Customizing Visual Studio Compare and Merge Utility

Are you missing your favorite file compare utility because TFS ships diffmerge utility? No doubt the it has solid merge utility but compare only shows horizontal comparison and leaves us without any clue about what’s changed in the highlighted (until we manually find the change in highlighted line).

I have many time tired gvim to compare 2 files. Here is a trick by which you can put your ‘favorite utility’ on fire.

Go to Visual Studio -> Tools -> Option -> Source Control -> Visual Studio TFS. Click on ‘Configure User Tools…”. Here you can configure your ‘Compare’ and ‘Merge’ tools separately.

This is my configuration:

Extension: .cs
Operation: Compare
Command: C:\Program Files\Vim\vim71\gvim.exe (you have to fully qualify the path. Specific for GVim, add C:\Program Files\Vim\vim71 to your $Path)
Arguments: -dR %1 %2

Also, you can pass various arguments for existing diffmerge utility. Here is example to pass ‘ignorespace’ argument.

Extension: .cs
Operation: Merge
Command: C:\Program Files\Microsoft Visual Studio 9.0\Common7\IDE\diffmerge.exe
Arguments: /ignorespace /merge %1 %2 %3 %4 %6 %7

Although /ignorespace is not a recommended but you may want that to do in some specific case.

See complete tutorial here... http://blogs.msdn.com/jmanning/articles/535573.aspx

“generator” element in .hbm file

Recently I was stuck in a peculiar problem where I couldn’t insert a new record in a table using NHibernate. It came out to be the .hbm file which was giving problem. Because our DO generators are written so well, we looked for the bug there at last.

NHibernate class generator always creates class thinking that the primary key will be ‘auto-generated’. But that table doesn’t have auto-generated primary key. And so the “generator” element was incorrectly set to ‘native’ (i.e. auto-generated) for that table.

About “generator” element:

If the value of this is set to ‘native’, the key is auto-generated. Set ‘specified’ to set the primary key yourself in code. See link below for description of all values that generator can have. Note that ‘specified’ is the default in case “generator” element is absent in hbm file.

Link: http://www.roseindia.net/hibernate/hibernateidgeneratorelement.shtml

Throw Exception

You might have figured out ‘Find 10 difference’ column in from your favorite news paper. Here comes it again with finding one difference that affects your code:

try
{
}

catch (Exception)
{
throw;
}

and

try
{
}

catch (Exception ex)
{
throw ex;
}

Answer: In case of ‘rethrowing’ exception, 1^st case would still save the stack trace. Re-throwing the same exception in 2^nd case will result into losing your stack trace.