {
+    // was all ES6, has already been compiled separately
+    if (optimizedOutputs)
+      return optimizedOutputs;
+
+    return compileOutputs(loader, tree, opts, entryPoints);
   })
   .then(function(outputs) {
     return writeOutputs(opts, outputs, loader.baseURL);

lib/sfx-optimize.js

@@ -0,0 +1,55 @@
+var rollup = require('rollup');
+var fromFileURL = require('./utils').fromFileURL;
+var toFileURL = require('./utils').toFileURL;
+
+function getLoad(tree, path) {
+  var address = toFileURL(path);
+  var load;
+  Object.keys(tree).some(function(name) {
+    if (tree[name].address == address || tree[name].name == path) {
+      load = tree[name];
+      return true;
+    }
+  });
+  return load;
+}
+
+exports.optimizeSFXTree = function(tree, entryPoints, opts) {
+  var allES = !Object.keys(tree).some(function(name) {
+    return tree[name].metadata.format !== 'esm';
+  });
+
+  if (!allES || entryPoints.length > 1)
+    return;
+
+  var entryName = entryPoints[0]
+
+  // whole tree is ES, we can use rollup to optimize for SFX!
+  return rollup.rollup({
+    entry: fromFileURL(tree[entryPoints[0]].address),
+    resolvePath: function(id, importer, options) {
+      return getLoad(tree, importer).depMap[id];
+    },
+    resolveExternal: function(id, importer, options) {
+      return getLoad(tree, importer).depMap[id];
+    },
+    load: function(path, options) {
+      return getLoad(tree, path).metadata.originalSource;
+    }
+  })
+  .then(function(bundle) {
+    var output = bundle.generate({
+      format: opts.sfxFormat === 'global' ? 'iife' : opts.sfxFormat,
+      exports: 'auto',
+
+      // we dont have this option in builder, as its assumed the user assigns to the global from within the ES6 module
+      // its probably worth introducing this option
+      moduleName: 'test'
+    });
+
+    return [{
+      source: output.code,
+      sourceMap: output.map
+    }];
+  });
+};

package.json

@@ -6,6 +6,7 @@
   "dependencies": {
     "glob": "^5.0.10",
     "mkdirp": "^0.5.1",
+    "rollup": "^0.8.1",
     "rsvp": "^3.0.18",
     "source-map": "^0.4.2",
     "systemjs": "^0.18.0",

test/fixtures/es-tree/a.js

@@ -0,0 +1,2 @@
+export {b} from './b.js';
+export var a = 'a';

test/fixtures/es-tree/b.js

@@ -0,0 +1 @@
+export var b = 'b';

test/static-optimize.js

@@ -0,0 +1,24 @@
+var Builder = require('../index');
+var builder = new Builder();
+
+var minify = false;
+
+builder.loadConfigSync('./test/fixtures/test-tree.config.js');
+
+builder.config({
+  transpiler: 'babel',
+  paths: {
+    '*': './test/fixtures/es-tree/*'
+  }
+});
+
+suite('SFX Optimizations', function() {
+  test('All ES6 rollup optimization', function(done) {
+    builder.buildSFX('a.js', 'test/output/es-sfx.js', { runtime: false, minify: minify })
+    .then(function(output) {
+      // TODO actually test
+      console.log(output);
+      done();
+    }, done)
+  });
+});

test/test-build.js

@@ -189,7 +189,8 @@ suite('Bundle Format', function() {
     })
     .then(function() {
       testPhantom('test/test-sfx-amd.html', done);
-    });
+    })
+    .catch(done);
   });
 });