test: add business logic tests for envelope folder management

Add unit tests focused on validating business rules:
- Envelope folder name must include user-defined name and UUID
- getFolderForFile() must use existing envelope folder when
  envelopeFolderId is provided
- getFolderForFile() must create new folder when no envelope
  context exists

Tests focus on behavior validation rather than implementation
details, using minimal mocking.

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

tests/php/Unit/Service/EnvelopeServiceTest.php

@@ -163,4 +163,27 @@ public function testReturnsEnvelopeWhenFileHasParent(): void {
 		$this->assertNotNull($result);
 		$this->assertSame(5, $result->getId());
 	}
+
+	public function testEnvelopeUuidMatchesFolderName(): void {
+		$this->fileMapper->method('insert')->willReturnArgument(0);
+
+		$mockFolder = $this->createMock(Folder::class);
+		$mockEnvelopeFolder = $this->createMock(Folder::class);
+		$mockEnvelopeFolder->method('getId')->willReturn(999);
+
+		$capturedFolderName = '';
+		$mockFolder->method('newFolder')->willReturnCallback(
+			function ($folderName) use ($mockEnvelopeFolder, &$capturedFolderName) {
+				$capturedFolderName = $folderName;
+				return $mockEnvelopeFolder;
+			}
+		);
+
+		$this->folderService->method('getFolder')->willReturn($mockFolder);
+
+		$envelope = $this->service->createEnvelope('Contract', 'user1');
+
+		$this->assertStringStartsWith('Contract_', $capturedFolderName);
+		$this->assertStringContainsString($envelope->getUuid(), $capturedFolderName);
+	}
 }

tests/php/Unit/Service/FolderServiceTest.php

@@ -274,4 +274,64 @@ public static function providerGetFolderName(): array {
 			],
 		];
 	}
+
+	public function testGetFolderForFileUsesEnvelopeFolderWhenProvided(): void {
+		$envelopeFolderId = 456;
+		$data = [
+			'settings' => [
+				'envelopeFolderId' => $envelopeFolderId,
+			],
+		];
+
+		$mockUserFolder = $this->createMock(Folder::class);
+		$mockEnvelopeFolder = $this->createMock(Folder::class);
+
+		$mockUserFolder->expects($this->once())
+			->method('getFirstNodeById')
+			->with($envelopeFolderId)
+			->willReturn($mockEnvelopeFolder);
+
+		$this->appConfig->method('getUserValue')->willReturn('/LibreSign');
+		$this->groupManager->method('isInGroup')->willReturn(false);
+
+		$userFolder = $this->createMock(Folder::class);
+		$userFolder->method('isUpdateable')->willReturn(true);
+		$userFolder->method('get')->willReturn($mockUserFolder);
+		$this->root->method('getUserFolder')->willReturn($userFolder);
+
+		$service = $this->getInstance('testuser');
+		$result = $service->getFolderForFile($data, 'testuser');
+
+		$this->assertInstanceOf(Folder::class, $result);
+	}
+
+	public function testGetFolderForFileCreatesNewFolderWhenNoEnvelopeId(): void {
+		$data = [
+			'name' => 'Document',
+			'settings' => [],
+		];
+
+		$user = $this->createMock(IUser::class);
+		$user->method('getUID')->willReturn('user1');
+
+		$mockUserFolder = $this->createMock(Folder::class);
+		$mockNewFolder = $this->createMock(Folder::class);
+
+		$mockUserFolder->expects($this->once())
+			->method('newFolder')
+			->willReturn($mockNewFolder);
+
+		$this->appConfig->method('getUserValue')->willReturn('/LibreSign');
+		$this->groupManager->method('isInGroup')->willReturn(false);
+
+		$userFolder = $this->createMock(Folder::class);
+		$userFolder->method('isUpdateable')->willReturn(true);
+		$userFolder->method('get')->willReturn($mockUserFolder);
+		$this->root->method('getUserFolder')->willReturn($userFolder);
+
+		$service = $this->getInstance('user1');
+		$result = $service->getFolderForFile($data, $user);
+
+		$this->assertInstanceOf(Folder::class, $result);
+	}
 }