Add extra target folder validation on cmta commands

- `cmta linearize` was missing target folder validation
  altogether
- Added target folder validation on `cmta studentify` and
  `cmta linearize` commands

cmta/src/main/scala/com/lunatech/cmt/admin/TargetFolderValidation.scala

@@ -0,0 +1,20 @@
+package com.lunatech.cmt.admin
+
+import com.lunatech.cmt.CmtError
+import java.io.File
+import com.lunatech.cmt.toExecuteCommandErrorMessage
+
+def validateTargetFolder(mainRepository: File, target: File): Either[CmtError, Unit] =
+  val canonicalStudentifyBaseDirectory = target.getCanonicalPath
+  val canonicalMainRepository = mainRepository.getCanonicalPath
+  val mainRepositoryEqualsStudentifyBaseDirectory = canonicalStudentifyBaseDirectory == canonicalMainRepository
+  val StudentifyBaseDirectoryIsSubfolderOfmainRepository =
+    canonicalStudentifyBaseDirectory.startsWith(canonicalMainRepository)
+  (mainRepositoryEqualsStudentifyBaseDirectory, StudentifyBaseDirectoryIsSubfolderOfmainRepository) match {
+    case (true, _) =>
+      Left("destination folder cannot be the same as the main repository root folder".toExecuteCommandErrorMessage)
+    case (_, true) =>
+      Left("destination folder cannot be a subfolder of the main repository".toExecuteCommandErrorMessage)
+    case _ =>
+      Right(())
+  }

cmta/src/main/scala/com/lunatech/cmt/admin/command/Linearize.scala

@@ -6,6 +6,7 @@ import com.lunatech.cmt.{CMTaConfig, CmtError, printResult, toConsoleGreen}
 import com.lunatech.cmt.admin.Domain.{ForceDeleteDestinationDirectory, LinearizeBaseDirectory, MainRepository}
 import com.lunatech.cmt.admin.cli.ArgParsers.{forceDeleteDestinationDirectoryArgParser, linearizeBaseDirectoryArgParser}
 import com.lunatech.cmt.admin.cli.SharedOptions
+import com.lunatech.cmt.admin.validateTargetFolder
 import com.lunatech.cmt.core.cli.CmtCommand
 import com.lunatech.cmt.core.execution.Executable
 import com.lunatech.cmt.core.validation.Validatable
@@ -30,7 +31,10 @@ object Linearize:
   given Validatable[Linearize.Options] with
     extension (options: Linearize.Options)
       def validated(): Either[CmtError, Linearize.Options] =
-        Right(options)
+        for {
+          mainRepository <- resolveMainRepoPath(options.shared.mainRepository.value)
+          _ <- validateTargetFolder(mainRepository, options.linearizeBaseDirectory.value)
+        } yield options
   end given
 
   given Executable[Linearize.Options] with

cmta/src/main/scala/com/lunatech/cmt/admin/command/Studentify.scala

@@ -12,7 +12,7 @@ import com.lunatech.cmt.core.execution.Executable
 import com.lunatech.cmt.{CMTaConfig, CmtError, printResult, toConsoleGreen}
 import sbt.io.IO as sbtio
 import sbt.io.syntax.*
-import com.lunatech.cmt.admin.*
+import com.lunatech.cmt.admin.validateTargetFolder
 import com.lunatech.cmt.admin.cli.SharedOptions
 import com.lunatech.cmt.core.validation.Validatable
 import com.lunatech.cmt.admin.cli.ArgParsers.{
@@ -22,7 +22,6 @@ import com.lunatech.cmt.admin.cli.ArgParsers.{
 }
 import com.lunatech.cmt.core.GeneratorInfo
 import com.lunatech.cmt.core.cli.CmtCommand
-import com.lunatech.cmt.toExecuteCommandErrorMessage
 
 object Studentify:
 
@@ -46,11 +45,10 @@ object Studentify:
   given Validatable[Studentify.Options] with
     extension (options: Studentify.Options)
       def validated(): Either[CmtError, Studentify.Options] =
-        if (options.studentifyBaseDirectory.value.equals(options.shared.mainRepository.value)) {
-          Left("main repository cannot be the same as the destination directory".toExecuteCommandErrorMessage)
-        } else {
-          Right(options)
-        }
+        for {
+          mainRepository <- resolveMainRepoPath(options.shared.mainRepository.value)
+          _ <- validateTargetFolder(mainRepository, options.studentifyBaseDirectory.value)
+        } yield options
       end validated
   end given