fix: preserve globalids for datasets that use change detection

Closes #341

src/forklift/change_detection.py

@@ -24,6 +24,7 @@
 class ChangeDetection(object):
     '''A class that models data obtained from the change detection tables
     '''
+
     def __init__(self, table_paths, root_folder, hash_table=hash_table):
         self.hash_table = hash_table
         if not arcpy.Exists(hash_table):
@@ -67,11 +68,22 @@ def update(self, crate):
         elif crate.result[0] == Crate.CREATED:
             status = Crate.CREATED
 
-        log.info(f'truncating {crate.destination}')
-        arcpy.management.TruncateTable(crate.destination)
-
-        with arcpy.EnvManager(geographicTransformations=crate.geographic_transformation):
-            arcpy.management.Append(crate.source, crate.destination, schema_type='NO_TEST')
+        if (_has_globalid_field(crate.source)):
+            log.info(f'deleting and copying {crate.destination}')
+            with arcpy.EnvManager(
+                geographicTransformations=crate.geographic_transformation,
+                preserveGlobalIds=True,
+                outputCoordinateSystem=crate.destination_coordinate_system
+            ):
+                arcpy.management.Delete(crate.destination)
+                #: the only way to preserve global id values when exporting to fgdb is to use this tool
+                arcpy.conversion.FeatureClassToFeatureClass(crate.source, crate.destination_workspace, crate.destination_name)
+        else:
+            log.info(f'truncating and loading {crate.destination}')
+            arcpy.management.TruncateTable(crate.destination)
+
+            with arcpy.EnvManager(geographicTransformations=crate.geographic_transformation):
+                arcpy.management.Append(crate.source, crate.destination, schema_type='NO_TEST')
 
         table_name = crate.source_name.lower()
         with arcpy.da.UpdateCursor(self.hash_table, [hash_field], where_clause=f'{table_name_field} = \'{table_name}\'') as cursor:
@@ -87,6 +99,14 @@ def update(self, crate):
         return (status, None)
 
 
+def _has_globalid_field(table):
+    '''table: string - path to a feature class
+
+    returns a boolean indicating if the table has a GlobalId field
+    '''
+    return len(arcpy.ListFields(table, field_type='GlobalID')) > 0
+
+
 def _get_hashes(table_paths):
     '''table_paths: string[] - paths to change detection tables relative to the garage
     root: string - path to root directory where table_paths is relative to

tests/test_change_detection.py

@@ -7,6 +7,7 @@
 import logging
 import unittest
 from os import path
+from pathlib import Path
 
 from pytest import raises
 
@@ -113,3 +114,48 @@ def test_invalid_data(self):
         result = change_detection.update(crate)
 
         self.assertEqual(result[0], Crate.INVALID_DATA)
+
+    def test_preserves_globalids(self):
+        scratch_hash_table = str(Path(arcpy.env.scratchGDB) / Path(hash_table).name)
+        scratch_destination = str(Path(arcpy.env.scratchGDB) / 'GlobalIds')
+        temp_data = [scratch_hash_table, scratch_destination]
+        for dataset in temp_data:
+            if arcpy.Exists(dataset):
+                arcpy.management.Delete(dataset)
+        arcpy.management.Copy(hash_table, scratch_hash_table)
+        test_sde = str(Path(test_data_folder) / 'UPDATE_TESTS.sde')
+
+        change_detection = ChangeDetection(['ChangeDetection'], test_sde, hash_table=scratch_hash_table)
+
+        table = 'GlobalIds'
+        crate = Crate(table, test_sde, str(Path(scratch_destination).parent), Path(scratch_destination).name)
+        crate.result = (Crate.CREATED, None)
+        core._create_destination_data(crate, skip_hash_field=True)
+        change_detection.current_hashes[f'update_tests.dbo.{table.casefold()}'] = 'hash'
+        result = change_detection.update(crate)
+
+        self.assertEqual(result[0], Crate.CREATED)
+
+        with arcpy.da.SearchCursor(scratch_destination, ['GlobalID', 'NAME'], 'NAME = \'JUAB\'') as cursor:
+            self.assertEqual(next(cursor)[0], '{29B2946D-695C-4387-BAB7-4773B8DC0E6D}')
+
+    def test_can_handle_globalid_fields_without_index(self):
+        scratch_hash_table = str(Path(arcpy.env.scratchGDB) / Path(hash_table).name)
+        scratch_destination = str(Path(arcpy.env.scratchGDB) / 'GlobalIds')
+        temp_data = [scratch_hash_table, scratch_destination]
+        for dataset in temp_data:
+            if arcpy.Exists(dataset):
+                arcpy.management.Delete(dataset)
+        arcpy.management.Copy(hash_table, scratch_hash_table)
+        test_sde = str(Path(test_data_folder) / 'UPDATE_TESTS.sde')
+
+        change_detection = ChangeDetection(['ChangeDetection'], test_sde, hash_table=scratch_hash_table)
+
+        table = 'GlobalIdsNoIndex'
+        crate = Crate(table, test_sde, arcpy.env.scratchGDB, Path(scratch_destination).name)
+        crate.result = (Crate.CREATED, None)
+        core._create_destination_data(crate, skip_hash_field=True)
+        change_detection.current_hashes[f'update_tests.dbo.{table.casefold()}'] = 'hash'
+        result = change_detection.update(crate)
+
+        self.assertEqual(result[0], Crate.CREATED)