Allow to set custom installation paths for supported diff tools

[ldeluigi]

Is the feature request related to a problem

I have a custom installation folder for both VS Code and Visual studio. The search paths for these diff tools don't match with the ones hard-coded inside DiffEngine.

Describe the solution

One should be able to set a custom path for diff tools, for example with the help of environment variables.
For example: DiffEngine_<DiffToolName>_Path = D:\My\Folder\

Describe alternatives considered

As alternative, consider reading a configuration file in the home directory of the user or in the project folder.

Additional context

If necessary ask me.

[SimonCropp]

you can add VS Code and Visual studio to you PATH variable

[ldeluigi]

you can add VS Code and Visual studio to you PATH variable

I did, but this is not enough. DiffEngine wants a specific executable file name and path.

[SimonCropp]

I did, but this is not enough. DiffEngine wants a specific executable file name and path.

that sounds like a bug. can you submit a failing test as a Pull Request. here is a test you can look at as a basis https://github.com/VerifyTests/DiffEngine/blob/main/src/DiffEngine.Tests/OsSettingsResolverTest.cs#L21

[ldeluigi]

I don't need to make a PR. The problem is simple and can be seen from the code. Look at this:

DiffEngine/src/DiffEngine/Implementation/VsCode.cs

Lines 19 to 23 in 4a90ff3

	Windows: new(
	"code.exe",
	launchArguments,
	@"%LocalAppData%\Programs\Microsoft VS Code\",
	@"%ProgramFiles%\Microsoft VS Code\"),

On Windows you are looking for a code.exe file in those directory or in the path. But in my Windows 10 system, visual studio code has a root directory with a Code.exe file, a bin directory with a code, code.cmd and a code-tunnel.exe file, which are all kind of equivalent but don't match code.exe (I think). The full path of my VS Code installation is F:\Programs\Microsoft VS Code.

General thoughts

It's not always a good idea to search the entire PATH of the system for a file named code.exe because any program can have such file and you are calling god knows what program that's named like that when you do so. Adding a custom, explicit manual configuration option would prevent such mistakes and give the user control over what's being done by DiffEngine in our systems. I've already set up a DiffEngine_ToolOrder variable to control priority, but none of the implementations I listed worked properly until I monkeypatched vs code by creating a code.exe file in the bin folder which is a copy of code-tunnel.exe. I'd also appreciate if DiffEngine prompted the errors encountered in finding the implementations I listed (VisualStudioCode,VisualStudio), but it's not critical.

[SimonCropp]

given on your machine F:\Programs\Microsoft VS Code is in path and Code.exe then this code should find it https://github.com/VerifyTests/DiffEngine/blob/main/src/DiffEngine/OsSettingsResolver.cs#L109

[SimonCropp]

closing this for now. if u can share a failing unit test as a PR we can look at it again

[ldeluigi]

This works:

This doesn't:

[ldeluigi]

Another way to make it work is to put the entire Vs Code installation folder in the PATH, isntead of just the bin folder

[ldeluigi]

In that case it finds the Code.exe file

[ldeluigi]

@SimonCropp can you make it look for either a Code.exe or a code file?

[SimonCropp]

Another way to make it work is to put the entire Vs Code installation folder in the PATH, isntead of just the bin folder
In that case it finds the Code.exe file

yep. and isnt that the fix for you?

[ldeluigi]

Another way to make it work is to put the entire Vs Code installation folder in the PATH, isntead of just the bin folder
In that case it finds the Code.exe file

yep. and isnt that the fix for you?

It would be, but I'd rather avoid adding that folder to the path given that it's necessary just for DiffEngine.

[ldeluigi]

I want to stress the fact that forcing a parsing of the system PATH it's not a very good practice in general. One should be able to configure exact specific paths to executables of their diff programs. This avoids mistakes and confusion on which executable the engine is running in case of multiple installation of the same program and some other edge cases...

[SimonCropp]

configure exact specific paths to executables of their diff programs

if u want to do a pull request for that, i am happy to consider it