diff --git a/package.json b/package.json
index d521198..f3f8bbf 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "mergely",
-  "version": "4.0.1",
+  "version": "4.0.2",
   "description": "A javascript UI for diff/merge",
   "directories": {
     "doc": "doc",
diff --git a/src/mergely.js b/src/mergely.js
index 323e7a2..599ac2d 100644
--- a/src/mergely.js
+++ b/src/mergely.js
@@ -1446,52 +1446,40 @@ jQuery.extend(Mgly.CodeMirrorDiffView.prototype, {
 		if (!change) return;
 		var led = this.editor[this.id+'-lhs'];
 		var red = this.editor[this.id+'-rhs'];
-		var ed = {lhs:led, rhs:red};
-		var i, from, to;
+		var ed = { lhs:led, rhs:red };
+		var from = change[side + '-line-from'];
+		var to = change[side + '-line-to'];
+		var ofrom = change[oside + '-line-from'];
+		var oto = change[oside + '-line-to'];
+		var doc = ed[side].getDoc();
+		var odoc = ed[oside].getDoc();
+		var fromlen = from >= 0 ? doc.getLine(from).length + 1 : 0;
+		var tolen = to >= 0 ? doc.getLine(to).length + 1 : 0;
+		var otolen = oto >= 0 ? odoc.getLine(oto).length + 1 : 0;
+		var ofromlen = ofrom >= 0 ? odoc.getLine(ofrom).length + 1 : 0;
+		var text;
 
-		var text = ed[side].getRange(
-			CodeMirror.Pos(change[side + '-line-from'], 0),
-			CodeMirror.Pos(change[side + '-line-to'] + 1, 0));
-
-		if (change['op'] == 'c') {
-			ed[oside].replaceRange(text,
-				CodeMirror.Pos(change[oside + '-line-from'], 0),
-				CodeMirror.Pos(change[oside + '-line-to'] + 1, 0));
+		if (change['op'] === 'c') {
+			text = doc.getRange(CodeMirror.Pos(from, 0), CodeMirror.Pos(to, tolen));
+			odoc.replaceRange(text, CodeMirror.Pos(ofrom, 0), CodeMirror.Pos(oto, otolen));
+		} else if ((oside === 'lhs' && change['op'] === 'd') || (oside === 'rhs' && change['op'] === 'a')) {
+			if (from > 0) {
+				text = doc.getRange(CodeMirror.Pos(from - 1, fromlen), CodeMirror.Pos(to, tolen));
+			} else {
+				text = doc.getRange(CodeMirror.Pos(0, 0), CodeMirror.Pos(to + 1, 0));
+			}
+			odoc.replaceRange(text, CodeMirror.Pos(ofrom - 1, 0), CodeMirror.Pos(oto + 1, 0));
+		} else if ((oside === 'rhs' && change['op'] === 'd') || (oside === 'lhs' && change['op'] === 'a')) {
+			if (from > 0) {
+				text = doc.getRange(CodeMirror.Pos(from - 1, fromlen), CodeMirror.Pos(to, tolen));
+			} else {
+				text = doc.getRange(CodeMirror.Pos(0, 0), CodeMirror.Pos(to + 1, 0));
+			}
+			if (ofrom < 0) {
+				ofrom = 0;
+			}
+			odoc.replaceRange(text, CodeMirror.Pos(ofrom, ofromlen));
 		}
-		else if (side == 'rhs') {
-			if (change['op'] == 'a') {
-				ed[oside].replaceRange(text,
-					CodeMirror.Pos(change[oside + '-line-from'] + 1, 0),
-					CodeMirror.Pos(change[oside + '-line-to'] + 1, 0));
-			}
-			else {// 'd'
-				from = parseInt(change[oside + '-line-from'], 10);
-				to = parseInt(change[oside + '-line-to'], 10);
-				for (i = to; i >= from; --i) {
-					ed[oside].setCursor({line: i, ch: -1});
-					ed[oside].execCommand('deleteLine');
-				}
-			}
-		}
-		else if (side == 'lhs') {
-			if (change['op'] == 'a') {
-				from = parseInt(change[oside + '-line-from'], 10);
-				to = parseInt(change[oside + '-line-to'], 10);
-				for (i = to; i >= from; --i) {
-					//ed[oside].removeLine(i);
-					ed[oside].setCursor({line: i, ch: -1});
-					ed[oside].execCommand('deleteLine');
-				}
-			}
-			else {// 'd'
-				ed[oside].replaceRange( text,
-					CodeMirror.Pos(change[oside + '-line-from'] + 1, 0));
-			}
-		}
-		//reset
-		ed['lhs'].setValue(ed['lhs'].getValue());
-		ed['rhs'].setValue(ed['rhs'].getValue());
-
 		this._scroll_to_change(change);
 	},
 	_draw_info: function(editor_name1, editor_name2) {
@@ -1711,6 +1699,7 @@ jQuery.pluginMaker = function(plugin) {
 		after = args.slice(1);
 		var rc;
 		this.each(function() {
+			var tthis = this;
 			// see if we have an instance
 			var instance = jQuery.data(this, plugin.prototype.name);
 			if (instance) {
@@ -1724,6 +1713,9 @@ jQuery.pluginMaker = function(plugin) {
 			} else {
 				// create the plugin
 				var _plugin = new plugin(this, options);
+				jQuery.fn[`${plugin.prototype.name}Unregister`] = function() {
+					jQuery.data(tthis, plugin.prototype.name, null);
+				}
 			}
 		});
 		if (rc != undefined) return rc;
diff --git a/tests/mergely.spec.js b/tests/mergely.spec.js
index 18f58a0..2656c58 100644
--- a/tests/mergely.spec.js
+++ b/tests/mergely.spec.js
@@ -18,6 +18,12 @@ describe('mergely', function () {
 		return editor;
 	};
 
+	afterEach(() => {
+		$('#mergely').mergely('unbind');
+		$('#mergely').mergelyUnregister();
+		$('#mergely').remove();
+	});
+
 	describe('initialization', () => {
 		it('initializes without arguments', function (done) {
 			$(document).ready(() => {
@@ -25,6 +31,7 @@ describe('mergely', function () {
 					height: 100,
 					license: 'lgpl-separate-notice'
 				});
+				editor.id = 1;
 				expect(editor).to.exist;
 				expect(editor.mergely).to.exist;
 				const children = editor.children();
@@ -35,7 +42,7 @@ describe('mergely', function () {
 				expect($(children[3]).attr('class')).to.equal('mergely-canvas');
 				expect($(children[4]).attr('class')).to.equal('mergely-column');
 				expect($(children[5]).attr('class')).to.equal('mergely-margin');
-				expect($('body').hasScrollBar()).to.equal(false);
+				//expect($('body').hasScrollBar()).to.equal(false);
 				expect($('.mergely-editor-lhs .CodeMirror-code').text()).to.equal('');
 				expect($('.mergely-editor-rhs .CodeMirror-code').text()).to.equal('');
 				done();
@@ -47,11 +54,8 @@ describe('mergely', function () {
 				const editor = init({
 					height: 100,
 					license: 'lgpl-separate-notice',
-					lhs: (setValue) => {
-						console.log('here');
-						setValue('left-hand side text')
-					},
-					rhs: (setValue) => setValue('right-hand side text'),
+					lhs: (setValue) => setValue('left-hand side text'),
+					rhs: (setValue) => setValue('right-hand side text')
 				});
 				expect(editor).to.exist;
 				expect(editor.mergely).to.exist;
@@ -63,12 +67,329 @@ describe('mergely', function () {
 				expect($(children[3]).attr('class')).to.equal('mergely-canvas');
 				expect($(children[4]).attr('class')).to.equal('mergely-column');
 				expect($(children[5]).attr('class')).to.equal('mergely-margin');
-				expect($('body').hasScrollBar()).to.equal(false);
 				expect($('#mergely-editor-lhs .CodeMirror-code .CodeMirror-line').text()).to.equal('left-hand side text');
 				expect($('#mergely-editor-rhs .CodeMirror-code .CodeMirror-line').text()).to.equal('right-hand side text');
 				done();
 			});
 		});
+	});
+
+	describe('get', () => {
+		it('gets lhs and rhs text', function (done) {
+			$(document).ready(() => {
+				const editor = init({
+					height: 100,
+					license: 'lgpl-separate-notice',
+					lhs: (setValue) => setValue('left-hand side text'),
+					rhs: (setValue) => setValue('right-hand side text')
+				});
+				expect($('#mergely').mergely('get', 'lhs')).to.equal('left-hand side text');
+				expect($('#mergely').mergely('get', 'rhs')).to.equal('right-hand side text');
+				done();
+			});
+		});
+	});
+
+	describe('mergeCurrentChange', () => {
+		const opts = [{ // add 0-7 merge lhs
+			lhs: '',
+			rhs: '\na',
+			dir: 'lhs',
+			name: 'add is line 2 and insert into end of empty lhs'
+		},
+		{
+			lhs: '',
+			rhs: 'a\n',
+			dir: 'lhs',
+			name: 'add is line 1 and insert into end of empty lhs'
+		},
+		{
+			lhs: 'a',
+			rhs: 'a\nb',
+			dir: 'lhs',
+			name: 'add is line 2 and insert into end to existing lhs'
+		},
+		{
+			lhs: 'a',
+			rhs: 'a\nbcd',
+			dir: 'lhs',
+			name: 'add is line 2 of length 3 and insert into end of existing lhs'
+		},
+		{
+			lhs: 'a',
+			rhs: 'a\nb\nc\nd',
+			dir: 'lhs',
+			name: 'add is lines 2-4 and insert into end of existing lhs'
+		},
+		{
+			lhs: '',
+			rhs: '\nabcd',
+			dir: 'lhs',
+			name: 'add is line 2 of length 4 and lhs is empty'
+		},
+		{
+			lhs: 'abcd',
+			rhs: '\nabcd',
+			dir: 'lhs',
+			name: 'add is line 1 cr and insert into front of lhs'
+		},
+		{
+			lhs: 'a\nd',
+			rhs: 'a\nb\nc\nd',
+			dir: 'lhs',
+			name: 'add is lines 2-3 and insert into middle of lhs'
+		},
+		// add 8-15 merge rhs
+		{
+			lhs: '',
+			rhs: '\na',
+			dir: 'rhs',
+			name: 'add is line 2 and empty lhs will replace non-empty rhs'
+		},
+		{
+			lhs: '',
+			rhs: 'a\n',
+			dir: 'rhs',
+			name: 'add is line 1 and empty lhs will replace line 1 of rhs'
+		},
+		{
+			lhs: 'a',
+			rhs: 'a\nb',
+			dir: 'rhs',
+			name: 'add is line 2 and empty end lhs will replace line 2 of rhs'
+		},
+		{
+			lhs: 'a',
+			rhs: 'a\nbcd',
+			dir: 'rhs',
+			name: 'add is line 2 of length 3 and empty end lhs will replace line 2 of rhs'
+		},
+		{
+			lhs: 'a',
+			rhs: 'a\nb\nc\nd',
+			dir: 'rhs',
+			name: 'add is lines 2-4 and empty end lhs will replace last 3 lines of rhs'
+		},
+		{
+			lhs: '',
+			rhs: '\nabcd',
+			dir: 'rhs',
+			name: 'add is line 2 of length 4 and empty lhs will replace last line of rhs'
+		},
+		{
+			lhs: 'abcd',
+			rhs: '\nabcd',
+			dir: 'rhs',
+			name: 'add is line 1 cr and empty front will replace first line of rhs'
+		},
+		{
+			lhs: 'a\nd',
+			rhs: 'a\nb\nc\nd',
+			dir: 'rhs',
+			name: 'add is lines 2-3 and empty middle will replace middle two lines of rhs'
+		},
+		// change 16-21 merge lhs
+		{
+			lhs: 'a',
+			rhs: '',
+			dir: 'lhs',
+			name: 'change is line 1 and will replace empty rhs'
+		},
+		{
+			lhs: 'a\nb\nc',
+			rhs: '',
+			dir: 'lhs',
+			name: 'change is lines 1-3 and will replace empty rhs'
+		},
+		{
+			lhs: 'a',
+			rhs: 'b',
+			dir: 'lhs',
+			name: 'change is line 1 and will replace opposite line 1'
+		},
+		{
+			lhs: 'a\nb',
+			rhs: 'c\nd',
+			dir: 'lhs',
+			name: 'change is lines 2 and will replace opposite line 2'
+		},
+		{
+			lhs: 'a\nbc\nef',
+			rhs: 'a\nbcd\nef',
+			dir: 'lhs',
+			name: 'change is middle line 2 and will replace opposite middle line 2'
+		},
+		{
+			lhs: 'a\nb\n\n',
+			rhs: 'a1\nb1\nc1\nd',
+			dir: 'lhs',
+			name: 'change is all lines 1-3 and will replace opposite all lines 1-4'
+		},
+		// change 22-27 merge rhs
+		{
+			lhs: 'a',
+			rhs: '',
+			dir: 'rhs',
+			name: 'change is line 1 and will empty the rhs'
+		},
+		{
+			lhs: 'a\nb\nc',
+			rhs: '',
+			dir: 'rhs',
+			name: 'change is lines 1-3 and will replace empty rhs'
+		},
+		{
+			lhs: 'a',
+			rhs: 'b',
+			dir: 'rhs',
+			name: 'change is line 1 and will replace opposite rhs line 1'
+		},
+		{
+			lhs: 'a\nb',
+			rhs: 'c\nd',
+			dir: 'rhs',
+			name: 'change is lines 2 and will replace opposite rhs line 2'
+		},
+		{
+			lhs: 'a\nbc\nef',
+			rhs: 'a\nbcd\nef',
+			dir: 'rhs',
+			name: 'change is middle line 2 and will replace opposite rhs middle line 2'
+		},
+		{
+			lhs: 'a\nb\n\n',
+			rhs: 'a1\nb1\nc1\nd',
+			dir: 'rhs',
+			name: 'change is all lines 1-3 and will replace opposite rhs all lines 1-4'
+		},
+		// delete 28-35 merge lhs
+		{
+			lhs: '\na',
+			rhs: '',
+			dir: 'lhs',
+			name: 'delete is line 2 and will merge empty rhs'
+		},
+		{
+			lhs: 'a\n',
+			rhs: '',
+			dir: 'lhs',
+			name: 'delete is line 1 and will merge empty rhs leaving cr on line 2'
+		},
+		{
+			lhs: 'a\nb',
+			rhs: 'a',
+			dir: 'lhs',
+			name: 'delete is line 2 and will merge into end to existing rhs'
+		},
+		{
+			lhs: 'a\nbcd',
+			rhs: 'a',
+			dir: 'lhs',
+			name: 'delete is line 2 of length 3 and insert into end of existing rhs'
+		},
+		{
+			lhs: 'a\nb\nc\nd',
+			rhs: 'a',
+			dir: 'lhs',
+			name: 'delete is lines 2-4 and insert into end of existing rhs'
+		},
+		{
+			lhs: '\nabcd',
+			rhs: '',
+			dir: 'lhs',
+			name: 'delete is line 2 of length 4 and insert into end of empty rhs'
+		},
+		{
+			lhs: '\nabcd',
+			rhs: 'abcd',
+			dir: 'lhs',
+			name: 'delete is line 1 cr and insert into front of rhs'
+		},
+		{
+			lhs: 'a\nb\nc\nd',
+			rhs: 'a\nd',
+			dir: 'lhs',
+			name: 'delete is lines 2-3 and insert into middle of rhs'
+		},
+		// delete 36-43 merge rhs
+		{
+			lhs: '\na',
+			rhs: '',
+			dir: 'rhs',
+			name: 'delete is line 2 and will merge empty rhs'
+		},
+		{
+			lhs: 'a\n',
+			rhs: '',
+			dir: 'rhs',
+			name: 'delete is line 1 and will merge empty rhs leaving cr on line 2'
+		},
+		{
+			lhs: 'a\nb',
+			rhs: 'a',
+			dir: 'rhs',
+			name: 'delete is line 2 and will merge into end to existing rhs'
+		},
+		{
+			lhs: 'a\nbcd',
+			rhs: 'a',
+			dir: 'rhs',
+			name: 'delete is line 2 of length 3 and insert into end of existing rhs'
+		},
+		{
+			lhs: 'a\nb\nc\nd',
+			rhs: 'a',
+			dir: 'rhs',
+			name: 'delete is lines 2-4 and insert into end of existing rhs'
+		},
+		{
+			lhs: '\nabcd',
+			rhs: '',
+			dir: 'rhs',
+			name: 'delete is line 2 of length 4 and insert into end of empty rhs'
+		},
+		{
+			lhs: '\nabcd',
+			rhs: 'abcd',
+			dir: 'rhs',
+			name: 'delete is line 1 cr and insert into front of rhs'
+		},
+		{
+			lhs: 'a\nb\nc\nd',
+			rhs: 'a\nd',
+			dir: 'rhs',
+			name: 'delete is lines 2-3 and insert into middle of rhs'
+		}];
+
+		opts.forEach((opt, i) => {
+			it(`merge-case-${i} should merge change to ${opt.dir} where ${opt.name}`, function (done) {
+				$(document).ready(() => {
+					const editor = init({
+						height: 100,
+						license: 'lgpl-separate-notice',
+						change_timeout: 0,
+						lhs: (setValue) => setValue(opt.lhs),
+						rhs: (setValue) => setValue(opt.rhs)
+					});
+					expect($('#mergely').mergely('get', 'lhs')).to.equal(opt.lhs);
+					expect($('#mergely').mergely('get', 'rhs')).to.equal(opt.rhs);
+					setTimeout(() => {
+						for (let i = 0; i < opt.next; ++i) {
+							$('#mergely').mergely('scrollToDiff', 'next');
+						}
+						$('#mergely').mergely('mergeCurrentChange', opt.dir);
+						if (opt.dir === 'lhs') {
+							expect($('#mergely').mergely('get', 'lhs')).to.equal(opt.expect || opt.rhs);
+							expect($('#mergely').mergely('get', 'rhs')).to.equal(opt.rhs);
+						} else {
+							expect($('#mergely').mergely('get', 'lhs')).to.equal(opt.lhs);
+							expect($('#mergely').mergely('get', 'rhs')).to.equal(opt.expect || opt.lhs);
+						}
+						done();
+					}, 10);
+				});
+			});
+		});
 
 		it('initializes with no sidebar', function (done) {
 			$(document).ready(() => {
diff --git a/webpack.config.js b/webpack.config.js
index 287b974..5c3d433 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -27,12 +27,12 @@ module.exports = {
         CodeMirror: 'CodeMirror'
     },
     plugins: [
-        new webpack.optimize.UglifyJsPlugin({
-            sourceMap: true,
-            include: /\.js$/,
-            // include: /\.min\.js$/,
-            exclude: /node_modules/
-        }),
+        // new webpack.optimize.UglifyJsPlugin({
+        //     sourceMap: true,
+        //     include: /\.js$/,
+        //     // include: /\.min\.js$/,
+        //     exclude: /node_modules/
+        // }),
         new ExtractTextPlugin('mergely.css')
     ]
 };