Refactoring themes

lib/theme.js

@@ -1,8 +1,12 @@
 var get = require('lodash.get');
 var isEmpty = require('lodash.isempty');
 var identity = require('lodash.identity');
+var partial = require('lodash.partial');
+var memoize = require('lodash.memoize');
 var chalk = require('chalk');
 
+// Translates strings like 'red, underline, bold'
+// into function chalk.red.underline.bold(text)
 function buildStylingFunction(styles) {
   if (isEmpty(styles)) {
     return identity;
@@ -15,32 +19,22 @@ function buildStylingFunction(styles) {
 var Theme = function(options) {
   var theme = options;
 
-  function renderPart(partName, text) {
+  var renderPart = function(partName, text) {
     var styles = theme[partName];
     var stylingFunction = buildStylingFunction(styles);
     return stylingFunction(text);
-  }
-
-  return {
-    renderName: function(text) {
-      return renderPart('name', text);
-    },
-
-    renderDescription: function(text) {
-      return renderPart('description', text);
-    },
-
-    renderExampleDescription: function(text) {
-      return renderPart('exampleDescription', text);
-    },
+  };
 
-    renderExampleCode: function(text) {
-      return renderPart('exampleCode', text);
-    },
+  var renderPartMemoized = function(partName) {
+    return memoize(partial(renderPart, partName));
+  };
 
-    renderExampleArgument: function(text) {
-      return renderPart('exampleArgument', text);
-    }
+  return {
+    renderName: renderPartMemoized('name'),
+    renderDescription: renderPartMemoized('description'),
+    renderExampleDescription: renderPartMemoized('exampleDescription'),
+    renderExampleCode: renderPartMemoized('exampleCode'),
+    renderExampleArgument: renderPartMemoized('exampleArgument')
   };
 };
 

package.json

@@ -57,6 +57,8 @@
     "lodash.isempty": "~4.1.3",
     "lodash.last": "~3.0.0",
     "lodash.map": "~4.2.0",
+    "lodash.memoize": "~4.0.1",
+    "lodash.partial": "~4.1.2",
     "lodash.sample": "~4.1.0",
     "lodash.unescape": "~4.0.0",
     "marked": "~0.3.5",