New merge tool Semanticmerge, tested on SVN

This morning I saw a post of Scott Hanselman passing by on facebook:

“There’s as new code merging tool in town… “Semantic Merge – Plastic SCM” http://t.co/mlaqWnVGST Free Download of the Beta”

The welcome text on their site is very promising:

“a semantic merge tool…
that understands your code”

A project we’re working on at work is in a phase of a lot of refactoring’s. the base functionality seems to be working fine, we’re now taking care of better fault handling, better logging, better messaging, …

That includes a lot of refactoring’s, moving methods, adding log messages, updating methods in a team of 3 developers. That results in a lot of merge errors as we more then once make changes to the same files in the project.

The default text merge tool can’t handle these changes and more then once we’ve been fouling around for over an hour to get the files back to a ‘working’ state.

No SVN documentation

We still work with SVN for our internal projects. For my personal projects I’m hooked up to git in combination with GitHub as you probably can see in the different topics I blogged about before.

The guys from Semanticmerge placed some documentation how to configure the merge tool for git, TFS and Plastic SCM but they didn’t include documentation about configuring TortoiseSVN (the tool we are using).

On their UserVoice page there’s already a request for documentation on SVN and Tortoise.

Trial en error configuration

I didn’t wanted to wait for the upcoming documentation and decided to try and figure it out myself. I took the documentation for TFS for the semantic mergetool, the Diff/Merge configuration documentation on MSDN, the Tortoise documentation (search for merge tool) and a post on stackoverflow to combine the different parameters that have to be set.

After some attempts I think I got it running.

Setting Tortoise SVN options

First start with downloading the beta of the Semanticmerge tool and install it on your system. You’ll need the location where you installed the tool, note it during installation or you’re going to have to search your system for the executable needed in the next step.

In TortoiseSVN you can set the merge tool you want to use (default TortoiseMerge), this we’ll have to change to the semanticmerge tool. Right click on a folder and choose for ‘TortoiseSVN’ and then ‘Settings’.

In the settings screen go to ‘External Programs’ – ‘Merge Tool’. There you can set the path to the semanticmergetool.exe.

If you would try to merge now you’ll get an error message. The tool will be started but it doesn’t know witch files he have to merge. Those parameters will we have to add after the path to the executable.

After some searching I added following options:

So the complete command you have to fill out for the external merge tool:

"PATH-TO-semanticmergetool.exe" -s=%theirs -d=%mine -b=%base -r=%merged -sn=%yname -dn=%tname -bn=%bname -l=csharp -emt=default -edt=default

Testing

I’ve created a test class with 3 simple methods and committed this to our SVN server.

using System; namespace ZGroup.MonitoringSuite.TestApp { public class MergeTest { public void TestMethod1() { const string text = "This is the first test method"; var split = text.Split(' '); foreach (var s in split) { Console.WriteLine(s); } } public void TestMethod2() { const string text = "This is the second test method"; var split = text.Split(' '); foreach (var s in split) { Console.WriteLine(s); } } public void TestMethod3() { const string text = "This is the third test method"; var split = text.Split(' '); foreach (var s in split) { Console.WriteLine(s); } } } }

On one virtual machine I updated the source and added some changes in the file. I moved the second method under the third method and added some dummy code.

using System; namespace ZGroup.MonitoringSuite.TestApp { public class MergeTest { public void TestMethod1() { const string text = "This is the first test method"; var split = text.Split(' '); foreach (var s in split) { Console.WriteLine(s); } } public void TestMethod3() { const string text = "This is the third test method"; var split = text.Split(' '); foreach (var s in split) { Console.WriteLine(s); } } public void TestMethod2() { const string text = "This is the second test method"; var split = text.Split(' '); foreach (var s in split) { Console.WriteLine(s); } //We add some lines to this method so the line number doesn't match any more var split2 = text.Split(' '); foreach (var s in split2) { Console.WriteLine(s); } var split3 = text.Split(' '); foreach (var s in split3) { Console.WriteLine(s); } } } }

I then committed the file back to the server. On my machine I also changed the same file. I’ve added a test class under the existing class and added some dummy code to the second method (that is still the second method in row).

using System; using System.Collections.Generic; namespace ZGroup.MonitoringSuite.TestApp { public class MergeTest { public void TestMethod1() { const string text = "This is the first test method"; var split = text.Split(' '); foreach (var s in split) { Console.WriteLine(s); } } public void TestMethod2() { //Add some lines var tests = new List<Test>(); tests.Add(new Test() { Id = 1, Description = "This is a test" }); foreach (var test in tests) { Console.WriteLine(test.Description); } const string text = "This is the second test method"; var split = text.Split(' '); foreach (var s in split) { Console.WriteLine(s); } } public void TestMethod3() { const string text = "This is the third test method"; var split = text.Split(' '); foreach (var s in split) { Console.WriteLine(s); } } } public class Test { public long Id { get; set; } public string Description { get; set; } } }

When I then update my code on my machine I’ll see we have some merge errors (like expected).

If you then click on ‘Edit conflict’ the merge tool appears.

It indicates that Method2 is changed on both contributors. You can click the merge button to view how the tool automatically merge the files.

The moved method is nicely merged with the changes of the not moved method. Just like we wanted. The merged result:

using System; using System.Collections.Generic; namespace ZGroup.MonitoringSuite.TestApp { public class MergeTest { public void TestMethod1() { const string text = "This is the first test method"; var split = text.Split(' '); foreach (var s in split) { Console.WriteLine(s); } } public void TestMethod3() { const string text = "This is the third test method"; var split = text.Split(' '); foreach (var s in split) { Console.WriteLine(s); } } public void TestMethod2() { //Add some lines var tests = new List<Test>(); tests.Add(new Test() { Id = 1, Description = "This is a test" }); foreach (var test in tests) { Console.WriteLine(test.Description); } const string text = "This is the second test method"; var split = text.Split(' '); foreach (var s in split) { Console.WriteLine(s); } //We add some lines to this method so the line number doesn't match any more var split2 = text.Split(' '); foreach (var s in split2) { Console.WriteLine(s); } var split3 = text.Split(' '); foreach (var s in split3) { Console.WriteLine(s); } } } public class Test { public long Id { get; set; } public string Description { get; set; } } }

Conclusion

At first sight (the merged class wasn’t that difficult) the tool does what it has to do. I’m going to start using it on our project now and will see if some more complex merges will have the same result.

One of the problems I’m still facing is that for SVN the file doesn’t seems to be resolved automatically. I still have to find the file and right click and choose ‘resolved’. Or you can do that on a checkin but then you have to remember witch files you’ll already merged.

It can be it’s another parameter you’ll have to add to the command line expression but I couldn’t find any documentation.

DISCLAIMER: The configuration seems to be working on my system. I’m not 100% sure it’s the correct configuration. Use it on your own risk!

UPDATE: You can also use the samentic merge tool as diff viewer in TortoiseSVN.

11 thoughts on “New merge tool Semanticmerge, tested on SVN”

pablo 19 April 2013 at 12:44

Thanks Bart!

Conflicts are not yet resolved automatically because we prefer to get people used to SemanticMerge before… but it would be very, very easy to activate. In fact we didn’t do it so far on purpose, because all the tests pass with full automation 🙂

Reply ↓

Igor 21 April 2013 at 21:47

please, could you add settings for “Diff Viewer” too?

Reply ↓

Bart De Meyer Post author26 April 2013 at 10:23

Hey,
You can check out the post I wrote today: http://blog.bartdemeyer.be/2013/04/semanticmerge-diff-viewer-settings-for-svn/

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Pingback: Semanticmerge diff viewer settings for SVN | Bart De Meyer - Blog

Frank 19 June 2013 at 18:19

You could follow an example given by the BeyondCompare guys to automatically mark the file as resolved. Essentially, you have Tortise call a VB script which launches the merge tool and then once the merge tool exits it issues another command to Tortise to resolve the file.

See this thread for details: http://www.scootersoftware.com/vbulletin/showthread.php?t=3699

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pablo 1 August 2013 at 10:31

Hi Bart,

Have you seen our new Visual Merge? -> http://codicesoftware.blogspot.com/2013/07/semanticmerge-goes-visual.html

Reply ↓

Bart De Meyer Post author1 August 2013 at 11:00

Hey Pablo, looks nice!

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Daniel 12 January 2016 at 17:55

I have found that using the above configuration causes SemanticMerge to hang for a while when you try to merge a non-C# file. I would recommend leaving out the “-l=csharp” option from the merge configuration for this reason. Then SemanticMerge can decide on its own what the language is for the file based on the file extension, and either open the SemanticMerge proper or just open the text-based merge program for languages it doesn’t support. I personally also add in the ” –nolangwarn” to remove the pesky dialog box when SemanticMerge doesn’t support the language for the file.

Reply ↓

Gianluigi 26 October 2017 at 09:48

I’ve tried to configure AnkSVN as suggested (“PATH-TO-semanticmergetool.exe” -s=%theirs -d=%mine -b=%base -r=%merged -sn=%yname -dn=%tname -bn=%bname -l=csharp -emt=default -edt=default) with the real path but I get a “Duplicated argiment” error.

From my perspective it would be very useful to have a more speaking error and, eventually, a wizard that auto-set the properties like Beyond Compare or Code Compare are doing

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Bart De Meyer – Blog

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New merge tool Semanticmerge, tested on SVN

No SVN documentation

Trial en error configuration

Setting Tortoise SVN options

Testing

Conclusion

11 thoughts on “New merge tool Semanticmerge, tested on SVN”

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