Fix file.move failing on 2nd move when createParentDirectories=true and overwrite=true

[GDLMadushanka]

Summary

Fixes wso2/product-integrator-mi#4934
The file.move operation fails with FileSystemException: Could not create folder "...abc.txt" because it already exists and is a file on every move after the first, when createParentDirectories=true and overwrite=true are both set.

Root Cause

MoveFiles.moveFile() (line 289) was calling createFolder() on the full destination file path instead of the destination's parent directory:

// BEFORE (buggy)
if (createNonExistingParents) {
    destinationFile.createFolder();   // called on the file path, not the parent
}

• Run 1: /target/abc.txt does not exist → VFS creates it as a folder, then moveTo() overwrites it with the file. Works by accident.
• Run 2: /target/abc.txt already exists as a regular file → VFS refuses to create a folder where a file already exists → FileSystemException. Because this exception is thrown before moveTo(), overwrite=true is silently ineffective.

Fix

Resolve destinationFile.getParent() and call createFolder() only when the parent is non-null and does not yet exist:

// AFTER (fixed)
if (createNonExistingParents) {
    FileObject parent = destinationFile.getParent();
    if (parent != null && !parent.exists()) {
        parent.createFolder();
    }
}

The !overWrite && destinationFile.exists() guard, the else/debug-log branch, and srcFile.moveTo(destinationFile) are unchanged. The moveFolder path is untouched.

Files Changed

File	Change
src/main/java/org/wso2/carbon/connector/operations/MoveFiles.java	Replace destinationFile.createFolder() with guarded parent-directory creation
src/test/java/org/wso2/carbon/connector/operations/MoveFilesParentDirectoryTest.java	New: 5 unit tests for MoveFiles.moveFile() (see below)
src/test/resources/testng-unit.xml	Register MoveFilesParentDirectoryTest in the unit suite

Tests Added

MoveFiles previously had zero automated tests. Added MoveFilesParentDirectoryTest (5 tests) using a real StandardFileSystemManager against a temp directory — no MI server or carbon zip required:

#	Scenario	What it verifies
1	createParentDirectories=true + overwrite=true, move TWICE (the reported regression)	Second move succeeds, dest is a file with run-2 content, source removed
1b	Same scenario with the old buggy createFolder-on-destination logic	Run 2 throws "Could not create folder" — pins the exact bug
2	createParentDirectories=true into a missing target dir	Parent created as a directory, file lands inside as a file
3	createParentDirectories=true + overwrite=false, dest present	Returns false / FileAlreadyExistsException; dest untouched; no folder-creation exception
4	renameTo + createParentDirectories=true into missing dir	Parent created; file moved to renamed destination inside it

Full unit suite result: Tests run: 15, Failures: 0, Skips: 1 (9 pre-existing WriteFileTempFileResolutionTest cases + 5 new cases; 1 skip is the pre-existing smb2 case).

Verification

Independently verified on a freshly extracted WSO2 MI 4.4.0 pack:

• Built connector from fix/issue-5082 working tree (mvn clean package -DskipTests).
• Deployed FILE_CONN (LOCAL, workingDir=/tmp/file5082) + MoveTestAPI (overwrite=true) + MoveNoOverwriteAPI (overwrite=false).
• Run 1: HTTP 200 {"success":true} — file moved, /target created as directory, file inside it.
• Run 2 (the regression): HTTP 200 {"success":true} — destination overwritten, source removed. Zero "Could not create folder" errors in the full server log.
• Parent-dir re-creation check: HTTP 200 — /target recreated, file inside.
• Negative (overwrite=false): correct FileAlreadyExistsException; destination untouched; no folder-creation exception.
• 3 consecutive overwrite moves: all HTTP 200.

grep -c "Could not create folder" across the entire verify session = 0.