Added checker for the pid offset between two channels

tests/test_utils.py

@@ -2,8 +2,8 @@ import pytest
 import os
 import numpy as np
 import cristallina.utils as utils
-
-from cristallina.utils import ROI, print_run_info, heuristic_extract_pgroup, gauss, find_nearest, xray_transmission,stand_table
+from sfdata import SFDataFiles
+from cristallina.utils import ROI, print_run_info, heuristic_extract_pgroup, gauss, find_nearest, xray_transmission,stand_table,check_pid_offset
 
 
 def test_print(capsys):
@@ -30,8 +30,10 @@ def test_ROI():
     
     
 def test_extract_pgroup():
+    cwd = os.getcwd()
     os.chdir("tests/data/p20841/raw/")
     assert heuristic_extract_pgroup() == '20841'
+    os.chdir(cwd)
 
 
 def test_gauss():
@@ -47,6 +49,9 @@ def test_xray_transmission():
     T = xray_transmission(9000, 100e-6, material = 'Si')
     assert T == 0.342385039732607
 
+def test_check_pid_offset():
+    with SFDataFiles(f"tests/data/p20841/raw/run0205/data/acq*.h5") as data:
+        assert check_pid_offset(data,'SARFE10-PBPG050:HAMP-INTENSITY-CAL','SARFE10-PBIG050-EVR0:CALCI') == 0
 
 # This test can only be run localy (github has no access to /sf/cristallina), therefore it's commented out.