First working version

README.md

@@ -1,6 +1,15 @@
 # metalsmith-code-highlight
 
-Finds content with `<code>` elements and highlights it using [HighlightJS](https://highlightjs.org/).
+Finds content with `<code>` elements and highlights it using [HighlightJS](https://github.com/isagalaev/highlight.js).
+
+## Configuration
+
+Supports the [Highlight.js options](http://highlightjs.readthedocs.org/en/latest/api.html#configure-options):
+
+* `tabReplace`
+* `useBR`
+* `classPrefix`
+* `languages`
 
 ## Alternatives
 

index.js

@@ -0,0 +1,82 @@
+var domino = require('domino'),
+    highlight = require('highlight.js');
+
+var window, document, container;
+
+var HTML_FILENAME_REGEXP = /\.html$/,
+    CODE_LANGUAGE_REGEXP = /(?:^|\w)lang-(.+)(?:$|\w)/;
+
+/**
+ * @param {!HTMLElement} element
+ * @return {?string} Null if not found
+ */
+var getLanguage = function(element) {
+  var match;
+
+  if (element.className) {
+    match = element.className.match(CODE_LANGUAGE_REGEXP);
+
+    if (match) {
+      return match[1];
+    }
+  }
+  return null;
+};
+
+/**
+ * @param {!string} html
+ * @return {!string} New HTML with code highlighted
+ */
+var highlightFile = function(html) {
+  var i, len, codeBlocks, codeBlock, lang, result;
+
+  // Parse HTML into DOM
+  window = window || domino.createWindow('');
+  document = window.document;
+  container = document.createElement('div');
+
+  container.innerHTML = html;
+
+  codeBlocks = container.querySelectorAll('code');
+  for(i = 0, len = codeBlocks.length; i < len; i++) {
+    codeBlock = codeBlocks[i];
+    lang = getLanguage(codeBlock);
+
+    if (lang) {
+      result = highlight.highlight(lang, codeBlock.innerHTML, true);
+    }
+    else {
+      result = highlight.highlightAuto(codeBlock.innerHTML);
+      if (result.language) {
+        codeBlock.classList.add('lang-' + result.language);
+      }
+    }
+
+    codeBlock.innerHTML = result.value;
+  }
+
+  return container.innerHTML;
+};
+
+module.exports = function(options) {
+  highlight.configure(options);
+
+  /**
+   * @param {Object} files
+   * @param {Metalsmith} metalsmith
+   * @param {Function} done
+   */
+  return function(files, metalsmith, done) {
+    var file, data;
+    for (file in files) {
+      if (HTML_FILENAME_REGEXP.test(file)) {
+        data = files[file];
+        data.contents = new Buffer(
+          highlightFile(data.contents.toString())
+        );
+      }
+    }
+
+    setImmediate(done);
+  }
+}

package.json

@@ -0,0 +1,28 @@
+{
+  "name": "metalsmith-code-highlight",
+  "version": "0.0.1",
+  "description": "Metalsmith plugin for adding syntax highlighting to code within posts",
+  "main": "index.js",
+  "scripts": {
+    "test": "node test.js"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/fortes/metalsmith-code-highlight.git"
+  },
+  "keywords": [
+    "metalsmith",
+    "syntax",
+    "highlight"
+  ],
+  "author": "Filipe Fortes",
+  "license": "ISC",
+  "bugs": {
+    "url": "https://github.com/fortes/metalsmith-code-highlight/issues"
+  },
+  "homepage": "https://github.com/fortes/metalsmith-code-highlight",
+  "dependencies": {
+    "domino": "^1.0.18",
+    "highlight.js": "^8.2.0"
+  }
+}

test.js

@@ -0,0 +1,48 @@
+var assert = require('assert'),
+    metalsmithCodeHighlight = require('./index');
+
+var files = {
+  'bogus.jpg': {
+    contents: new Buffer('<code class=lang-js>// Hi</code>')
+  },
+  'code.html': {
+    contents: new Buffer('<code class=lang-js>// Hi</code>')
+  },
+  'double.html': {
+    contents: new Buffer(
+      '<p>Hello there.</p>' +
+      '<p>Inline <code class=lang-js>document.all</code></p>' +
+      '<pre><code>' +
+      '\nrequire "fs"\nconsole.log fs.readFileSync "/etc/passwd"' +
+      '</code></pre>'
+    )
+  }
+}
+
+var plugin = metalsmithCodeHighlight();
+
+plugin(files, {}, function(err) {
+  assert.equal(
+    files['code.html'].contents.toString(),
+    '<code class="lang-js"><span class="hljs-comment">// Hi</span></code>'
+  )
+
+  assert.equal(
+    files['double.html'].contents.toString(),
+    ('<p>Hello there.</p><p>Inline <code class="lang-js">' +
+    '<span class="hljs-built_in">document</span>.all</code></p>' +
+    '<pre><code class="lang-coffeescript">\n' +
+    '<span class="hljs-built_in">require</span> ' +
+    '<span class="hljs-string">"fs"</span>\n' +
+    '<span class="hljs-built_in">console</span>.log fs.readFileSync ' +
+    '<span class="hljs-string">"/etc/passwd"</span></code></pre>')
+  )
+
+  // Don't touch non-HTML files
+  assert.equal(
+    files['bogus.jpg'].contents.toString(),
+    '<code class=lang-js>// Hi</code>'
+  )
+
+  console.log("All tests passed");
+});