refactor: ship Custom Fields and Property Setters as module customizations

Move the Sales Invoice withholding fields and both Property Setters from
fixtures to default_thai_company/custom/{sales_invoice,payment_entry}.json
with sync_on_migrate. sync_customizations updates Custom Fields in place
instead of the delete/re-insert that fixtures do on every migrate.

default_thai_company/default_thai_company/custom/payment_entry.json

@@ -0,0 +1,32 @@
+{
+ "custom_fields": [],
+ "custom_perms": [],
+ "doctype": "Payment Entry",
+ "links": [],
+ "property_setters": [
+  {
+   "_assign": null,
+   "_comments": null,
+   "_liked_by": null,
+   "_user_tags": null,
+   "creation": "2026-09-11 17:18:28.670630",
+   "default_value": null,
+   "doc_type": "Payment Entry",
+   "docstatus": 0,
+   "doctype_or_field": "DocField",
+   "field_name": "apply_tax_withholding_amount",
+   "idx": 0,
+   "is_system_generated": 0,
+   "modified": "2026-09-11 12:00:00",
+   "modified_by": "Administrator",
+   "module": null,
+   "name": "Payment Entry-apply_tax_withholding_amount-depends_on",
+   "owner": "Administrator",
+   "property": "depends_on",
+   "property_type": "Data",
+   "row_name": null,
+   "value": "eval:doc.party_type == 'Supplier' || (doc.party_type == 'Customer' && doc.payment_type == 'Receive')"
+  }
+ ],
+ "sync_on_migrate": 1
+}

default_thai_company/default_thai_company/custom/sales_invoice.json

@@ -0,0 +1,225 @@
+{
+ "custom_fields": [
+  {
+   "_assign": null,
+   "_comments": null,
+   "_liked_by": null,
+   "_user_tags": null,
+   "allow_in_quick_entry": 0,
+   "allow_on_submit": 0,
+   "bold": 1,
+   "collapsible": 0,
+   "collapsible_depends_on": null,
+   "columns": 0,
+   "creation": "2026-09-11 17:18:48.182536",
+   "default": null,
+   "depends_on": "eval:doc.tax_withholding_category",
+   "description": null,
+   "docstatus": 0,
+   "dt": "Sales Invoice",
+   "fetch_from": null,
+   "fetch_if_empty": 0,
+   "fieldname": "amount_after_withholding",
+   "fieldtype": "Currency",
+   "hidden": 0,
+   "hide_border": 0,
+   "hide_days": 0,
+   "hide_seconds": 0,
+   "idx": 80,
+   "ignore_user_permissions": 0,
+   "ignore_xss_filter": 0,
+   "in_global_search": 0,
+   "in_list_view": 0,
+   "in_preview": 0,
+   "in_standard_filter": 0,
+   "insert_after": "withholding_tax_amount",
+   "is_system_generated": 0,
+   "is_virtual": 0,
+   "label": "Net Payable After Withholding Tax",
+   "length": 0,
+   "link_filters": null,
+   "mandatory_depends_on": null,
+   "modified": "2026-09-11 17:18:48.182536",
+   "modified_by": "Administrator",
+   "module": null,
+   "name": "Sales Invoice-amount_after_withholding",
+   "no_copy": 1,
+   "non_negative": 0,
+   "options": "currency",
+   "owner": "Administrator",
+   "permlevel": 0,
+   "placeholder": null,
+   "precision": null,
+   "print_hide": 0,
+   "print_hide_if_no_value": 1,
+   "print_width": null,
+   "read_only": 1,
+   "read_only_depends_on": null,
+   "report_hide": 0,
+   "reqd": 0,
+   "search_index": 0,
+   "show_dashboard": 0,
+   "sort_options": 0,
+   "translatable": 0,
+   "unique": 0,
+   "width": null
+  },
+  {
+   "_assign": null,
+   "_comments": null,
+   "_liked_by": null,
+   "_user_tags": null,
+   "allow_in_quick_entry": 0,
+   "allow_on_submit": 0,
+   "bold": 0,
+   "collapsible": 0,
+   "collapsible_depends_on": null,
+   "columns": 0,
+   "creation": "2026-09-11 17:18:44.710456",
+   "default": null,
+   "depends_on": null,
+   "description": null,
+   "docstatus": 0,
+   "dt": "Sales Invoice",
+   "fetch_from": "customer.tax_withholding_category",
+   "fetch_if_empty": 1,
+   "fieldname": "tax_withholding_category",
+   "fieldtype": "Link",
+   "hidden": 0,
+   "hide_border": 0,
+   "hide_days": 0,
+   "hide_seconds": 0,
+   "idx": 57,
+   "ignore_user_permissions": 0,
+   "ignore_xss_filter": 0,
+   "in_global_search": 0,
+   "in_list_view": 0,
+   "in_preview": 0,
+   "in_standard_filter": 0,
+   "insert_after": "taxes_and_charges",
+   "is_system_generated": 0,
+   "is_virtual": 0,
+   "label": "Tax Withholding Category",
+   "length": 0,
+   "link_filters": null,
+   "mandatory_depends_on": null,
+   "modified": "2026-09-11 18:00:00",
+   "modified_by": "Administrator",
+   "module": null,
+   "name": "Sales Invoice-tax_withholding_category",
+   "no_copy": 0,
+   "non_negative": 0,
+   "options": "Tax Withholding Category",
+   "owner": "Administrator",
+   "permlevel": 0,
+   "placeholder": null,
+   "precision": null,
+   "print_hide": 1,
+   "print_hide_if_no_value": 0,
+   "print_width": null,
+   "read_only": 0,
+   "read_only_depends_on": null,
+   "report_hide": 0,
+   "reqd": 0,
+   "search_index": 0,
+   "show_dashboard": 0,
+   "sort_options": 0,
+   "translatable": 0,
+   "unique": 0,
+   "width": null
+  },
+  {
+   "_assign": null,
+   "_comments": null,
+   "_liked_by": null,
+   "_user_tags": null,
+   "allow_in_quick_entry": 0,
+   "allow_on_submit": 0,
+   "bold": 0,
+   "collapsible": 0,
+   "collapsible_depends_on": null,
+   "columns": 0,
+   "creation": "2026-09-11 17:18:47.244523",
+   "default": null,
+   "depends_on": "eval:doc.tax_withholding_category",
+   "description": null,
+   "docstatus": 0,
+   "dt": "Sales Invoice",
+   "fetch_from": null,
+   "fetch_if_empty": 0,
+   "fieldname": "withholding_tax_amount",
+   "fieldtype": "Currency",
+   "hidden": 0,
+   "hide_border": 0,
+   "hide_days": 0,
+   "hide_seconds": 0,
+   "idx": 79,
+   "ignore_user_permissions": 0,
+   "ignore_xss_filter": 0,
+   "in_global_search": 0,
+   "in_list_view": 0,
+   "in_preview": 0,
+   "in_standard_filter": 0,
+   "insert_after": "rounded_total",
+   "is_system_generated": 0,
+   "is_virtual": 0,
+   "label": "Withholding Tax",
+   "length": 0,
+   "link_filters": null,
+   "mandatory_depends_on": null,
+   "modified": "2026-09-11 18:00:00",
+   "modified_by": "Administrator",
+   "module": null,
+   "name": "Sales Invoice-withholding_tax_amount",
+   "no_copy": 1,
+   "non_negative": 0,
+   "options": "currency",
+   "owner": "Administrator",
+   "permlevel": 0,
+   "placeholder": null,
+   "precision": null,
+   "print_hide": 0,
+   "print_hide_if_no_value": 1,
+   "print_width": null,
+   "read_only": 1,
+   "read_only_depends_on": null,
+   "report_hide": 0,
+   "reqd": 0,
+   "search_index": 0,
+   "show_dashboard": 0,
+   "sort_options": 0,
+   "translatable": 0,
+   "unique": 0,
+   "width": null
+  }
+ ],
+ "custom_perms": [],
+ "doctype": "Sales Invoice",
+ "links": [],
+ "property_setters": [
+  {
+   "_assign": null,
+   "_comments": null,
+   "_liked_by": null,
+   "_user_tags": null,
+   "creation": "2026-09-11 17:18:28.581896",
+   "default_value": null,
+   "doc_type": "Sales Invoice",
+   "docstatus": 0,
+   "doctype_or_field": "DocType",
+   "field_name": null,
+   "idx": 0,
+   "is_system_generated": 1,
+   "modified": "2026-09-10 13:55:13.996942",
+   "modified_by": "Administrator",
+   "module": null,
+   "name": "Sales Invoice-main-default_print_format",
+   "owner": "Administrator",
+   "property": "default_print_format",
+   "property_type": "Data",
+   "row_name": null,
+   "value": "Default Standard Sales Invoice"
+  }
+ ],
+ "sync_on_migrate": 1
+}

default_thai_company/fixtures/custom_field.json

@@ -1,50 +0,0 @@
-[
- {
-  "docstatus": 0,
-  "doctype": "Custom Field",
-  "dt": "Sales Invoice",
-  "fetch_from": "customer.tax_withholding_category",
-  "fetch_if_empty": 1,
-  "fieldname": "tax_withholding_category",
-  "fieldtype": "Link",
-  "insert_after": "taxes_and_charges",
-  "label": "Tax Withholding Category",
-  "modified": "2026-09-11 18:00:00.000000",
-  "name": "Sales Invoice-tax_withholding_category",
-  "options": "Tax Withholding Category",
-  "print_hide": 1
- },
- {
-  "depends_on": "eval:doc.tax_withholding_category",
-  "docstatus": 0,
-  "doctype": "Custom Field",
-  "dt": "Sales Invoice",
-  "fieldname": "withholding_tax_amount",
-  "fieldtype": "Currency",
-  "insert_after": "rounded_total",
-  "label": "Withholding Tax",
-  "modified": "2026-09-11 18:00:00.000000",
-  "name": "Sales Invoice-withholding_tax_amount",
-  "no_copy": 1,
-  "options": "currency",
-  "print_hide_if_no_value": 1,
-  "read_only": 1
- },
- {
-  "bold": 1,
-  "depends_on": "eval:doc.tax_withholding_category",
-  "docstatus": 0,
-  "doctype": "Custom Field",
-  "dt": "Sales Invoice",
-  "fieldname": "amount_after_withholding",
-  "fieldtype": "Currency",
-  "insert_after": "withholding_tax_amount",
-  "label": "Net Payable After Withholding Tax",
-  "modified": "2026-09-11 18:00:00.000000",
-  "name": "Sales Invoice-amount_after_withholding",
-  "no_copy": 1,
-  "options": "currency",
-  "print_hide_if_no_value": 1,
-  "read_only": 1
- }
-]

default_thai_company/fixtures/property_setter.json

@@ -1,34 +0,0 @@
-[
- {
-  "default_value": null,
-  "doc_type": "Sales Invoice",
-  "docstatus": 0,
-  "doctype": "Property Setter",
-  "doctype_or_field": "DocType",
-  "field_name": null,
-  "is_system_generated": 1,
-  "modified": "2026-09-10 13:55:13.996942",
-  "module": null,
-  "name": "Sales Invoice-main-default_print_format",
-  "property": "default_print_format",
-  "property_type": "Data",
-  "row_name": null,
-  "value": "Default Standard Sales Invoice"
- },
- {
-  "default_value": null,
-  "doc_type": "Payment Entry",
-  "docstatus": 0,
-  "doctype": "Property Setter",
-  "doctype_or_field": "DocField",
-  "field_name": "apply_tax_withholding_amount",
-  "is_system_generated": 0,
-  "modified": "2026-09-11 12:00:00.000000",
-  "module": null,
-  "name": "Payment Entry-apply_tax_withholding_amount-depends_on",
-  "property": "depends_on",
-  "property_type": "Data",
-  "row_name": null,
-  "value": "eval:doc.party_type == 'Supplier' || (doc.party_type == 'Customer' && doc.payment_type == 'Receive')"
- }
-]

default_thai_company/hooks.py

@@ -84,38 +84,13 @@ jinja = {
 # Fixtures
 # --------
 
+# Custom Fields and Property Setters live in default_thai_company/custom/*.json
+# (synced in place on install and migrate); fixtures are for whole documents.
 fixtures = [
 	{"doctype": "Letter Head", "filters": [["name", "in", ["Default Letter Head"]]]},
 	{"doctype": "Address Template", "filters": [["name", "in", ["Thailand"]]]},
 	{"doctype": "Print Format", "filters": [["name", "in", ["Default Standard Sales Invoice"]]]},
-	{
-		"doctype": "Property Setter",
-		"filters": [
-			[
-				"name",
-				"in",
-				[
-					"Sales Invoice-main-default_print_format",
-					"Payment Entry-apply_tax_withholding_amount-depends_on",
-				],
-			]
-		],
-	},
 	{"doctype": "Tax Withholding Category", "filters": [["name", "like", "WHT %"]]},
-	{
-		"doctype": "Custom Field",
-		"filters": [
-			[
-				"name",
-				"in",
-				[
-					"Sales Invoice-tax_withholding_category",
-					"Sales Invoice-withholding_tax_amount",
-					"Sales Invoice-amount_after_withholding",
-				],
-			]
-		],
-	},
 ]
 
 # Installation

default_thai_company/tests/test_tax_withholding.py

@@ -1,5 +1,8 @@
+import json
+
 import frappe
 from frappe.modules.import_file import import_file_by_path
+from frappe.modules.utils import sync_customizations_for_doctype
 from frappe.tests.utils import FrappeTestCase
 from frappe.utils import nowdate
 
@@ -10,7 +13,7 @@ ABBR = "_TWC"
 CUSTOMER = "_Test WHT Customer"
 ITEM = "_Test WHT Service"
 FIXTURE = frappe.get_app_path("default_thai_company", "fixtures", "tax_withholding_category.json")
-CUSTOM_FIELDS = frappe.get_app_path("default_thai_company", "fixtures", "custom_field.json")
+CUSTOM_DIR = frappe.get_app_path("default_thai_company", "default_thai_company", "custom")
 
 
 class TestTaxWithholding(FrappeTestCase):
@@ -20,8 +23,9 @@ class TestTaxWithholding(FrappeTestCase):
 		# Fixture categories must exist before the company is created so the
 		# Company hook has something to link; force=True re-imports.
 		import_file_by_path(FIXTURE, force=True, data_import=True)
-		import_file_by_path(CUSTOM_FIELDS, force=True, data_import=True)
+		for fname in ("sales_invoice.json", "payment_entry.json"):
-		frappe.clear_cache(doctype="Sales Invoice")
+			with open(f"{CUSTOM_DIR}/{fname}") as f:
+				sync_customizations_for_doctype(json.load(f), CUSTOM_DIR, fname)
 
 		frappe.get_doc(
 			{