Add example, stop modifying files array, rename "styles".

example/bad.md

@@ -0,0 +1,3 @@
+#bad.md
+
+#This file fails	some rules.

example/good.md

@@ -0,0 +1,3 @@
+# good.md
+
+This file passes all rules.

example/standalone.js

@@ -0,0 +1,21 @@
+"use strict";
+
+var markdownlint = require("../lib/markdownlint");
+
+var options = {
+  "files": [ "good.md", "bad.md" ]
+};
+
+// Uses result.toString for pretty formatting
+markdownlint(options, function callback(err, result) {
+  if (!err) {
+    console.log(result.toString());
+  }
+});
+
+// Examines the result object directly
+markdownlint(options, function callback(err, result) {
+  if (!err) {
+    console.dir(result, { "colors": true });
+  }
+});

lib/markdownlint.js

@@ -77,7 +77,7 @@ function lintFile(file, config, callback) {
 module.exports = function markdownlint(options, callback) {
   options = options || {};
   callback = callback || function noop() {};
-  var files = options.files || [];
+  var files = (options.files || []).slice();
   var config = options.config || { "default": true };
   var results = new Results();
   function lintFiles() {

package.json

@@ -17,7 +17,8 @@
     "test": "nodeunit",
     "test-cover": "istanbul cover node_modules/nodeunit/bin/nodeunit",
     "debug": "node debug node_modules/nodeunit/bin/nodeunit",
-    "lint": "eslint lib test"
+    "lint": "eslint lib test & eslint --rule \"no-console: 0\" example",
+    "example": "cd example & node standalone.js"
   },
   "dependencies": {
     "markdown-it": "^3.0.7"

test/markdownlint-test.js

@@ -118,6 +118,20 @@ module.exports.resultFormatting = function resultFormatting(test) {
   });
 };
 
+module.exports.filesNotModified = function filesNotModified(test) {
+  test.expect(2);
+  var files = [
+    "./test/atx_header_spacing.md",
+    "./test/first_header_bad_atx.md"
+  ];
+  var expectedFiles = files.slice();
+  markdownlint({ "files": files }, function callback(err) {
+    test.ifError(err);
+    test.deepEqual(files, expectedFiles, "Files modified.");
+    test.done();
+  });
+};
+
 module.exports.missingOptions = function missingOptions(test) {
   test.expect(2);
   markdownlint(null, function callback(err, result) {