Allow pass options to parser

Add wrapper over posthtml-parser as requested in posthtml/posthtml/pull/150#issuecomment-232707133;
Add tests to cover possible wrapper issues;

Add isobject dependency

Author: kisenka

index.js

@@ -1,13 +1,20 @@
 'use strict';
 
 var htmlparser = require('htmlparser2');
+var isObject = require('isobject');
+
+/**
+ * @see https://github.com/fb55/htmlparser2/wiki/Parser-options
+ */
+var defaultOptions = {lowerCaseTags: false};
 
 /**
  * Parse html to PostHTMLTree
  * @param  {String} html
- * @return {Object}
+ * @param  {Object} [options=defaultOptions]
+ * @return {PostHTMLTree}
  */
-module.exports = function postHTMLParser(html) {
+function postHTMLParser(html, options) {
     var bufArray = [],
         results = [];
 
@@ -67,10 +74,30 @@ module.exports = function postHTMLParser(html) {
             last.content || (last.content = []);
             last.content.push(text);
         }
-    }, {lowerCaseTags: false});
+    }, options || defaultOptions);
 
     parser.write(html);
     parser.end();
 
     return results;
-};
+}
+
+function parserWrapper() {
+    var option;
+
+    function parser(html) {
+        var opt = option || defaultOptions;
+        return postHTMLParser(html, opt);
+    }
+
+    if (arguments.length === 1 && isObject(arguments[0])) {
+        option = arguments[0];
+        return parser;
+    }
+
+    option = arguments[1];
+    return parser(arguments[0]);
+}
+
+module.exports = parserWrapper;
+module.exports.defaultOptions = defaultOptions;

package.json

@@ -25,13 +25,17 @@
   },
   "homepage": "https://github.com/posthtml/posthtml-parser#readme",
   "dependencies": {
-    "htmlparser2": "^3.8.3"
+    "htmlparser2": "^3.8.3",
+    "isobject": "^2.1.0"
   },
   "devDependencies": {
     "chai": "^3.3.0",
     "istanbul": "^0.4.0",
     "jscs": "^2.3.5",
     "jshint": "^2.8.0",
-    "mocha": "^2.3.3"
+    "mocha": "^2.3.3",
+    "rewire": "^2.5.2",
+    "sinon": "^1.17.4",
+    "sinon-chai": "^2.8.0"
   }
 }

test/test.js

@@ -1,9 +1,55 @@
 var parser = require('..');
+var parserWithMockedDeps = require('rewire')('..');
 var describe = require('mocha').describe;
 var it = require('mocha').it;
-var expect = require('chai').expect;
+var beforeEach = require('mocha').beforeEach;
+var chai = require('chai');
+var sinon = require('sinon');
+var expect = chai.expect;
+chai.use(require('sinon-chai'));
 
 describe('PostHTML-Parser test', function() {
+    describe('Call signatures', function() {
+        var customOptions = {lowerCaseTags: false, lowerCaseAttributeNames: false};
+        var MockedHtmlParser2;
+        var parserSpy;
+
+        beforeEach(function() {
+            // jscs:disable requireFunctionDeclarations
+            MockedHtmlParser2 = function() {};
+            MockedHtmlParser2.prototype = {
+                write: function() {},
+                end: function() {}
+            };
+            // jscs:enable requireFunctionDeclarations
+
+            // Create spy on mocked htmlparser2 to collect call stats
+            parserSpy = sinon.spy(MockedHtmlParser2);
+
+            // Replace real htmlparser2 dependency of posthtml-parser with mocked
+            parserWithMockedDeps.__set__({
+                htmlparser: {Parser: parserSpy}
+            });
+        });
+
+        it('should use default options when called with 1 param', function() {
+            parserWithMockedDeps('');
+            expect(parserSpy.firstCall.args[1]).to.eql(parser.defaultOptions);
+        });
+
+        it('should use custom options when called with 2 params', function() {
+            parserWithMockedDeps('', customOptions);
+            expect(parserSpy.firstCall.args[1]).to.eql(customOptions);
+        });
+
+        it('should use custom params when called as factory function', function() {
+            var factory = parserWithMockedDeps(customOptions);
+            expect(factory).to.be.a('function');
+            expect(factory('')).to.be.an('array');
+            expect(parserSpy.firstCall.args[1]).to.eql(customOptions);
+        });
+    });
+
     it('should be parse doctype in uppercase', function() {
         expect(parser('<!DOCTYPE html>')).to.eql(['<!DOCTYPE html>']);
     });