Add test for highlightCode html modifier

lib/output/modifiers/__tests__/highlightCode.js

@@ -0,0 +1,63 @@
+jest.autoMockOff();
+
+var cheerio = require('cheerio');
+var Promise = require('../../../utils/promise');
+
+describe('highlightCode', function() {
+    var highlightCode = require('../highlightCode');
+
+    function doHighlight(lang, code) {
+        return {
+            text: '' + (lang || '') + '$' + code
+        };
+    }
+
+    function doHighlightAsync(lang, code) {
+        return Promise()
+        .then(function() {
+            return doHighlight(lang, code);
+        });
+    }
+
+    pit('should call it for normal code element', function() {
+        var $ = cheerio.load('<p>This is a <code>test</code></p>');
+
+        return highlightCode(doHighlight, $)
+        .then(function() {
+            var $code = $('code');
+            expect($code.text()).toBe('$test');
+        });
+    });
+
+    pit('should call it for markdown code block', function() {
+        var $ = cheerio.load('<pre><code class="lang-js">test</code></pre>');
+
+        return highlightCode(doHighlight, $)
+        .then(function() {
+            var $code = $('code');
+            expect($code.text()).toBe('js$test');
+        });
+    });
+
+    pit('should call it for asciidoc code block', function() {
+        var $ = cheerio.load('<pre><code class="language-python">test</code></pre>');
+
+        return highlightCode(doHighlight, $)
+        .then(function() {
+            var $code = $('code');
+            expect($code.text()).toBe('python$test');
+        });
+    });
+
+    pit('should accept async highlighter', function() {
+        var $ = cheerio.load('<pre><code class="language-python">test</code></pre>');
+
+        return highlightCode(doHighlightAsync, $)
+        .then(function() {
+            var $code = $('code');
+            expect($code.text()).toBe('python$test');
+        });
+    });
+});
+
+

lib/output/modifiers/editHTMLElement.js

@@ -8,7 +8,7 @@ function editHTMLElement($, selector, fn) {
 
     return Promise.forEach($elements, function(el) {
         var $el = $(el);
-        fn($el);
+        return fn($el);
     });
 }
 

lib/output/modifiers/highlightCode.js

@@ -0,0 +1,44 @@
+var Promise = require('../../utils/promise');
+var editHTMLElement = require('./editHTMLElement');
+
+/**
+    Highlight all code elements
+
+    @param {Function(lang, body) -> String} highlight
+    @param {HTMLDom} $
+    @return {Promise}
+*/
+function highlightCode(highlight, $) {
+    return editHTMLElement($, 'code', function($code) {
+        var classNames = ($code.attr('class') || '').split(' ');
+        var lang = classNames
+            .map(function(cl) {
+                // Markdown
+                if (cl.search('lang-') === 0) {
+                    return cl.slice('lang-'.length);
+                }
+
+                // Asciidoc
+                if (cl.search('language-') === 0) {
+                    return cl.slice('language-'.length);
+                }
+
+                return null;
+            })
+            .find(function(cl) {
+                return Boolean(cl);
+            });
+        var source = $code.text();
+
+        return Promise(highlight(lang, source))
+        .then(function(r) {
+            if (r.html) {
+                $code.html(r.html);
+            } else {
+                $code.text(r.text);
+            }
+        });
+    });
+}
+
+module.exports = highlightCode;

lib/output/modifiers/index.js

@@ -9,5 +9,6 @@ module.exports = {
     fetchRemoteImages:  require('./fetchRemoteImages'),
     svgToPng:           require('./svgToPng'),
     resolveLinks:       require('./resolveLinks'),
-    annotateText:       require('./annotateText')
+    annotateText:       require('./annotateText'),
+    highlightCode:      require('./highlightCode')
 };