adding support for duo's cache

index.js

@@ -12,7 +12,6 @@ var path = require('path');
  * Helper methods.
  */
 
-var compile = babel.transform;
 var canCompile = babel.util.canCompile;
 
 /**
@@ -49,37 +48,75 @@ function plugin(o) {
   var ignore = extract(o, 'ignore');
   if (ignore) debug('not compiling files matching', ignore);
 
-  return function babel(file, entry) {
+  return function* babel(file, entry) {
     // compile only what babel recognizes
     if (!canCompile(file.path, extensions)) return debug('ignoring file: %s', file.path);
 
     // ignore remotes if configured to
     if (onlyLocals && file.remote()) return debug('ignoring remote: %s', file.id);
 
-    var root = file.duo.root();
-
-    var options = extend(true, {
-      filename: file.path,
-      filenameRelative: file.id,
-      sourceMap: file.duo.sourceMap() ? 'inline' : false,
-      sourceRoot: '/',
-      only: prepend(only, root),
-      ignore: prepend(ignore, root)
-    }, o);
-
-    try {
-      debug('attempting to compile: %s', file.id, options);
-      var es5 = compile(file.src, options);
-      if (file.src === es5.code) debug('did not compile: %s', file.id);
-      file.type = 'js';
-      file.src = es5.code;
-    } catch (err) {
-      debug('failed to compile: %s', file.id);
-      throw new Error(err.message);
-    }
+    var duo = file.duo;
+    var es5 = yield run(duo, file, o, only, ignore);
+    file.src = es5.code;
+    file.type = 'js';
   };
 }
 
+/**
+ * Run the compilation, but utilizes the cache if available.
+ *
+ * @param {Duo} duo         Duo instance
+ * @param {File} file       File to be compiled
+ * @param {Object} options  User-defined config
+ * @param {Array} only      User-defined whilelist
+ * @param {Array} ignore    User-defined blacklist
+ * @returns {Object}        Results of babel compile
+ */
+
+function* run(duo, file, options, only, ignore) {
+  var cache = yield duo.getCache();
+  if (!cache) {
+    debug('cache not enabled for %s', file.id);
+    return compile(duo, file, options, only, ignore);
+  }
+
+  var key = [ duo.hash(file.src), duo.hash(options) ];
+  var cached = yield cache.plugin('babel', key);
+  if (cached) {
+    debug('retrieved %s from cache', file.id);
+    return cached;
+  }
+
+  var results = compile(duo, file, options, only, ignore);
+  yield cache.plugin('babel', key, results);
+  debug('saved %s to cache', file.id);
+  return results;
+}
+
+/**
+ * Compiles the file given options from user.
+ */
+
+function compile(duo, file, options, only, ignore) {
+  var root = duo.root();
+  var sourceMap = duo.sourceMap();
+
+  var o = extend(true, {
+    ast: false,
+    filename: file.path,
+    filenameRelative: file.id,
+    sourceMap: sourceMap ? 'inline' : false,
+    sourceRoot: '/',
+    only: prepend(only, root),
+    ignore: prepend(ignore, root)
+  }, options);
+
+  debug('attempting to compile: %s', file.id, o);
+  var es5 = babel.transform(file.src, o);
+  if (file.src === es5.code) debug('did not compile: %s', file.id);
+  return es5;
+}
+
 /**
  * Prepend a value to each item in the given array.
  *

package.json

@@ -20,7 +20,8 @@
   },
   "devDependencies": {
     "convert-source-map": "^1.0.0",
-    "duo": "^0.11.2",
-    "mocha": "^2.2.4"
+    "duo": "^0.13.0",
+    "mocha": "^2.2.4",
+    "rimraf": "^2.4.1"
   }
 }

test/index.js

@@ -4,16 +4,21 @@
  */
 
 var assert = require('assert');
+var babel = require('..');
 var convert = require('convert-source-map');
 var Duo = require('duo');
 var path = require('path');
-var babel = require('..');
+var rm = require('rimraf').sync;
 var vm = require('vm');
 
 /**
  * Tests
  */
 
+after(function () {
+  rm(path.join(__dirname, 'components/duo-cache'));
+});
+
 describe('duo-babel', function() {
   it('should compile .js', function(done) {
     build('simple.js').run(function(err, src) {
@@ -121,6 +126,29 @@ describe('duo-babel', function() {
         done();
       });
   });
+
+  describe('with cache enabled', function () {
+    it('should still work', function(done) {
+      build('simple.js').cache(true).run(done);
+    });
+
+    it('should be significantly faster', function(done) {
+      var timer1 = timer();
+      build('simple.js').run(function (err, src) {
+        if (err) return done(err);
+        var noCache = timer1();
+
+        var timer2 = timer();
+        build('simple.js').cache(true).run(function (err, src) {
+          if (err) return done(err);
+
+          var withCache = timer2();
+          assert(withCache < noCache / 2);
+          done();
+        });
+      });
+    });
+  });
 });
 
 /**
@@ -149,3 +177,18 @@ function evaluate(src, ctx) {
   ctx = ctx || { console: console };
   return vm.runInNewContext(src, ctx)(1);
 }
+
+/**
+ * Create a timer. The function returned should be called
+ * later and it will return the number of ms since it was
+ * created.
+ *
+ * @returns {Function}
+ */
+
+function timer() {
+  var now = (new Date()).getTime();
+  return function () {
+    return (new Date()).getTime() - now;
+  };
+}

test/mocha.opts

@@ -0,0 +1 @@
+--harmony-generators