Using IF EXIST in commandline task VSTS - command-line

Question

Problem
I want to run an IF EXIST command in my release task in VSTS, but I'm not sure how to split the code up to run commands and the documentation isn't clear on what actually is an argument.
The line I want to run is
IF EXIST C:\Users\user\Documents\folder_name ( rmdir /s folder_to_delete /Q )
If I run it in the commandline it runs just fine, but I can't translate it into VSTS commandline tool fields.
What I've tried
# In Tool field:
IF EXIST 'C:\Users\user\Documents\folder_name' ( rmdir /s 'folder_to_delete' /Q )
# In tool field:
IF EXIST 'C:\Users\user\Documents\folder_name' ( rmdir /s 'C:\path\to\folder_to_delete' /Q )
# In tool field:
IF EXIST C:\Users\user\Documents\folder_name rmdir /s 'folder_to_delete' /Q
# In tool field:
IF EXIST C:\Users\user\Documents\folder_name rmdir folder_to_delete
# In tool field:
IF EXIST C:\Users\user\Documents\folder_name ( rmdir folder_to_delete)
# In Arguments field:
/s /Q
# In tool field:
IF EXIST
# In Arguments field:
C:\Users\user\Documents\folder_name rmdir folder_to_delete
None of those work i any iteration with ' or " dirct or relative paths.
Error Message
The error message I get:
The syntax of the command is incorrect.

Answer 1

TL:DR;
The solution is
# In Tool field:
IF
# In Arguments field:
EXIST C:\Users\user\Documents\folder_name ( rmdir /s folder_to_delete /Q )
The explantation
By taking a look in the widows command documentation we can see that the only command is IF. Everything else is a command.
EXIST is an option command to IF, other examples would be DEFINED and ERRORLEVEL, both of which may be combined with the conditional NOT.
Putting ' around the uri to the folder is optional unless you have spaces in the uri, then they are an option to escaping the spaces.
Since the arguments field is one line field you don't need to use the parenthesis; they are a syntax to allow for your command-line to accept multi-line arguments. As an alternative you can use & example:
# In Tool field:
IF
# In Arguments field:
EXIST C:\Users\user\Documents\folder_name echo removing dir! & rmdir /s folder_to_delete /Q
Syntax will still allow for you to use the parenthesis but it's not required. However, if you wish to combine IF with ELSE you do need them:
IF NOT EXIST folder (mkdir folder) ELSE (echo Folder exists!)