fix: Copy DICOM files into temp_dir so dcm2niix can process them

[Devguru-codes]

The convert() method in dicom_to_nifti_converter.py creates a temporary directory and reads DICOM headers, but never copies the actual DICOM files into it. The os.listdir(temp_dir) check always finds it empty and returns early, so dcm2niix is never called. This fixes #40

Fix

 import json
 import os
 import re
+import shutil
 import subprocess
 import tempfile

         with tempfile.TemporaryDirectory() as temp_dir:
             for dcm_file in dcm_files:
+                # Copy DICOM file into temp_dir so dcm2niix can process it
+                shutil.copy2(dcm_file, temp_dir)
 
                 ds = pydicom.dcmread(dcm_file)

File Changed

• package/src/pyaslreport/converters/dicom_to_nifti_converter.py

---

API/Converter Response Comparison

main branch (before fix)

Input: 2 valid DICOM files
Converter Output:
  converted_files:     None
  nifti_file:          None
  error_msg:           No DICOM files found.

>> BUG PRESENT: Converter returned 'No DICOM files found.' despite valid DICOM input.
   Root cause: Files were never copied to temp_dir.

DICOM_Converter_Fix branch (after fix)

Input: 2 valid DICOM files
Converter Output:
  error_msg:           (attempted dcm2niix — not installed on test system)

>> BUG FIXED: Converter progressed past empty-dir check and attempted dcm2niix.
   Files were successfully copied to temp_dir.

---

Python Test Suite Results

main branch (before fix)

#	Test	Status	Detail
T1	convert() copies files into temp_dir	FAIL	No copy operation found
T2	temp_dir receives files before dcm2niix	FAIL	Nothing written
T3	os.listdir doesn't cause false early return	FAIL	Always empty
T4	Module imports shutil	FAIL	Not imported

Summary: PASSED=0 FAILED=4

DICOM_Converter_Fix branch (after fix)

#	Test	Status	Detail
T1	convert() copies files into temp_dir	PASS
T2	temp_dir receives files before dcm2niix	PASS
T3	os.listdir doesn't cause false early return	PASS
T4	Module imports shutil	PASS

Summary: PASSED=4 FAILED=0