Merge pull request #5 from cloudfour/feature-rewrite_options_merging

Options Merging Rewrite

src/options.js

@@ -1,4 +1,5 @@
 import Handlebars from 'handlebars';
+import { merge } from './utils';
 
 const defaults = {
   templates: {
@@ -15,22 +16,7 @@ const defaults = {
  * @return {object} merged options
  */
 function mergeDefaults (options = {}) {
-  /* eslint-disable prefer-const */
-  let { result = defaults } = options;
-  let {
-    templates: {
-      handlebars = defaults.templates.handlebars,
-      helpers    = defaults.templates.helpers,
-      layouts    = defaults.templates.layouts,
-      pages      = defaults.templates.pages,
-      partials   = defaults.templates.partials
-    } = {}
-  } = options;
-  result = {
-    templates: { handlebars, helpers, layouts, pages, partials }
-  };
-  /* eslint-enable prefer-const */
-  return result;
+  return merge(defaults, options);
 }
 
 /**
@@ -45,23 +31,35 @@ function mergeDefaults (options = {}) {
  */
 function translateOptions (options = {}) {
   /* eslint-disable prefer-const */
-  let { result = defaults } = options;
-  let {
-    templates: {
-      handlebars = options.handlebars,
-      helpers    = options.helpers,
-      layouts    = options.layouts,
-      pages      = options.views,
-      partials   = options.layoutIncludes
-    } = {}
+  const {
+    handlebars,
+    helpers,
+    layouts,
+    views: pages,
+    layoutIncludes: partials
   } = options;
-  result = {
-    templates: { handlebars, helpers, layouts, pages, partials }
+
+  const result = {
+    templates: {
+      handlebars,
+      helpers,
+      layouts,
+      pages,
+      partials
+    }
   };
   return result;
   /* eslint-enable prefer-const */
 }
 
 const parseOptions = options => mergeDefaults(translateOptions(options));
 
+/**
+ * Sigh...
+ * > Single exports and multiple exports are mutually exclusive. You have to use
+ * > either one the two styles. Some modules combine both styles as follows:
+ * http://www.2ality.com/2015/12/babel-commonjs.html
+ */
+parseOptions.translator = translateOptions;
+
 export default parseOptions;

src/utils.js

@@ -88,10 +88,31 @@ function titleCase (str) {
     .replace(/\w\S*/g, word => word.charAt(0).toUpperCase() + word.substr(1));
 }
 
+/**
+ * Perform a deep merge of two objects.
+ * @param {Object} target
+ * @param {Object} source
+ * @return {Object}
+ * @example merge(defaults, options);
+ */
+function merge (target, source) {
+  Object.keys(source).forEach(key => {
+    if (Object.isExtensible(source[key])) {
+      merge(target[key], source[key]);
+    } else {
+      if (typeof source[key] !== 'undefined') {
+        target[key] = source[key];
+      }
+    }
+  });
+  return target;
+}
+
 export { dirname,
          getFiles,
          isGlob,
          keyname,
+         merge,
          parentDirname,
          readFiles,
          readFilesKeyed,

test/index.js

@@ -4,7 +4,7 @@ var expect = chai.expect;
 var builder = require('../dist/');
 
 const options = {
-  template: {
+  templates: {
     partials: `${__dirname}/fixtures/partials/*`,
     helpers: `${__dirname}/fixtures/helpers/*.js`
   }

test/options.js

@@ -2,6 +2,7 @@
 var chai = require('chai');
 var expect = chai.expect;
 var parseOptions = require('../dist/options');
+var translateOptions = parseOptions.translator;
 
 describe ('drizzle-builder', () => {
   describe ('options', () => {
@@ -12,6 +13,14 @@ describe ('drizzle-builder', () => {
       });
     });
     describe ('translating options from fabricator', () => {
+      // This PASSES. Where on Earth are the `undefined`s coming from?
+      it ('should work', () => {
+        var actual = translateOptions({ views: 'myViews' });
+        var expected = {
+          templates: { pages: 'myViews' }
+        };
+        expect(actual, expected).to.be.equal;
+      });
       it ('should translate template options', () => {
         var opts = parseOptions({
           layoutIncludes: 'a path',

test/utils.js

@@ -81,4 +81,14 @@ describe ('utils', () => {
       expect(parent).to.equal('helpers');
     });
   });
+  describe('merge()', () => {
+    it ('works', () => {
+      var actual = utils.merge(
+        {a: 1, c: {d: 3}},
+        {a: 2, b: 1, c: {e: 4}}
+      );
+      var expected = {a: 2, b: 1, c: {d: 3, e: 4}};
+      expect(actual, expected).to.be.equal;
+    });
+  });
 });